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Direction and timing of uplift propagation in the Peruvian Andes deduced from molecular phylogenetics of highland biotaxa
Abstract
Physical paleoaltimetric methods are increasingly used to estimate the amount and timing of surface uplift in orogens. Because the rise of mountains creates new ecosystems and triggers evolutionary changes, biological data may also be used to assess the development and timing of regional surface uplift. Here we apply this idea to the Peruvian Andes through a molecular phylogeographic and phylochronologic analysis of Globodera pallida, a potato parasite nematode that requires cool temperatures and thus thrives above 2.0–2.5 km in these tropical highlands. The Peruvian populations of this species exhibit a clear evolutionary pattern with deeper, more ancient lineages occurring in Andean southern Peru and shallower, younger lineages occurring progressively northwards. Genetically diverging G. pallida populations thus progressively colonized highland areas as these were expanding northwards, demonstrating that altitude in the Peruvian Andes was acquired longitudinally from south to north, i.e. in the direction of decreasing orogenic volume. This phylogeographic structure is recognized in other, independent highland biotaxa, and point to the Central Andean Orocline (CAO) as the region where high altitudes first emerged. Moreover, molecular clocks relative to Andean taxa, including the potato–tomato group, consistently estimate that altitudes high enough to induce biotic radiation were first acquired in the Early Miocene. After calibration by geological and biological tie-points and intervals, the phylogeny of G. pallida is used as a molecular clock, which estimates that the 2.0–2.5 km threshold elevation range was reached in the Early Miocene in southernmost Peru, in the Middle and Late Miocene in the Abancay segment (NW southern Peru), and from the latest Miocene in central and northern Peru. Although uncertainties attached to phylochronologic ages are significantly larger than those derived from geochronological methods, these results are fairly consistent with coeval geological phenomena along the Peruvian Andes. They strongly suggest that orogenic volume initially developed in the CAO during most of the Miocene until a breakthrough in the latest Miocene allowed the northward propagation of crustal thickening into central and northern Peru, possibly by ductile crustal flow from the CAO. Such a combined phylogeographic and phylochronologic approach to regional uplift opens perspectives to estimate the direction(s) and timing of acquisition of altitude over other Cenozoic orogens.
... Roderick, 2014; Guerrero et al., 2013;Luebert et al., 2011b;Picard et al., 2008). Selection pressure on isolated communities will give rise to new phenotypes in floral and faunal populations and eventually to endemic species (Grenier et al., 2010;Luebert et al., 2011a;Schwarzer et al., 2010). ...
... Selection pressure on isolated communities will give rise to new phenotypes in floral and faunal populations and eventually to endemic species (Grenier et al., 2010;Luebert et al., 2011a;Schwarzer et al., 2010). By relating the phylogenetic relationships to ancestor populations, the timing of isolation can be inferred using modern molecular dating techniques (relaxed ‗molecular clock ';Antonelli et al., 2009;Guerrero et al., 2013;Jabbour and Renner, 2012;Luebert et al., 2011b;Macqueen et al., 2011;Picard et al., 2008;Weir and Price, 2011). A continuing challenge is linking this chronological information from molecular dating approaches to paleoclimatic reconstructions and/or changes in the landscape (Picard et al., 2008). ...
... By relating the phylogenetic relationships to ancestor populations, the timing of isolation can be inferred using modern molecular dating techniques (relaxed ‗molecular clock ';Antonelli et al., 2009;Guerrero et al., 2013;Jabbour and Renner, 2012;Luebert et al., 2011b;Macqueen et al., 2011;Picard et al., 2008;Weir and Price, 2011). A continuing challenge is linking this chronological information from molecular dating approaches to paleoclimatic reconstructions and/or changes in the landscape (Picard et al., 2008). If this challenge can be met, emerging novel hypotheses on relationships between climate (change) -Earth surface and biological evolution (Corenblit et al., 2011) can be tested. ...
At the land surface, the availability of water controls the evolution of life as well as the morphological development. It is currently hardly known how far both evolutionary processes interact in water-limited environments. While it is well considered that biotic processes contribute to weathering and therewith also prepare the landscape for erosion, little is known to what degree different landforms form barriers and corridors of life across geological time scales. Here, we present an example of how to tackle this complex interplay of biology and landscape evolution by introducing the Collaborative Research Centre CRC 1211 ‘Earth – Evolution at the dry limit’. A CRC is a German Research Foundation funding program, bringing together scientists from different disciplines to tackle jointly complex emergent research questions for up to twelve years. The CRC 1211 focuses on the arid cores of the Atacama Desert and the Namib Desert. Main objective is to disentangle how the shaping of land-surfaces by past episodes of wetter climate coevolved with the evolution of life. It is hypothesized that aridity was interrupted by punctuated wetter periods, which left fingerprints in surface processes and the radiation of the biota, with climatic thresholds beyond which biota could adapt to and influence landscape development. Specific desert landscape elements such as soil surface crusts, desiccation cracks and subsoil water potentially form underexplored refugia of life at particular sites, while old channels and alluvial fan systems potentially structure its dispersal at small to intermediate scales (< 100m²), In addition, there are large-scale (>10,000 km²) gradients in surface processes and biodiversity, likely controlled by the intensity and duration of fog or rainfall. To substantiate these hypotheses we combine expertise from the fields of population and (phylo-)genetics, molecular biology, biogeography, ecology, soil sciences, Earth-surface sciences, geomorphology, meteorology, (paleo-) climatology, (isotope-) geochemistry and physical dating to discover and evaluate the trajectories and thresholds of the evolution and isolation of life. While presenting here our current research strategy, we invite scientists from all over the world to link their research on related questions for the joint development of a global picture on how evolution of life was triggered and regulated by land-surface processes.
... Topography and climate gradients in the Atacama Desert may significantly control the recent distribution of organisms (Picard et al., 2008). Its extension is restricted by the Pacific Ocean to the west, and the rising Andes to the east, and covers the area from southern Peru in the north to the area around La Serena (Chile) in the south. ...
... As one hypothesis of our study it was assumed that plant radiation is younger than the onset of relatively constant hyperaridity (Picard et al., 2008;Böhnert et al., 2019) and that associated eukaryotic microbe communities show a relatively low divergence (if any) from related plant communities. Second, for several beetles, divergence has occurred already in the Atacama Desert (Zúñiga-Reinoso et al., 2019). ...
... (3) a major re-organisation of plant species to new climatic conditions, including new habitats due to pristine unpopulated high altitude areas (Picard et al., 2008) and also the creation of a geographical barrier for migration of organisms over the Andes, such as plants (see also Böhnert et al., this issues). Younger divergence events most likely have followed specific divergence processes within the Atacama Desert due to the evolution towards hyper-aridity throughout the Atacama Desert (expansion of arid conditions towards eastern and higher elevated areas, Hartley and Chong, 2002;Evenstar et al., 2016;Jordan et al., 2014). ...
Unicellular eukaryotes, also called protists, are potentially fast evolving organisms. The small size of protists, their fast reproduction rate and ability to form cysts as well as their adaptability to extreme conditions allow them to associate to endemic animals, plants, saline lakes and soil even in extremely arid systems. These properties make unicellular eukaryotes ideal model organisms to combine studies on evolutionary processes of very different groups of organisms and across very different time scales comprising even geological ones. The hyperarid Atacama Desert offers a study area unique on Earth, where a predominantly arid climate was present for millions of years.
A comprehensive analysis of the diversity of unicellular eukaryotes in different habitats (endemic desert plant phyllosphere, the gut of endemic darkling beetles, isolated hypersaline waters) revealed a dataset distinct and divergent from other regions on Earth. We used standard isolation and cultivation protocols to elucidate divergence patterns for a variety of very different and independent taxonomic groups of protists such as gregarines and ciliates among alveolates, placidids among stramenopiles and choanoflagellates among opisthokonts. The ability to rapidly adapt to extreme environments, which enhance a fast divergence rate at high UV radiation, has only been reported for prokaryotes up to now. The establishment of arid to hyperarid conditions in the Atacama Desert about 20 Ma ago has obviously led to an isolation of protist populations followed by a radiation of species. There are only a few regions on Earth with similar extreme salinity conditions reducing the chance of an exchange between protist populations. Divergence patterns in unicellular eukaryotes in very different phylogenetic groups independently mirror the effect of geological evolution and climate variability during the Neogene.
... Methods applied to the central Andes have been based on timing of crustal shortening 16 , or on geomorphic features such as regional tilt and monocline development 20,21 , paleosurface peneplain mapping 22 , and river incision 23 . Alternatively, biological proxies, such as phylogenetics of high-elevation biotaxa 24 and leaf physiognomy 25 , have been used to infer surface uplift of the central Andes. More recently developed paleoelevation proxies exploit the stable isotopic record by measuring δ 18 O in soil carbonates 9 , mean annual air temperatures inferred from clumped isotope Δ 47 variations in carbonate 26 , and paleoenvironmental waters preserved in hydrated volcanic glass [27][28][29] . ...
... Results for the southern Western Cordillera and northern Altiplano are consistent with paleoelevation estimates from leaf physiognomy suggesting these regions attained no more than half their modern day elevations by . These results are within uncertainty of elevation estimates based on molecular phylogenetics and phylochronologic analysis that require at least 2 km elevation in the early Miocene in southernmost Peru in order to sustain high-elevation-dwelling Globodera pallida potato parasite nematodes 24 . The southern Western Cordillera estimates are also consistent with paleoelevation estimates based on deformation of large-volume ignimbrite deposits that suggest surface uplift started as early as 23 Ma 48 ; regional tilting and monocline development suggesting relative elevation increase of 2 km between 26 and 8 Ma 49 47 ; and GCM with 50 and 100% Andean elevation from Poulsen et al. 31 . ...
... For example, the emerging Eastern Cordillera may have been high enough (~2.5 km) to block moisture-laden air masses as early as 25 Ma (Fig. 5). If the Altiplano was as low as predicted before 15 Ma (~1.5 km), and so too was the Abancay region east of Ayacucho to the north 23,24 , then moisture would have penetrated far into the orogenic hinterland resulting in arid, but not hyperarid conditions along the central Andean Pacific coast, which is consistent with the observed onset of hyperaridity after ~17 Ma 62 . Results of this study documenting variable surface uplift both along-and across-strike provide a new avenue of research focused on tectonic-climate interaction. ...
Changes in Earth’s surface elevation can be linked to the geodynamic processes that drive surface uplift, which in turn modulate regional climate patterns. We document hydrogen isotopic compositions of hydrated volcanic glasses and modern stream waters to determine late Cenozoic surface uplift across the Peruvian central Andes. Modern water isotopic compositions reproduce mean catchment elevations to a precision better than ±500 m (1σ). Glass isotopic data show a spatiotemporally variable transition from isotopically heavy to isotopically light compositions. The latter are consistent with modern water on the plateau. When interpreted in the context of published paleoelevation estimates and independent geological information, the isotopic data indicate that elevation rapidly increased by 2–2.5 km from 20–17 Ma in the central Western Cordillera, and from 15–10 Ma in the southern Western Cordillera and Altiplano; these patterns are consistent with foundering of mantle lithosphere via Rayleigh-Taylor instability. The Eastern Cordillera was slowly elevated 1.5–2 km between 25 and 10 Ma, a rate consistent with crustal shortening as the dominant driver of surface uplift. The Ayacucho region attained modern elevation by ~22 Ma. The timing of orographic development across southern Peru is consistent with the early Miocene onset and middle Miocene intensification of hyperarid conditions along the central Andean Pacific coast.
... The lithospheric structure of the Central Andean Plateau has long been of interest; however, a lack of seismic station coverage, especially in the central and northern Plateau regions, has hampered its imaging. Previous studies in the central Plateau (16 • -21 • S) identified thick crust with slow Kar et al. 2016 Saylor Bershaw et al. 2010Gregory-Wodzicki et al. 1998, Gregory-Wodzicki 2002Leier et al. 2013Graham et al. 2001Garzione et al. 2006, Ghosh et al. 2006Garzione et al. 2014Picard et al. 2008Kennan et al. 1997, Barke & Lamb 2006Hoke et al. 2007Schildgen et al. 2007, Thouret et al. 2007, Schildgen et al. 2009b, Fox et al. 2015 Lease Schildgen et al. 2009aJordan et al. 2010 Balanced cross sections detailed in Figure 8 crustal seismic velocities as well as a variable uppermost mantle with high-velocity material in the uppermost mantle beneath the central part of the Altiplano and low velocities beneath the Eastern Cordillera near the Los Frailes ignimbrite complex (18 • -20 • S) (Myers et al. 1998, Swenson et al. 1999, Baumont et al. 2002, Heit et al. 2007. Several of these studies concluded that the Brazilian lithosphere has been underthrust westward beneath the Eastern Cordillera, but not beneath the Altiplano (Myers et al. 1998. ...
... The modern day topography (Figure 4) of the Central Andean Plateau is characterized by ∼5-6 km peak elevations in the Western Cordillera magmatic arc and Eastern Cordillera fold-thrust belt, whereas the Altiplano basin stands at ∼4 km. Quantitative paleoelevation estimates of the spatial and temporal evolution of the Central Andean paleotopography have been illuminated through multiple studies (see Figure 1 for locations and Supplemental Table 1 for paleoelevation estimates), on the basis of (a) reconstructions of the stable isotopic composition of paleometeoric water from δ 18 O in sedimentary carbonates and fossil teeth, as well as δD from volcanic glass and leaf waxes Bershaw et al. 2010;Leier et al. 2013;Saylor & Horton 2014;Kar et al. 2016); (b) paleotemperature estimates from 47 of sedimentary carbonates (Garzione et al. , 2014Ghosh et al. 2006;Leier et al. 2013;Kar et al. 2016); (c) leaf physiognomy paleotemperature estimates and pollen (Gregory-Wodzicki et al. 1998, 2000Graham et al. 2001;Kar et al. 2016); (d ) genetic divergence of a potato parasite nematode (Picard et al. 2008); and (e) paleosurfaces and their incision histories (Kennan et al. 1997;Barke & Lamb 2006;Hoke et al. 2007;Schildgen et al. 2007Schildgen et al. , 2009aThouret et al. 2007;Jeffery et al. 2013;Whipple & Gasparini 2014;Fox et al. 2015) (Supplemental Table 1). Using all of these constraints, the reconstructed paleotopography history (Figure 4) from different locations in the Western Cordillera, Eastern Cordillera, and Altiplano basin reveals that the Cenozoic evolution of the Central Andean Plateau is marked by considerable variation in the nature and timing of surface uplift, both along and perpendicular to the strike of the plateau. ...
... The principal challenge to correcting paleoelevation estimates for climate change associated with surface uplift is that the surface elevation is unknown. Recent studies of paleoelevation proxies attempt to address this challenge by applying climate change "corrections" associated with the effects of surface uplift on climate (Leier et al. 2013, Garzione et al. 2014, Kar et al. 2016) on the basis of modeling studies (Ehlers & Poulsen 2009 Thouret et al. 2007, Schildgen et al. 2009b, Fox et al. 2015Kennan et al. 1997, Barke & Lamb 2006 Jordan et al. 2010 Kar et al. 2016Saylor & Horton 2014Leier et al. 2013Graham et al. 2001Picard et al. 2008Bershaw et al. 2010Gregory-Wodzicki et al. 1998, Gregory-Wodzicki 2002Garzione et al. 2006, Ghosh et al. 2006Garzione et al. 2014 Average modern topography Paleotopography Paleotopography from previous time period Simulated responses to Andean elevations for three cases with elevations of 100%, 80%, and 40% of modern elevation. Mean-annual (a) amount weighted precipitation δ 18 O ( ), (b) precipitation (cm/day), (c) surface temperature ( • C), and (d ) elevation (m). ...
Current end-member models for the geodynamic evolution of orogenic plateaus predict (a) slow and steady rise during crustal shortening and ablative subduction (i.e., continuous removal) of the lower lithosphere or (b) rapid surface uplift following shortening, which is associated with punctuated removal of dense lower lithosphere and/or lower crustal flow. This review integrates results from recent studies of the modern lithospheric structure, geologic evolution, and surface uplift history of the Central Andean Plateau to evaluate the geodynamic processes involved in forming it. Comparison of the timing, magnitude, and distribution of shortening and surface uplift, in combination with other geologic evidence, highlights the pulsed nature of plateau growth. We discuss specific regions and time periods that show evidence for end-member geodynamic processes, including middle– late Miocene surface uplift of the southern Eastern Cordillera and Altiplano associated with shortening and ablative subduction, latest Oligocene– early Miocene and late Miocene–early Pliocene punctuated removal of dense lower lithosphere in the Eastern Cordillera and Altiplano, and late Miocene– early Pliocene crustal flow in the central and northern Altiplano. Expected final online publication date for the Annual Review of Earth and Planetary Sciences Volume 45 is May 30, 2017. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
... Divergence times estimated for Geositta by Derryberry et al. (2011) strengthen the hypothesis that orogenic events promoted diversification of the group. That is, newer species tend to occupy the northern central part of the Andes (e.g., G. saxicolina), and the southern central portion is occupied by the oldest species (Picard et al. 2008;Garzione et al. 2008), matching the temporal pattern of emergence of the Andes (Picard et al. 2008). Chaves et al. (2011) found a strong influence of Andean uplift in the diversification of the hummingbirds, with Miocene divergence related to progenitor events in the southern part of Andes. ...
... Divergence times estimated for Geositta by Derryberry et al. (2011) strengthen the hypothesis that orogenic events promoted diversification of the group. That is, newer species tend to occupy the northern central part of the Andes (e.g., G. saxicolina), and the southern central portion is occupied by the oldest species (Picard et al. 2008;Garzione et al. 2008), matching the temporal pattern of emergence of the Andes (Picard et al. 2008). Chaves et al. (2011) found a strong influence of Andean uplift in the diversification of the hummingbirds, with Miocene divergence related to progenitor events in the southern part of Andes. ...
... G. saxicolina) showed divergence times coincident with the separation between the southern and northern parts of the central Andes (respectively, areas D and E in this work; Hoorn et al. 2010). This divergence is particularly interesting as their split is coincident in time with the uplift of the Abancay segment in Peru, showing a divergence pattern similar to the history of Globodera pallida for this region (Picard et al. 2008). ...
Diverse historical and ecological factors deter-mine and drive diversification of vertebrate lineages. His-torical factors (e.g., orogenic movements) are expected toact on coarser spatial and temporal scales than contempo-rary ecological factors (e.g., climate and biotic interac-tions). However, distinctions between such scales remainarbitrary, and yet are important to understanding whichfactors acted in the emergence of new species. We inferredancestral states for climatic niches on ecological scales,and ancestral area reconstructions for the genusGeosittaondeeper time scales. Ecological niches did not overlap morebetween sister species than among more distant relatives,and rather pointed to a plastic scenario for climatic diver-sification ofGeosittarather than niche conservatism.Events temporally associated with the formation of theAndes (Miocene) seem to explain most of the diversifica-tion. In sum, climatic factors may not have had a greatinfluence in the diversification ofGeositta, at least in thecontext of Pleistocene climate fluctuations.
... Divergence times estimated for Geositta by Derryberry et al. (2011) strengthen the hypothesis that orogenic events promoted diversification of the group. That is, newer species tend to occupy the northern central part of the Andes (e.g., G. saxicolina), and the southern central portion is occupied by the oldest species (Picard et al. 2008;Garzione et al. 2008), matching the temporal pattern of emergence of the Andes (Picard et al. 2008). Chaves et al. (2011) found a strong influence of Andean uplift in the diversification of the hummingbirds, with Miocene divergence related to progenitor events in the southern part of Andes. ...
... Divergence times estimated for Geositta by Derryberry et al. (2011) strengthen the hypothesis that orogenic events promoted diversification of the group. That is, newer species tend to occupy the northern central part of the Andes (e.g., G. saxicolina), and the southern central portion is occupied by the oldest species (Picard et al. 2008;Garzione et al. 2008), matching the temporal pattern of emergence of the Andes (Picard et al. 2008). Chaves et al. (2011) found a strong influence of Andean uplift in the diversification of the hummingbirds, with Miocene divergence related to progenitor events in the southern part of Andes. ...
... G. saxicolina) showed divergence times coincident with the separation between the southern and northern parts of the central Andes (respectively, areas D and E in this work; Hoorn et al. 2010). This divergence is particularly interesting as their split is coincident in time with the uplift of the Abancay segment in Peru, showing a divergence pattern similar to the history of Globodera pallida for this region (Picard et al. 2008). ...
Diverse historical and ecological factors determine
and drive diversification of vertebrate lineages. Historical
factors (e.g., orogenic movements) are expected to
act on coarser spatial and temporal scales than contemporary
ecological factors (e.g., climate and biotic interactions).
However, distinctions between such scales remain
arbitrary, and yet are important to understanding which
factors acted in the emergence of new species. We inferred
ancestral states for climatic niches on ecological scales,
and ancestral area reconstructions for the genus Geositta on
deeper time scales. Ecological niches did not overlap more
between sister species than among more distant relatives,
and rather pointed to a plastic scenario for climatic diversification
of Geositta rather than niche conservatism.
Events temporally associated with the formation of the
Andes (Miocene) seem to explain most of the diversification.
In sum, climatic factors may not have had a great
influence in the diversification of Geositta, at least in the
context of Pleistocene climate fluctuations.
... Interestingly, such a relationship is now deemed robust enough to use it to define the time a mountain was built (e.g. Picard et al. 2008), and provide a welcome source of independent data to geologists. Most modern mountain ranges uplifted during the last 30 Ma, but more detailed chronologies are elusive, even for the Tibetan plateau (e.g. ...
... Further, the phylogenetic archive in return constitutes an unparalleled database to quantify the timing of the changing physical world, for which the geological archive is often silent (e.g. Picard et al. 2008). Of course, phylogenetic data are a Pandora box and also come with some caveats (e.g. ...
Deciphering the physical causes of evolution of the biosphere as we know it today, as well as in the past, from the phylogenetic and fossil archive, within the not-so-serene geological history, is the overarching objective of geophysical biogeography. Interactions between the physical environment and the biosphere are reflected in the common classifications used by biogeographers and conservationists: realms, biomes and ecoregions. The biota responds to the current physical environment, as well as to the precursor conditions: the current biota, at a given location, can be viewed as the time integral of the interactions between the biosphere and its geophysical environment. Like the horizontal displacement of continents, regional ups and downs of the Earth's surface not only reshape the physiography on which biota evolve, but also its continental scale decorum, that is, the climate, which may facilitate or hamper dispersal routes.
... In the Andes, mountain building occurred during the late Cenozoic (Table 3). In the Western Cordillera, δD-based paleoelevation and molecular phylogenetic studies suggest that southwestern Peru reached elevations of ∼2,000-4,500 during ∼15-10 Ma (Picard et al., 2008;Sundell et al., 2019). Table 3). ...
... Table 3). In the northern and southern Andes, δ 18 O, paleotemperature-based paleoelevations, and phylogenetic studies show that these regions were close to modern elevations during the latest Miocene-Pliocene (e.g., Picard et al., 2008; Table 3). ...
During the Miocene, major global cooling occurred during two intervals: the middle Miocene (∼14–13 Ma) and the late Miocene (∼7‐6 Ma). The Antarctic Ice Sheet expanded substantially at ∼14–13 Ma, and glaciation in the Northern Hemisphere was initiated at ∼7–6 Ma. Although the causes of these two global cooling events remain unclear, paleoclimate modeling provides an important approach for investigating the mechanisms. However, paleoclimate modeling relies on paleogeographic boundary conditions, and many uncertainties remain regarding the land–sea distribution, topography, and bathymetry of the Miocene; specifically, previous published paleogeographic reconstructions for the middle and late Miocene show several discrepancies with each other. Here, we present two new sets of global topographic and bathymetric boundary conditions for the middle Miocene (∼14 Ma) and late Miocene (∼6 Ma). Our new reconstructions use a published plate kinematics model, oceanic lithospheric paleo‐ages, and oceanic sediment thicknesses and incorporate global fossil records, stratigraphy, lithofacies, paleoenvironment, and paleoelevation data. With these data, we further constrain the conditions of several important intercontinental and marginal seas surrounding Eurasia and the Arctic, the depth of major seaways in tropical latitudes and middle‐high latitudes of the Northern Hemisphere, and global paleotopography, especially that of the Tibetan Plateau and the Andes.
... Il sera alors montré que les populations péruviennes possèdent une diversité génétique supérieure à celle observée pour les populations européennes (Bendezu et al., 1998). Suite à un échantillonnage conséquent effectué au Pérou, la structure des populations de G. pallida ainsi que l'aire d'origine de l'espèce G. pallida, où la diversité Picard et al. (2007Picard et al. ( , 2008. Répartition des différents clades génétiques observés chez G. pallida au Pérou et relations phylogénétiques. ...
... pallida type chilien », dont le cas est discuté plus bas, le groupe le plus divergent est le groupe nommé groupe 4. Les différents groupes (1a, 1b, 2, 3 et 4) sont identifiés grâce aux analyses basées sur les fréquences alléliques issues de génotypage à l'aide des marqueurs microsatellites. Le groupe 4 se situe dans le nord de notre zone d'étude, c'est-à-dire dans le sud de l'aire de répartition du clade 4. La totalité des populations du groupe 4 présente un Picard et al. (2007Picard et al. ( , 2008 (Picard et al., 2007Grenier et al., 2010). Les fortes disparités entre clades du nord et du sud du Pérou ont déjà été relevées. ...
Les nématodes à kyste du genre Globodera sont parmi les phytoparasites les plus étudiés de par l’impact économique qu’ils peuvent engendrer sur les productions agricoles. Originaire des hauts plateaux de la cordillère des Andes ce genre aurait été importé en Europe à la fin du XIX siècle. L’existence d’un complexe d’espèce cryptique chez G. pallida, nématode phytoparasites d’importance au sein du genre, est questionnée. La révision taxonomique de cette espèce peut avoir des conséquences fortes en termes d’épidémiologie, d’évaluation et de gestion des risques. Durant ce travail une approche de taxonomie intégrative impliquant trois champs disciplinaires, génétique, morphométrique et biologique, a été développée sur un panel de populations sud-américaines pour délimiter de nouvelles frontières au sein de cette espèce. L’exploration de la diversité génétique a permis de révéler l’exitence de deux groupes fortement distants de G. pallidaCette étude questionne aussi les processus impliqués dans cette divergence qui semblent distincts pour ces deux groupes. L’existence d’une différenciation morphologique a été observée grâce à un outil d’analyse d’image automatisé créé spécifiquement pour ce travail. Le développement de l’outil constitue une approche novatrice pour l’étude de la morphométrie dans ce genre et plus généralement chez les nématodes. Cette différenciation s’appuie sur l’intégration combinée de trois métriques adaptées à la morphométrie automatisée. Enfin, l’étude de la capacité de ces entités à se développer aux dépens de certaines plantes a elle aussi rapporté des
... Nonetheless, it is likely that diversification of the tribe was promoted by the uplift of the eastern cordillera of the central Andes starting in the Miocene (Garzione et al., 2008;Antonelli et al., 2009;Luebert and Weigend, 2014), which might account for the predominance of vicariant events in the internal nodes of the Eustephieae phylogeny (Figure 10). That uplift in Andean Peru may have proceeded from the south to the north (Picard et al., 2008) probably influenced the diversification timing of the tribe relative to the other groups in the Andean clade. ...
... Though the exact timing and rate of Andean uplift remains controversial (Garzione et al., 2008;Picard et al., 2008;Antonelli et al., 2009;Luebert and Weigend, 2014;Mutke et al., 2014), there is greater consensus on the ways in which the vast and heterogeneous orogenic chain has directly affected plant diversification (Simpson, 1975(Simpson, , 1983Antonelli and Sanmartín, 2011;Hoorn et al., 2013;Luebert and Weigend, 2014). The main classes of effects are (1) creation of new high elevation habitats, (2) providing barriers that result in vicariance (Figure 10), (3) providing a bi-directional north-south migration corridor, and (4) generating new environments for colonization outside of the Andes. ...
One of the two major clades of the endemic American Amaryllidaceae subfam. Amaryllidoideae constitutes the tetraploid-derived (n = 23) Andean-centered tribes, most of which have 46 chromosomes. Despite progress in resolving phylogenetic relationships of the group with plastid and nrDNA, certain subclades were poorly resolved or weakly supported in those previous studies. Sequence capture using anchored hybrid enrichment was employed across 95 species of the clade along with five outgroups and generated sequences of 524 nuclear genes and a partial plastome. Maximum likelihood phylogenetic analyses were conducted on concatenated supermatrices, and coalescent-based species tree analyses were run on the gene trees, followed by hybridization network, age diversification and biogeographic analyses. The four tribes Clinantheae, Eucharideae, Eustephieae, and Hymenocallideae (sister to Clinantheae) are resolved in all analyses with > 90 and mostly 100% support, as are almost all genera within them. Nuclear gene supermatrix and species tree results were largely in concordance; however, some instances of cytonuclear discordance were evident. Hybridization network analysis identified significant reticulation in Clinanthus, Hymenocallis, Stenomesson and the subclade of Eucharideae comprising Eucharis, Caliphruria, and Urceolina. Our data support a previous treatment of the latter as a single genus, Urceolina, with the addition of Eucrosia dodsonii. Biogeographic analysis and penalized likelihood age estimation suggests an origin in the Cauca, Desert and Puna Neotropical bioprovinces for the complex in the mid-Oligocene, with more dispersals than vicariances in its history, but no extinctions. Hymenocallis represents the only instance of long-distance vicariance from the tropical Andean origin of its tribe Hymenocallideae. The absence of extinctions correlates with the lack of diversification rate shifts within the clade. The Eucharideae experienced a sudden lineage radiation ca. 10 Mya. We tie much of the divergences in the Andean-centered lineages to the rise of Frontiers in Plant Science | www.frontiersin.org 1 November 2020 | Volume 11 | Article 582422 Meerow et al. Andean Amaryllidaceae the Andes, and suggest that the Amotape-Huancabamba Zone functioned as both a corridor (dispersal) and a barrier to migration (vicariance). Several taxonomic changes are made. This is the largest DNA sequence data set to be applied within Amaryllidaceae to date.
... Alignments with the ITS rRNA, COI and cytb gene sequences were created using ClustalX 1.83 (Chenna et al., 2003) with default parameters. New sequences were aligned with corresponding published gene sequences (Ferris et al., 1995(Ferris et al., , 1999Blok et al., 1998;Subbotin et al., 2000Subbotin et al., , 2001Subbotin et al., , 2011Sabo et al., 2002;Manduric & Andersson, 2004;Širca & Urek, 2004;Picard et al., 2007Picard et al., , 2008Plantard et al., 2008;Pylypenko et al., 2008;Grenier et al., 2010;Madani et al., 2010;Skantar et al., 2011;Geric Stare et al., 2013;Lax et al., 2014;Chitambo et al., 2019 and others). Several alignments were created: i) ITS rRNA gene alignment containing only reference sequences of each Globodera species; ii) ITS rRNA gene alignment containing all available sequences of Globodera; iii) COI gene alignment containing sequences of all studied samples; iv) COI gene sequence alignment containing reference haplotype sequences for all Globodera species; v) cytb gene alignment containing sequences of all studied samples; vi) cytb gene sequence alignment containing reference haplotype sequences for all Globodera species; and vii) several COI and cytb gene alignments containing sequences of certain species. ...
... Stone (1979) suggested that Globodera may have appeared in Gondwanaland, remaining on the part of the supercontinent which became South America while the ancestors of European species were carried northwards when fragments of Gondwanaland encountered Laurasia. This hypothesis was partly supported by Picard et al. (2008) who considered the age of the Cactodera − (Punctodera + Globodera) divergence to be close to the Heteroderinae − Punctoderinae divergence, which might have occurred after separation of Laurasia and Gondwana,i.e., Mya. The divergence of the South American and Laurasian Globodera lineages was considered to have occurred between 80 and 60 Mya after the break of a temporary connection between North and South America in the Palaeocene. ...
Globodera presently contains 13 valid and three as yet undescribed species. Three species, G. rostochiensis, G. pallida and G. ellingtonae, the potato cyst nematodes (PCN), cause significant economic losses on potatoes around the world. In our study we provide comprehensive phylogenetic analyses of 455 ITS rRNA, 219 COI and 164 cytb gene sequences of 11 valid and two undescribed species of Globodera using Bayesian inference, maximum likelihood and statistical parsimony. New 205 COI, 116 cytb and 21 ITS rRNA gene sequences were obtained from 148 populations of these species collected from 23 countries. The phylogenetic analysis revealed that Globodera displayed two main clades in the trees: i) Globodera from South and North America parasitising plants from Solanaceae; and ii) Globodera from Africa, Europe, Asia and New Zealand parasitising plants from Asteraceae and other families. Based on the results of phylogeographical analysis and age estimation of clades with a molecular clock approach, it is hypothesised that Globodera species originated and diversified from several centres of speciation located in mountain regions and then dispersed across the world from these regions during the Pleistocene. High genetic diversity of Bolivian populations of G. rostochiensis was observed for both mtDNA genes. Analysis of phylogenetic relationships of G. pallida and G. rostochiensis populations revealed incongruence in topology between networks inferred from mtDNA genes, which might be an indication of possible recombination and selective introgression events through gene flow between previously isolated populations. This puts some limitations on the use of the mtDNA marker as universal DNA barcoding identifier for PCN. Globodera bravoae syn. n. is proposed as a junior synonym of G. mexicana.
... The cuticle piece (terminal pattern) was cleared in Euparal essence and mounted in a drop of Euparal on a glass slide. The J2 and males were fixed in FPG (Netscher & Seinhorst, 1969), dehydrated to anhydrous glycerin by using the rapid Seinhorst method (Seinhorst, 1959) and permanently mounted in anhydrous glycerin on glass slides. Females were placed in cold lactophenol and incubated at 40°C for 3 days. ...
... Since it was previously established that this isolate is included in a clade of Globodera species from Europe, Asia and New Zealand that parasitise non-solanaceous plants (Knoetze & Swart, 2014), the ITS-rDNA sequence obtained was aligned with all the available sequences from this clade as well as representatives of the other major Globodera species (Ferris et al., 1999;Subbotin et al., 2001Subbotin et al., , 2011Sabo et al., 2002;Tanha Maafi et al., 2003;Manduric & Andersson, 2004;Sirca & Urek, 2004;Uehara et al., 2005;Skantar et al., 2007;Sturhan et al., 2007;Picard et al., 2008;Grenier et al., 2010;Madani et al., 2010;Handoo et al., 2012). Punctodera punctata (Thorne, 1928) Mulvey & Stone, 1976 and Betulodera betulae (Hirschmann & Riggs, 1969) Sturhan, 2002 was used as outgroup taxa. ...
A new cyst nematode, herein described as Globodera agulhasensis n. sp., was found parasitising Senecio burchelli in the Western Cape Province, South Africa. Second-stage juveniles are characterised by a well developed stylet of 23.5 (22.5-24.8) μm with rounded to anteriorly flattened knobs. The dorsal pharyngeal gland outlet is 4.4 (3.5-6.5) μm posterior to the stylet knobs. The tail is 56 (49-64) μm long and the length of the hyaline region is 25 (19-29) μm. The cysts are characterised by their ovate to spherical shape, short neck, the presence of subcuticular punctations over the entire body and the absence of bullae or vulval bodies. Six to 12 cuticular ridges/lines are present on the outer surface of the cyst between the anus and vulval basin. Granek’s ratio is 1.7 (1.0-3.0), the vulval basin diam. 17.6 (11.7-26.1) μm and the distance between vulval basin and anus is 28.6 (19.1-47.0) μm. Males have a stylet length of 26.1 (24.4-27.7) μm and spicule length of 30.3 (27.2-33.8) μm with a rounded tip. Females have a stylet length of 22.1 (19.0-24.4) μm, a large median bulb almost filling the body diam., and a short vulval slit 4.2 (3.2-6.6) μm long. Phylogenetic relationships of G. agulhasensis n. sp. with other species of the genus, inferred from ITS-rRNA sequences by using the neighbour-joining (NJ), maximum likelihood (ML) and maximum parsimony method (MP), indicate that G. agulhasensis n. sp. is included in the clade of Globodera sp. that parasitise non-solanaceous plants, forming a monophyletic group with unidentified Globodera spp. from Portugal, G. millefolii and G. artemisiae. For diagnostic purposes, three restriction enzymes, Hpy8I, RsaI and XceI were selected as being able to discriminate between G. agulhasensis n. sp. and other Globodera spp. present in South Africa.
... 20-16 Ma (S ebrier et al. 1988;Leier et al. 2013;Saylor & Horton 2014), and it has been suggested that cloud forests originated in this area around 20-18 Ma . During the Early Miocene, in northern Peru, the western cordillera was lower that southern ranges (Picard et al. 2008), but it attained locally 3 km elevations around 15 Ma (Margirier et al. 2015). Thus, the divergence of M. sulkowskyi group was possible in either the southern Central Andes or the northern western cordillera. ...
... From a geological point of view, the concept of a progressive, general south-tonorth uplift is an oversimplified view of a much more complex reality ). In the Central Andes, palaeo-elevation histories differ not only between the south and the north, but also between the western and the eastern cordilleras, notably in northern Peru (Picard et al. 2008;Eude et al. 2015;Margirier et al. 2015). The idea that the Northern Andes, as a whole, uplifted later than the Central Andes, as suggested by Doan (2003), and often admitted by other authors, is not supported by geological studies that also demonstrate that the timing of palaeo-elevation differed between the three Colombian Cordilleras (Restrepo- Moreno et al. 2009). ...
The monophyletic Morpho sulkowskyi butterfly group, endemic of Andean cloud forests, was studied to test the respective contributions of Mio-Pliocene intense uplift period and Pleistocene glacial cycles on Andean biodiversity. We sampled nine taxa covering the whole geographical range of the group. Two mitochondrial and two nuclear genes were analysed using a Bayesian method. We established a dated phylogeny of the group using a relaxed clock method and a wide-outgroup approach. To discriminate between two hypotheses, we used a biogeographical probabilistic method. Results suggest that the ancestor of the M. sulkowskyi group originated during the Middle–Late Miocene uplift of the Eastern Cordillera in northern Peru. Biogeographical inference suggests that the M. sulkowskyi and Morpho lympharis clades diverged in the northern Peruvian Andes. The subsequent divergences, from the Late Miocene to the Late Pliocene, should have resulted from a dispersal towards the Northern Andes (M. sulkowskyi clade), after the closure of the West Andean Portal separating the Central and Northern Andes, and a southwards dispersal along the Peruvian and Bolivian Eastern Cordilleras (M. lympharis clade). Only a few divergences occurred at the very end of the Pliocene or during the Pleistocene, a period when the more recent uplifts interfered with Pleistocene glacial cycles.
... Currently, populations of U. bakeri are distributed along the eastern versant of the Andes (Mantilla-Meluk, 2014) (Fig. 4), separated from the southernmost records of U. davisi in Middle America by more than 2000 km and uninhabitable highland ecosystems with elevations greather than 3000 m in some regions of the northern Andes (Fig. 4). Our analysis pointed to a relatively recent split between U. bakeri and U. davisi 4-1.4 Mya, implying an expansion of U. bakeri populations, into the piedmonts of the eastern versant of the Andes, a process that occurred while the major uplift of the system was already underway (Gregory-Wodzicki, 2000;Garver et al., 2005;Picard et al., 2008). These results encouraged us to search for potential routes of a cis-Andean connection, involving the lowest elevation passes in the northern portion of the Andes. ...
... In our Bayesian phylogeny all samples of U. b. thomasi grouped in a single clade, but our Minimum Spanning Tree (Appendix B) shows a close relationship between the U. b. thomasi specimen (TK22594), and the U. davisi group. The above-mentioned findings open the possibility for morphological and maybe physiological adaptations as the limiting factors determining the cis-Andean gene flow, in a dispersal processes that occured after the major northern Andes uplifting events were already in progress (6-2 million years ago; Gregory-Wodzicki, 2000;Garver et al., 2005;Picard et al., 2008). ...
Geological events, such as the rising of the Andes and the completion of the Isthmus of Panama (linking North and South America) have induced the end or the beginning of geographical barriers, as well as the establishment of environmental conditions that can limit or extend species’ distribution. These events seem to be related with the diversification of the tent-making bats, genus Uroderma (Chiroptera: Phyllostomidae). In the present study, different methodological approaches were applied to reconstruct the evolutionary history of Uroderma, through the estimation of a diversification time-frame, dispersal routes, and to determine the origin of its hybrid zone in Central America. We analyzed sequences from the mitochondrial gene Cytochrome b (Cyt-b). Phylogenetic relationships between species were estimated using maximum parsimony and Bayesian inference approaches, we reconstructed the biogeographic history of the genus, divergence times for the splitting events were determined, and demographic history of species involved in the hybrid zone (U. convexum and U. davisi) was estimated. The Central Andes was identified as a center of diversification for Uroderma during the Late Miocene (5.8–3.7 Mya), and Central America for the most recent common ancestor of U. convexum and U. bakeri + U. davisi, which migrated though a stepping stone model before the completion of the Isthmus of Panama (3.8 Mya; 95%, Higuest Posterior Distribution [HPD] 4.6–2.9 Mya); Central America was recovered as the distribution of MRCA of U. bakeri and U. davisi, and its split dated to the late Pliocene – Quaternary (2.8 Mya, 4–1.4 Mya). The diversification of Uroderma is a series of recent events that involved dispersal episodes across extreme barriers (Panama Canal and the highlands of the northern Andes), with potential for population expansion and retreats, explaining the current distribution of the species.
... Topographic barriers are frequently associated with phenotypic and genetic discontinuities in Andean species, providing evidence for the importance of physical isolation in Andean diversification (e.g., [20][21][22]). However, if physical isolation across topographic barriers were the sole driver of Andean speciation, species-level differences would be expected to accumulate via neutral processes. ...
... Geographic isolation promotes genetic divergence Phylogenetic, network, and AMOVA analyses all point to an important role for topographic barriers in structuring genetic diversity in Metallura tyrianthina, a result consistent with studies of the Genus Metallura as a whole [51,94] and many other Andean taxa (e.g. [9,21,40,[95][96][97]). We found the North Peru Low, Apurímac Valley and high Andean ridges to be associated with genetic structure in M. tyrianthina as in many other taxa [20,97,98]. ...
Background:
The ridges and valleys of the Andes create physical barriers that limit animal dispersal and cause deterministic local variation in rainfall. This has resulted in physical isolation of animal populations and variation in habitats, each of which has likely contributed to the evolution of high species diversity in the region. However, the relative influences of geographic isolation, ecoclimatic conditions, and their potential interactions remain poorly understood. To address this, we compared patterns of genetic and morphological diversity in Peruvian populations of the hummingbird Metallura tyrianthina.
Results:
Phylogenetic and variation partitioning analyses showed that geographic isolation rather than climatic dissimilarity explained the greatest proportion of genetic variance. In contrast, bill length variation was explained by climatic seasonality, but not by genetic divergence. We found that mutation-scaled migration rate (m) between persistently humid and semi-humid environments was nearly 20 times higher when the habitats were contiguous (m = 39.9) than when separated by a barrier, the Cordillera de Vilcanota (m = 2.1). Moreover, the population experiencing more gene flow exhibited a lesser degree of bill length divergence despite similar differences in climate.
Conclusions:
Geographic isolation is necessary for genetic divergence. Ecological differences, represented here by climate characteristics, are necessary for functional divergence. Gene flow appears to hinder the evolution of functional traits toward local adaptive optima. This suggests that functional diversification requires geographic isolation followed or accompanied by a shift in ecological conditions. Andean topography causes both isolation and climatic variation, underscoring its dual role in biotic diversification.
... Rapid surface uplift and the generation of multiple km of elevation between 25 and 10 Ma in the Central Andes has been documented by Δ47 clumped isotopes and δ 18 O analysis of soil carbonates, pollen assemblages and leaf wax lipids 16,61 , in addition to the already moderate elevation (i.e., 1.5-2 km) suggested for the late Oligocene to Miocene based on leaf physiognomy 62 and phylogenetics 15 , fossil flora 63 , and structural reconstruction of regionally extensive ignimbrites along the Western Cordillera and western Central Andean Pacific slope 64 . In finer detail, Saylor and Horton 17 suggested the attainment of high topography in the northern Central Andean region may have taken place in a non-uniform fashion 38,59 , wherein the Western Cordillera experienced faster and earlier surface uplift than the neighboring Altiplano region. ...
The high flux magmatism, crustal shortening/extension and plateau formation in Cordilleran orogenic systems have been explained by removal of lithosphere (lower crust and the sub-arc mantle lithosphere) that develops beneath the magmatic arc and hinterland regions. However, the primary role of this process driving surface uplift, and crustal deformation is not well understood. Here, reconciling geodynamic model predictions with lithospheric structure and paleoelevation estimates, we suggest that viscous drip-type lithospheric removal from beneath the Central (Peruvian) Andes can explain several tectonic features: (1) “double humped” shaped/axisymmetric topographic profile and rapid surface rise (up to 1.2 km in ~ 4.31 Myrs); (2) thicker crust associated with the lower surface elevation of the Altiplano plateau (Lake Titicaca region) (negative residual topography) and higher topography and thinner crust of Western and Eastern Cordilleras (positive residual topography); and (3) faster wave speed (colder)/sub-Moho anomaly underlying the Altiplano, surrounded by slower speed anomalies on both western arc-forearc areas and parts of the eastern Cordillera and Sub-Andes. Our results emphasize the important role of lithospheric drip and associated mantle dynamics in the transient evolution of Andean orogeny controlling surface uplift and crustal flow and thickening.
... Late Cenozoic surface uplift in the northern CAP Altiplano may have been partly decoupled from crustal thickening, in contrast to the earlier elevation gain in the western CAP margin (Figure 4h) and Puna region of the southern CAP (Canavan et al., 2014;Quade et al., 2015). For example, phylochronologic analysis of potato parasite nematodes suggests the maximum paleoelevation of the northern CAP between 25 and 18 Ma was no more than half of its current elevation (Picard et al., 2008). Gregory-Wodzicki (2000) similarly required a ∼2 km elevation maximum by early Miocene time based on leaf physiognomy, although this study disregards climatic effects. ...
Plain Language Summary
Detailed relationships between crustal thickening, surface uplift, and climate remain unresolved. Although most mountains seem to be in isostatic equilibrium today, there is an imperfect correlation between elevation and crustal thickness in the modern continental lithosphere globally. We report trace element geochemical data of zircons extracted from volcanic rocks, sandstones, and modern river sediments collected in the northern Central Andean Plateau. Our analysis suggests that crustal thickness significantly increased from 80 to 55 Ma and from 35 Ma to present. The magmatic record between these two periods is obscured because the subducting slab shallowed, causing a decrease in magmatic activity; despite this, crustal thickening continued due to crustal shortening. The ∼80 Myr history of crustal shortening correlates with an early phase of surface uplift on the western side of the orogenic system, but contrasts with the main phase of plateau uplift and establishment of hyperaridity along the Pacific coast.
... A general trend of increasingly older divergence time estimates moving southward along the Andes, consistent with Andean uplift occurring from south to north, has been previously reported (Luebert and Weigend 2014). Our findings of greater phylogenetic diversity in southern Andean alpine communities are consistent with this reported general trend as well as some clade-specific specific phylogeographic studies on diversification along the Andes (Picard et al. 2008). When alpine and montane species were combined, the southern Andes still showed higher levels of phylogenetic diversity compared to other Andean sites (Supplemental Fig. S7); however, the trend was not as strong. ...
Although mountainous habitats contribute substantially to global biodiversity, comparatively little is known about biogeographic patterns of distributions of alpine species across multiple mountain ranges. Here, we present a detailed analysis of the distributions and phylogenetic affinities of alpine seed plant lineages across North, Central, and South American mountain systems. Using a large dataset that characterizes the elevational niches of American seed plants in a continuously valued way, we related the proportion of alpine habitat occupied by plant lineages to their biogeographic distributions at a regional scale and place these results in a phylogenetic context. We found alpine species diversity to be greatest in the central Andes and western North America, and that assemblages with lower phylogenetic diversity contained species with a greater degree of alpine specialization. In particular, near-Arctic/boreal alpine communities were characterized by low phylogenetic diversity and higher degrees of alpine specialization, whereas the opposite was observed for southern Patagonian communities. These results suggest that abiotic filtering alone in these climatically similar regions is unlikely to explain alpine community assembly. Nevertheless, the overall relative rarity of alpine specialists, and the tendency for such specialists to be most closely related to montane lineages, suggested that filtering was still an important factor in shaping alpine community structure. This work corroborates the importance of a nuanced and scale-dependent perspective on the ‘history-filtering’ debate axis, as both factors have likely contributed to modern biodiversity patterns observed in alpine plant communities across the Americas.
... There have been many phylogenetic analyses of species within the genus Globodera (e.g., [5,73,[76][77][78][79][80][81][82][83][84][85][86]). A recent study, based on a phylogenetic analysis of gene sequences of three molecular markers (455 ITS rRNA, 219 COI, and 164 cytb) of 11 valid and 2 undescribed species of Globodera [87], found that Globodera displayed two main clades in their phylogenetic trees: (i) Globodera from South and North America parasitizing plants from Solanaceae; and (ii) Globodera from Africa, Europe, Asia, and New Zealand parasitizing plants from Asteraceae and other families. ...
The scope of this paper is limited to the taxonomy, detection, and reliable morphological and molecular identification of the potato cyst nematodes (PCN) Globodera pallida and G. rostochiensis. It describes the nomenclature, hosts, life cycle, pathotypes, and symptoms of the two species. It also provides detailed instructions for soil sampling and extraction of cysts from soil. The primary focus of the paper is the presentation of accurate and effective methods to identify the two principal PCN species.
... Crustal thickening in the NW-trending region of the Bolivian Orocline has developed since~30 Ma (Picard et al. 2008;Sempere et al. 2008 and references therein). The onset of crustal thickening thus coincided with the widespread development of mafic magmatism during the Late Oligocene and earliest Miocene. ...
The Bolivian tin belt is a metallogenic province in the Eastern Cordillera of the Andes known for its Sn, W, Ag, and base metal deposits. Cassiterite, which is a major constituent in many magmatic-hydrothermal ore deposits from the Bolivian tin belt, can incorporate dozens of elements within its crystal lattice, making it a useful geological tracer mineral and also a potential host of critical elements. New U-Pb dating of cassiterite yields Late Triassic (Kellhuani deposit) and Late Oligocene to earliest Miocene (Viloco, Huanuni, and Llallagua deposits) ages. These ages confirm that Sn mineralization in the Bolivian tin belt occurred at least in two separate events during two major magmatic episodes apparently triggered by mantle upwelling, decompression melting, and basalt production promoting high heat flow into the overlying crust. The composition of studied hydrothermal cassiterite yields some geochemical trends that are attributed to its distance to the causative intrusion and/or level of emplacement. For example, cassiterite is generally enriched in Nb and Ta and yields higher Ti/Zr and Ti/Sc ratios in samples from xenothermal ore deposits located adjacent to intrusive complexes relative to shallow xenothermal and epithermal ore deposits. Therefore, these geochemical trends in cassiterite are useful tracers pointing to magmatic-hydrothermal centers. REE distribution in cassiterite was likely influenced by boiling processes, which resulted in tetrad-type irregularities. Cassiterite from the Bolivian tin belt is unattractive as a source for Nb (interquartile range [IQR] 4.84–0.037 ppm), Ta (IQR 0.0924–0.0126 ppm), and Ge (IQR 3.92–0.776 ppm). Some deposits, however, contain cassiterite relatively enriched in In (IQR 96.9–9.78 ppm, up to 1414 ppm) and Ga (IQR 92.1–3.03, up to 7437 ppm), that could constitute an attractive supplementary source for these elements in addition to sulfide minerals in the same deposits.
... 0.3 km) average elevation and is much more incised than the low-relief and internally drained Altiplano to the south (Fig. 1c). Palaeoaltimetry data (Picard et al. 2008;Sundell et al. 2019) and biodiversity records (Hoorn et al. 2010) suggest that the study area acquired its modern elevation of c. 4 km before 5 Ma. At the scale of the Central Andes, different potential uplift mechanisms have been proposed, including crustal shortening (Barnes and Ehlers 2009), lithospheric delamination (Garzione et al. 2006) and crustal flow (Husson and Sempere 2003; for a review see Garzione et al. 2017). ...
The Abancay Deflection, forming the northern edge of the Altiplano in the Peruvian Andes, is a remarkable geomorphological feature marking the along-strike segmentation of the Andes. Little is known about the timing and spatial distribution of exhumation in this area. To constrain the exhumation history of the Abancay Deflection and its drivers, we present apatite (U–Th)/He and fission-track thermochronology data from samples collected along an elevation transect at Machu Picchu. Geomorphological analysis demonstrates recent and continuing drainage reorganization recorded by the spatial distribution of the normalized steepness index ( k sn ) and normalized integrated drainage area ( χ ) parameters. Thermochronologically derived cooling rates are converted into exhumation using regionally constrained geothermal gradients between 16 and 26°C km ⁻¹ . Time–temperature inversions imply steady and slow exhumation (<0.05 km Ma ⁻¹ ) between 20 and 4 Ma, followed by rapid exhumation (>0.9 km Ma ⁻¹ ) since 4 Ma. The timing of rapid exhumation, combined with the geomorphological analysis, suggests that fluvial capture of the previously endorheic Altiplano by the Urubamba River drove recent incision and exhumation. Depending on the value of the geothermal gradient used, total exhumation since 4 Ma can be explained by river incision alone or requires additional exhumation driven by tectonics, possibly associated with movement on the Apurimac fault.
Supplementary material: Additional information is available at https://doi.org/10.6084/m9.figshare.c.5177343
... More generally, the parallel to the case of the Central American Seaway is relevant beyond the methodological aspects: while Bacon et al. (2015) took advantage of the patterns of diversification to establish the timing of a geological event, this history of Sundaland exemplifies how the geological record conversely informs on the diversification patterns. But in Sundaland also, the timing of divergence can narrow uncertainties in the timing of paleogeographic changes (e.g., Picard et al., 2008). While geomorphological data bracket subsidence rates of the Sunda shelf between 0.2 and 0.3 mm/yr, phylogeographic data arguably curtail the range to its lower end (Fig. 2a). ...
It is widely accepted that sea level changes intermittently inundated the Sunda Shelf throughout the Pleistocene, separating Java, Sumatra and Borneo from the Malay Peninsula and from each other. On this basis, the dynamics of the biodiversity hotspot of Sundaland is consistently regarded as solely contingent on glacial sea level oscillations , with interglacial highstands creating intermittent dispersal barriers between disjunct landmasses. However, recent findings on the geomorphology of the currently submerged Sunda shelf suggest that it subsided during the Pleistocene and that, over the Late Pliocene and Quaternary, is was never submerged prior to Marine Isotope Stage 11 (MIS 11, 400 ka). This would have enabled the dispersal of terrestrial organisms regardless of sea level variations until 400 ka and hampered movements thereafter, at least during interglacial periods. Existing phylogeographic data for terrestrial organisms conform to this scenario: available divergence time estimates reveal an 8-to 9-fold increase in the rate of vicariance between landmasses of Sundaland after 400 ka, corresponding to the onset of episodic flooding of the Sunda shelf. These results highlight how reconsidering the paleogeographic setting of Sundaland challenges understanding the mechanisms generating Southeast Asian biodiversity.
... The central Andes (~13° S, 28° S) started to uplift in the Eocene or Oligocene, and in the north the mountains first reached high elevations, progressively extending northwards (Gregory-Wodzicki, 2000;Picard et al., 2008). The initial uplift of the Sierra de Perijá took place in the late Oligocene (ca. 25 mya), almost simultaneously with the orogenesis of the Cordillera de Mérida and the Eastern Cordillera of Colombia (Irving, 1975). ...
Faunal structure, species relationships and distribution patterns of Pronophilina butterflies, a Neotropical montane section of the Satyrinae (Nymphalidae), of 5 isolated north Andean massifs —Cordillera de Mérida, Sierra El Tamá, Sierra Nevada de Santa Marta, Cordillera de la Costa and Sierra de Perijá— are analyzed from the island biogeography perspective. El Tamá range, a part of the “continental” Eastern Cordillera, is considered as the source area of the faunas of the Sierra de Perijá and the Cordillera de Mérida, which in turn are stepping stones for the dispersal of species to the Sierra Nevada de Santa Marta and the Cordillera de La Costa. The role of major biogeographical variables is evaluated in the process of colonization of these areas. It is conlcuded that the maximum elevation between the neighbouring ranges is the most important variable, not the distance. This is related to the fact that dispersal in this group of butterflies seems to occur by slow expansion through ecological corridors not by long distance flights. Faunal relationships between the 5 ranges and the elevational bands occupied by widespread and endemic species allow inferring the extent of vertical movements of cloud forests in the past.
... By that time the Central Andes might have reached altitudes above 2000 m as inferred from other dated phylogenies (e.g. Picard et al., 2008). Elevations exceeding 2000 m are here considered as a dispersal barrier that effectively separated both genera. ...
The Atacama Desert in western South America is considered as one of the driest places on earth, but is nevertheless characterized by surprisingly high species richness and levels of endemism. The plant genus Cristaria (Malvaceae), with ca. 21 species, is one of the most diverse genera of the Atacama Desert, while the much less diverse sister genus Lecanophora (7 species) is found east of the Andes. Here, we use DNA sequence data and divergence time estimates in order to investigate the biogeographical history of the Atacama species of Cristaria. We further investigate a possible influence of Andean uplift and the subsequent onset of hyperaridity in the Atacama Desert on diversification times in Cristaria. We sequenced three plastid markers (ndhF, trnK(matK) & rpl16) for 19 species of Cristaria and two species of Lecanophora from the Atacama Desert and Argentina, respectively. Further, we included sequences of the same plastid regions from GenBank in order to get a comprehensive dataset of Malvoideae. Phylogenetic relationships were inferred using maximum likelihood and Bayesian analyses, and divergence times were estimated with BEAST2. Our results place the monophyletic genera Cristaria and Lecanophora as sister groups in a clade sister to the rest of Malveae. The split between these two lineages (~20 Ma) correlates with Andean uplift during the early Miocene, indicating a vicariant event. During the late Miocene, two Mediterranean members of Cristaria separated from the major Atacama clade. The subsequent diversification of the latter one correlates with the onset and subsequent temporal expansion of hyperarid conditions in the Atacama Desert since the late Miocene and during the Quaternary climate oscillations.
... For example, some Andean groups show a northward progression in their phylogeny, with páramo groups deeply nested, and this is usually assumed to indicate a northward series of dispersal events (e.g. Picard et al., 2008;Sklenář et al., 2011). However, the same phylogeny is also consistent with a northward series of vicariance events in an already widespread ancestor. ...
... The tectonic and topographic evolutions of the central Andes, especially in the Peruvian Andes where the Huanzala deposit is located, have been presumed by several methods, such as paleomagnetism (Rousse et al., 2002(Rousse et al., , 2003; molecular phylogenetics (Picard et al., 2008); temperature-elevation relationships deduced from H-, O-, and C-stable isotopes (Schildgen & Hoke, 2018); and zircon fission track records (Graver et al., 2005). Graver et al. (2005) examined differences between U/Th ages and fission track ages of detrital zircon grains extracted from sedimentary rocks, including the Chimu and Carhuaz Formations at the Huayhuash Range,~20 km south of the Huanzala deposit. ...
Carbonate‐replacement polymetallic mineralization at the Huanzala deposits (9°51′S, 77°00′W) was conducted in two contrasting stages that occurred in almost the same location. Early‐stage mineralization has a relation with a granodiorite porphyry stock, whereas the late‐stage mineralization is genetically associated with quartz porphyry sills. The early stage involved low to intermediate sulfidation Cu–Zn–(Pb) mineralization associated with metasomatic skarn, and the late stage involved high to intermediate sulfidation Cu–Zn–Pb–(Mn) mineralization associated with hydrothermal alteration characterized by paragonitic sericitization. The orebodies are hosted by steeply dipping (approximately 60°NE) Lower Cretaceous carbonate rocks in a relatively narrow range of approximately 4 km in horizontal extent and less than 1 km in depth. The pathway of the early‐stage brine‐derived fluids (300–>400°C, >33 wt% NaCl equivalent) along a plot of log against 1000/T is best explained by the progressive dual decline of the value and the temperature under rock‐buffering conditions; this decline saw the pathway progress through the stability field of pyrrhotite to reach that of pyrite and promoted a decrease in FeS from 14.5 to 1.6 mol% in the sphalerite. In contrast, an explanation for the pathway of the late‐stage fluids (140–290°C, 3–13 wt% NaCl equivalent) is given by an almost isothermal decline at approximately 270°C, with passing through the stability field of pyrite–bornite to reach that of chalcopyrite, promoting an increase in FeS from 0.1 to 1.6 mol% in the sphalerite, suggesting gas‐buffering conditions. The ore formation pressure records in the fluid inclusions illustrate an approximately 2‐km erosion during the roughly 2‐Myr total lifetime of the hydrothermal system.
... Moreover, this episode of diversification is also congruent with the appearance of dry floras endemic to the Marañon Valley, which diverged from the flora of the Apurimac Valley around 5 Ma (20,22). In addition, this episode is also consistent with the estimation of the divergence of high mountain Andean population groups of Globodera pallida (a pathogen nematode of potatoes) from the northern Central Andes from populations located in the southeast Andean, which occurred around 4.5Ma (29). Based on this biological data, they suggested that the Andes of Central Peru were uplifted above 2000-2500m by the Late Miocene. ...
... Las especies actuales de Salpichroa se habrían originado hace siete millones de años, época en la cual la cordillera andina habría alcanzado elevaciones similares a las actuales (Allmendinger et al., 1997;Gregory-Wodzicki, 2000;Ehlers & Poulsen, 2009;Victor et al., 2004), pero sometida a cambios bruscos, producto de las glaciaciones (Simpson, 1975;Keel, 1984;Simpson & Todzia, 1990). El surgimiento de la cordillera de los Andes ha tenido un efecto importante en la evolución y biogeografía de las especies de Salpichroa al igual que en otros grupos taxonómicos (Gengler-Nowak, 2002;Doan, 2003;Hughes & Eastwood, 2006;Picard et al., 2008;Antonelli et al., 2009;Arakaki et al., 2011;Chaves et al., 2011;Sanín & Galeano, 2011). Por tanto, la cordillera de los Andes podría haber actuado como una barrera entre el oeste y este, y como una vía de migración entre norte y sur (Gonzáles, 2013). ...
El presente estudio brinda información sobre la diversidad y los patrones de distribución de las
especies de Salpichroa a lo largo de los Andes. De un total de 1205 colecciones de herbario estudiadas,
855 fueron georreferenciadas y analizadas, de éstas, el 99 % provienen de Perú, Ecuador y Argentina.
Se reconocen 22 especies de Salpichroa, de las cuales 19 se encuentran en el Perú, el país con mayor
número de especies de ese género; le siguen Bolivia (8), Ecuador (5), Argentina (4), Chile (3), Colombia
(2), Venezuela (2), Uruguay (1), Paraguay (1) y Brasil (1). En general, Salpichroa se distribuye entre
30° S y 37° S, con la mayor riqueza de especies entre 7° S y 17° S, en el Perú. En Perú, la mayor
concentración de especies se encuentra en el departamento de Cusco. La mayor diversidad de especies
se encuentra entre 3000-4000 m de elevación en las laderas oriental y occidental de los Andes. La
alta diversidad del género en los Andes peruanos se debe probablemente a la amplia heterogeneidad
ambiental y la diversidad de hábitats presentes en la zona.
... The Andean orogenesis and the Pleistocene glacial cycles (Imbrie, Imbrie-Moore & Lisiecki, 2011) are possible mechanisms in stimulating speciation, as shown to occur in numerous groups of animals and plants (Ribas et al., 2007;Koscinski et al., 2008;Picard, Sempere & Olivier, 2008;Antonelli et al., 2009;Elias et al., 2009;Guarnizo, Amézquita & Bermingham, 2009;Chaves, Weir & Smith, 2011;Ceccarelli et al., 2016). Vertical speciation across elevational and ecological gradients (Moritz et al., 2000;Willmott, Hall & Lamas, 2001;Hughes & Eastwood, 2006;Brumfield & Edwards, 2007), and allopatric speciation between mountains or valleys in geographically adjacent areas (Willmott et al., 2001;Brumfield & Edwards, 2007;Cigliano & Amedegnato, 2010;Särkinen et al., 2012;Pocco et al., 2013;Benham & Witt, 2016) are the two main hypotheses that attempt to explain the diversity of the Andean fauna and flora. ...
The Andes harbour an outstanding taxonomic and ecological diversity, for which several mechanisms promoting diversification, including ecological gradients and allopatric speciation, have been cited. The grasshopper genus Orotettix is an informative but challenging group to study diversification mechanisms because species in the genus are morphologically very similar, have low vagility and display local endemism over a complex topography in the Central Andes. We conducted several tests using ecological niche overlap and predictions of geographical distributions of Orotettix species on a phylogenetic framework to disentangle their speciation patterns. A multilocus molecular phylogeny was generated for Orotettix. Niche similarity tests were performed and the degree of niche overlap was estimated between species. Ecological niche models were generated to assess the realized ecological niche and potential distribution. The phylogenetic signal between the phylogenetic relatedness and niche overlap, and geographical and the environmental distances were analysed. Our findings suggest that speciation was not restricted to a single period and that species origins might have coincided with glacial-interglacial cycles of the Pleistocene. Given that we only found cases of niche conservatism for Orotettix, we infer that allopatric speciation had the primary role in its diversification. No significant phylogenetic signal was found, probably due to an island-like radiation process.
... geomorphological changes, climatic changes, etc.) that may have shaped biotic distributions (Table 1, Step 3). Patterns of speciation and biogeography across groups can be used in connection with reconstructions of landscape change to understand how physical factors have shaped those landscapes and their constituent species during assembly (Campbell et al., 2006;Badgley et al., 2008;Picard et al., 2008;Cheng et al., 2013). ...
In a recent paper, we generated a new time tree of modern birds and integrated it with biogeographic and palaeontological information to formulate a model for their biogeographic history. We postulated that modern birds originated in West Gondwanan continents, from where they dispersed around the world. Mayr suggested that our selective use of the fossil record may have biased our ancestral area reconstructions. We argue that the use of the fossil record must be selective in order to avoid the influence of its severe geographic bias: rock formations with numerous high-quality fossil birds are found only in North America and Europe. An indiscriminate use of the avian fossil record would bias any biogeographic analysis towards these two continents. Our biogeographic model is perfectly consistent with the existence of diverse fossil avifaunas in the Eocene of North America and Europe because dispersion out of South America occurred earlier, in the Palaeocene.
... Aunque la cordillera andina inició su levantamiento hace unos 100 MA, su mayor desarrollo se concentra en los últimos 25 MA. La orogénesis en los Andes tropicales presenta una propagación de sur a norte, con la parte mas antigua y ancha localizada al sur de Perú y Bolivia, donde el eje de la cordillera cambia de orientación, formando el Oroclino Andino Central (Picard et al. 2008). La parte norte de los Andes (norte de Ecuador y Colombia) alcanzo alturas elevadas solamente en el Plio-Pleistoceno. ...
El noroeste de América del Sur presenta una geografía sumamente compleja, con grandes contrastes y abruptos gradientes ecológicos. Este entorno es particularmente propicio para la diversificación biológica y ecológica, y la familia de las palmeras lo ilustra perfectamente, con 332 especies (142 endémicas) en la zona considerada, conformada por Colombia, Ecuador, Perú y Bolivia, entre las 514 especies que existen en toda América del Sur (apéndice X). La región es básicamente estructurada por un eje latitudinal, la línea ecuatorial, y un eje longitudinal, la cordillera de los Andes. La línea ecuatorial determina la transición estacional entre el hemisferio norte y el hemisferio sur y el cambio de régimen de las corrientes marinas, con profundos efectos climáticos, los cuales son a su vez reforzados por los efectos topográficos de los Andes, determinando una compartimentación del ambiente a diversas escalas. El primer nivel de compartimentación es la separación por los Andes de la región costera del océano Pacifico y de la región Amazónica. La región costera es caracterizada por uno de los gradientes climáticos mas abruptos del Mundo, con una transición de norte a sur entre el bosque pluvial del Chocó-Darién, recibiendo hasta 10 000 mm de precipitaciones anualmente y el desierto costero de Perú-Chile, donde las precipitaciones bajan virtualmente a 0 en el sector de Atacama. Entre estas dos formaciones dramáticamente contrastadas, la transición vegetacional es representada por el bosque seco tumbesino (Olson 2001), el cual alberga solamente 7 especies de palmeras (Pintaud et al. 2008). El bosque pluvial del Chocó-Darién es en cambio particularmente propicio para el desarrollo de las palmeras, una familia de planta termo-higrófila por esencia, la cual presenta una gran exuberancia en este entorno (120 especies). El bosque húmedo amazónico provee condiciones similarmente favorables para las palmeras, sobre una superficie mucho mayor a la costa Pacífica, y la familia alcanza allí su mayor diversidad (160 especies). Entre estas dos regiones bajas se ubican los Andes, donde las palmeras alcanzan 3500 m de altitud. La diversidad de las palmeras es máxima en el bosque nublado subandino (1000-1800 m) y disminuye conforme a la elevación, dejando solamente tres géneros (Ceroxylon, Geonoma y Parajubaea) por encima de los 2900 m. En total, los Andes albergan 131 especies de palmeras (Apéndice X). Evolución del entorno físico y dinámica de la especiacion
... geomorphological changes, climatic changes, etc.) that may have shaped biotic distributions (Table 1, Step 3). Patterns of speciation and biogeography across groups can be used in connection with reconstructions of landscape change to understand how physical factors have shaped those landscapes and their constituent species during assembly (Campbell et al., 2006;Badgley et al., 2008;Picard et al., 2008;Cheng et al., 2013). ...
AimWe develop a conceptual framework for integrating evolutionary history and ecological processes into studies of biotic assembly. LocationGlobal. Methods
We use theoretical and empirical examples to demonstrate that species distributions are non-random outcomes of first-order processes of biotic evolution: allopatry (isolation of populations), speciation and dispersion of biotas across landscapes. We then outline generalizable steps for integrating methods of phylogenetic and historical biogeographical analyses into studies of biotic assembly. ResultsWe present a framework that can be applied to any biotic assemblage amenable to phylogenetic and historical biogeographical analyses, can accommodate changes in spatial extent and temporal scale, and will facilitate comparison of assembly processes across biotas. Additionally, we demonstrate the utility of an historical approach for providing context to ecological influences on evolutionary processes, such as trait evolution. Main conclusionsBy focusing on reconstructing the histories of individual lineages, an historical approach to assembly analysis can reveal the timing and underlying processes guiding biotic assembly, making it possible to disentangle the roles of history and ecology in the assembly process.
... The timing of major lineage splits, in addition to the current distributions of extant species, can be used to infer the progression of these migratory steps (S1 Text Section 7.6 and S6 Fig). This south-to-north range expansion and diversification has been suggested by phylogenies of other plant and animal groups in the Central Andes [85][86][87][88][89]. More broadly, Solanum is one of the most speciose and widespread angiosperm genera, with~1,500 extant species found on all continents except Antarctica. ...
Speciation events often occur in rapid bursts of diversification, but the ecological and genetic factors that promote these radiations are still much debated. Using whole transcriptomes from all 13 species in the ecologically and reproductively diverse wild tomato clade (Solanum sect. Lycopersicon), we infer the species phylogeny and patterns of genetic diversity in this group. Despite widespread phylogenetic discordance due to the sorting of ancestral variation, we date the origin of this radiation to approximately 2.5 million years ago and find evidence for at least three sources of adaptive genetic variation that fuel diversification. First, we detect introgression both historically between early-branching lineages and recently between individual populations, at specific loci whose functions indicate likely adaptive benefits. Second, we find evidence of lineage-specific de novo evolution for many genes, including loci involved in the production of red fruit color. Finally, using a "PhyloGWAS" approach, we detect environment-specific sorting of ancestral variation among populations that come from different species but share common environmental conditions. Estimated across the whole clade, small but substantial and approximately equal fractions of the euchromatic portion of the genome are inferred to contribute to each of these three sources of adaptive genetic variation. These results indicate that multiple genetic sources can promote rapid diversification and speciation in response to new ecological opportunity, in agreement with our emerging phylogenomic understanding of the complexity of both ancient and recent species radiations.
... In the context of robust, precise date estimates and pronounced habitat fidelity, however, this approach promises spatiotemporal resolution exceeding that of traditional proxies. To date, the use of replicated lineage histories as records of palaeoenvironmental change, recently termed the 'geoecodynamic approach' [37], has been employed in a diversity of systems to gain insights into biome history [38,39], drainage evolution [40,41], episodes of orogenesis [42], palaeoclimatic changes [43] and the evolution of historical fire regimes [36,44]. Although habitat mapping has been employed to constrain timings of habitat shifts within individual lineages of Cape plants [44][45][46][47], its utility as an indicator of broad-scale palaeoenvironmental change remains underexploited. ...
In the context of molecularly-dated phylogenies, inferences informed by ancestral habitat reconstruction can yield valuable insights into the origins of biomes, palaeoenvironments and landforms. In this paper, we use dated phylogenies of 12 plant clades from the Cape Floristic Region (CFR) in southern Africa to test hypotheses of Neogene climatic and geomorphic evolution. Our combined dataset for the CFR strengthens and refines previous palaeoenvironmental reconstructions based on a sparse, mostly offshore fossil record. Our reconstructions show remarkable consistency across all 12 clades with regard to both the types of environments identified as ancestral, and the timing of shifts to alternative conditions. They reveal that Early Miocene land surfaces of the CFR were wetter than at present and were dominated by quartzitic substrata. These conditions continue to characterize the higher-elevation settings of the Cape Fold Belt, where they have fostered the persistence of ancient fynbos lineages. The Middle Miocene (13-17 Ma) saw the development of perennial to weakly-seasonal arid conditions, with the strongly seasonal rainfall regime of the west coast arising ~6.5-8 Ma. Although the Late Miocene may have seen some exposure of the underlying shale substrata, the present-day substrate diversity of the CFR lowlands was shaped by Pliocene-Pleistocene events. Particularly important was renewed erosion, following the post-African II uplift episode, and the reworking of sediments on the coastal platform as a consequence of marine transgressions and tectonic uplift. These changes facilitated adaptive radiations in some, but not all, lineages studied.
... They suggest instead that the shortening of the Andes and subsequent exhumation are much older and they propose that Andean uplift may have occurred progressively for 25 Ma. Parts of the Central Andes, indeed, may have achieved an elevation as high as 2000-2500 m in early Miocene times (Picard et al., 2008;Riquelme et al., 2003). Garzione et al. (2006) and Iaffaldano et al. (2006) propose that the growth of the Andean relief is responsible for the deceleration of the Nazca subduction rates that occurred since 10 Ma (Somoza, 1998). ...
... The Andean orogenesis and the Pleistocene glacial cycles (Imbrie, Imbrie-Moore & Lisiecki, 2011) are possible mechanisms in stimulating speciation, as shown to occur in numerous groups of animals and plants (Ribas et al., 2007;Koscinski et al., 2008;Picard, Sempere & Olivier, 2008;Antonelli et al., 2009;Elias et al., 2009;Guarnizo, Amézquita & Bermingham, 2009;Chaves, Weir & Smith, 2011;Ceccarelli et al., 2016). Vertical speciation across elevational and ecological gradients (Moritz et al., 2000;Willmott, Hall & Lamas, 2001;Hughes & Eastwood, 2006;Brumfield & Edwards, 2007), and allopatric speciation between mountains or valleys in geographically adjacent areas (Willmott et al., 2001;Brumfield & Edwards, 2007;Cigliano & Amedegnato, 2010;Särkinen et al., 2012;Pocco et al., 2013;Benham & Witt, 2016) are the two main hypotheses that attempt to explain the diversity of the Andean fauna and flora. ...
The reciprocal illumination nature of integrative taxonomy through hypothesis testing, corroboration and revision is a powerful tool for species delimitation as more than one source has to support the hypothesis of a new species. In this study, we applied an integrative taxonomy approach combining molecular and morphological data sets with distributional patterns to examine the level of differentiation between and within the grasshopper Orotettix species. Orotettix was described based on five valid species distributed in the Andes of Peru. In our study, initially a molecular‐based hypothesis was postulated and tested against morphological data and geographical patterns of distribution. Results from molecular and morphological analyses showed agreement among the species delimitation in Orotettix, and were also consistent with the geographical distribution. The analyses allowed us to delimit five new species for the genus ( O. lunatus sp. nov., O . astreptos sp. nov., O. colcaensis sp. nov., O . paucartambensis sp. nov. and O . dichrous sp. nov.) from the Eastern and Western Cordilleras of Peru. We also provide critical knowledge on the phylogenetic relationships and distribution of the genus and conduct a revision of Orotettix. © 2015 The Linnean Society of London
... Such approaches can potentially be used to unravel biogeographic histories [e.g. (Funk et al., 1995;Shaw, 1996;Juan et al., 2000;Picard et al., 2008;Wallis and Trewick, 2009)], including inferences of ancestral taxon ranges, and the timings of dispersal and vicariant events. In the case of New Zealand's species-rich G. vulgaris complex, links between earth-history and freshwater biogeography are compelling Burridge et al., 2008b). ...
... According to PICARD et al., (2008), the Peruvian populations of G. pallida exhibit a clear evolutionary pattern with deeper more ancient lineages occuring in the Andean southern Peru and shallower, younger lineages occuring progressively northwards, demonstrating that altitude in the Peruvian Andes was acquired longitudinally from south to north i.e. in the direction of decreasing orogenic volume. GRENIER et al., 2010 argued that the uplift of the Andes Mountines has triggered a variety of adaptive biotic radiations for Solanaceous plant-parasitic nematodes and has represented a key factor for the evolution and specialisation of Globodera species. ...
The general opinion about the introduction of potato in Europe is the one
regarding the direction from South America to Spain and subsequent
distribution to other continents. Some historical data point out an
alternative road. The potato spread from its place of origin to other
continents in the light of parasite-host relationship, relying on nematode
molecular data, is discussed in the present work. Biogeographic history of
potato cyst nematode populations from different continents is in congruence
with historical records. [Projekat Ministarstva nauke Republike Srbije, br.
TR 31018 i br. III 46007]
... These constraints, from a wide range of techniques, suggest a rapid pulse of 2 km of surface uplift occurred between 16 and 13 Ma in the southern Altiplano and~7 My later to the north (Gregory-Wodzicki, 2002;Garzione et al., 2006Garzione et al., , 2014Ghosh et al., 2006). In addition, Picard et al. (2008) used molecular phylogenetics of highland biotaxa to estimate that the plateau had reached heights of 2.0-2.5 km by the middle to late Miocene. However, estimates of paleoatmospheric temperatures from hydrogen isotope analysis (δD) in volcanic glass from Miocene deposits found b200 km east of the Cotahuasi-Ocoña catchment, suggest that this part of the plateau had reached its current elevation by 16 Ma (Saylor and Horton, 2014). ...
... By comparison, at latitude 33°S, the main exhumation of the equivalent basement backbone, named here the Cordillera Frontal, had started at~25 Ma, as constrained by apatite (U/Th)/He (Hoke et al., 2014). The symmetric northward decrease of shortening age from 21°S to the north has barely been assessed specifically (Picard et al., 2008), but the process of bilateral propagation in the Andean Orocline has been implied, among others, by Kley (1999), Barnes and Ehlers (2009) and Ramos (2010). Despite the large scale considered here, the along-strike propagation associated with increasing slip on localized faults, crustal-scale thrust faults in this case, appears consistent with scaling laws in elastic fracture mechanics (e.g. ...
The largest tectonic relief breaking the Earth’s surface (13 km vertically) is at the subduction margin of the Andes, which generates routinely megathrust earthquakes (Mw > 8.5) and drives the paradigmatic Andean orogen. Here we present key geologic evidence to reassess first-order features of geomorphology and tectonics across the Central Andes, where the orogen includes the Altiplano Plateau and attains its maximum integrated height and width. The Andean subduction margin has a stepped morphology dominated by the low-relief Atacama Bench, which is similar to a giant uplifted terrace, slopes gently over a width of 60-100 km from the Andes to the Pacific, and runs over more than 1000 km of coastal length. We find that the genesis of stepped morphology at the Andean seaboard is due to concomitant development of large west-vergent thrusts parallel to the subduction interface and increasing aridity in the Atacama Desert, which keeps an unprecedented large-scale record of interplaying tectonics and Cenozoic climate change. Incorporating our results with published geological knowledge demonstrates that Andean orogeny is characterized by trench-perpendicular (bivergent) and trench-parallel (bilateral) growth over the past 50 Myr, associated with positive trench velocity toward the continent (trench advance) and subduction of a wide slab under South America. We hypothesize that a global plate tectonic reorganisation involving long-lasting viscous mantle flow has probably forced both, Andean orogeny and global climate cooling since ~ 50 Ma. In contrast, two important stepwise pulses of increasing aridity and trench-perpendicular Andean growth appear to be results of changes in erosion rates due to global Late Eocene and Middle Miocene cooling events.
This is a compilation of articles published in the Special Issue Systematics, Morphological, and Molecular Characterization of Economically Important Plant–Parasitic Nematodes: A Themed Issue in Honor of Dr. Gary Bauchan in Plants. It includes a series of original research (seven) and review articles (four) focused on plant-parasitic nematodes including two new species description, Pratylenchus dakotaensis n.sp. and Xiphinema malaka n. sp. Nematodes are one of the most
important pests globally and can cause up to 14% loss of food crops. In total, nematodes cause over $100 billion in global crop damage annually. To date, only a few thousand PPN species have been described. Nematode identification has traditionally relied on morphological and anatomical characters using light microscopy and, in some cases, scanning electron microscopy (SCN). Lately, integrative studies combining molecular diagnosis with morphology and taxonomy are used to
accurately identify and describe nematode species. Detailed analyses of morphological and molecular data have both significantly contributed to our overall understanding of the dynamic and complex nature of plant–nematode interactions. We are grateful to all the authors who submitted their work to be included in this special issue.
The Paleocene–Miocene sedimentary successions along the Western Cordillera – Altiplano Plateau margin in southern Peru record the growth history of the northern Altiplano Plateau and the development of the foreland basin system. We evaluate the paleoelevation history of the northern Altiplano Plateau for the period of primary upper crustal shortening (i.e., Paleocene–Miocene) to determine the amount of shortening-related surface uplift. We provide new apatite fission-track and tuff zircon U–Pb ages to add to the existing age models of the strata. We further calculate the first-order approximation of paleoelevations of these formations from paleo-meteoric water δ¹⁸Omw values reconstructed from authigenic carbonate δ¹⁸Oc. The calculations show that surface elevations increased by more than 1 km along with the basin development from backbulge and foredeep to wedge-top and hinterland basins. The calculated paleoelevation of 1.8–2.4 km at the end of contractional deformation during the late Miocene indicates that a rapid surface uplift of more than 1.5 km is required to attain the modern high elevations. It is further inferred that this post-late Miocene surface uplift was probably associated with the lower crustal flow and ensuing convective removal of lower lithosphere materials.
Mountain building in the Andes, the longest continental mountain range on Earth, started in the Late Cretaceous but was highly diachronous. Reconstructing the timing of surface uplift for each of the different Andean regions is of crucial importance for our understanding of continental-scale moisture transport and atmospheric circulation, the origin and evolution of the Amazon River and Rainforest, and ultimately, the origin and evolution of species on the world most biodiverse continent. Here, I present (1) a compilation of estimates of paleoelevation for 36 geomorphological domains of the Andes from the literature, and (2) a paleoelevation reconstruction of the Andes since 80 Ma. In the northern Andes, uplift started in the Late Cretaceous (~70 Ma) in the Western and Central Cordilleras of Ecuador, while the northwestern corner of the continent was still covered by shallow seas. Mountain building migrated progressively northwards, with the Perija Range and Santander Massif uplifting since the Oligocene and the Eastern Cordillera, Garzon Massif and Mérida Andes since the Miocene. In the central Andes, uplift migrated from west to east, whereby the main phase of uplift in the Western Cordillera took place during the Late Cretaceous-Paleocene, in the western Puna plateau during the Paleocene, in the eastern Puna plateau during the early-mid Miocene, and in the Altiplano and Eastern Cordillera during the mid-late Miocene. In the southern Patagonian Andes, significant elevation was already in place at 80 Ma and in western Patagonia, modern elevations were reached in the early Eocene. A second pulse of uplift and eastward migration of the orogenic front occurred during the early-mid Miocene. The reconstruction developed here is made available as a series of raster files, so that it can be used as input for a variety of studies in the solid Earth, climate, and biological sciences, thereby being a stepping stone on the path towards a better understanding of the coevolution of the solid Earth, landscapes, climate, and life in South America.
Species of the genus Nicotiana (Solanaceae), commonly referred to as tobacco plants, are often cultivated as non-food crops and garden ornamentals. In addition to the worldwide production of tobacco leaves, they are also used as evolutionary model systems due to their complex development history, tangled by polyploidy and hybridization. Here, we assembled the plastid genomes of five tobacco species: N. knightiana, N. rustica, N. paniculata, N. obtusifolia and N. glauca. De novo assembled tobacco plastid genomes had the typical quadripartite structure, consisting of a pair of inverted repeat (IR) regions (25,323–25,369 bp each) separated by a large single-copy (LSC) region (86,510 – 86,716 bp) and a small single-copy (SSC) region (18,441–18,555 bp). Comparative analyses of Nicotiana plastid genomes with currently available Solanaceae genome sequences showed similar GC content, gene content, codon usage, simple sequence repeats, oligonucleotide repeats, RNA editing sites, and substitutions. We identified 20 highly polymorphic regions, mostly belonging to intergenic spacer regions (IGS), which could be suitable for the development of robust and cost-effective markers for inferring the phylogeny of the genus Nicotiana and family Solanaceae. Our comparative plastid genome analysis revealed that the maternal parent of the tetraploid N. rustica was the common ancestor of N. paniculata and N. knightiana, and the later species is more closely related to N. rustica. Relaxed molecular clock analyses estimated the speciation event between N. rustica and N. knightiana appeared 0.56 Ma (HPD 0.65–0.46). Biogeographical analysis supported a south-to-north range expansion and diversification for N. rustica and related species, where N. undulata and N. paniculata evolved in North/Central Peru, while N. rustica developed in Southern Peru and separated from N. knightiana, which adapted to the Southern coastal climatic regimes. We further inspected selective pressure on protein-coding genes among tobacco species to determine if this adaptation process affected the evolution of plastid genes. These analyses indicate that four genes involved in different plastid functions, including DNA replication (rpoA) and photosynthesis (atpB, ndhD and ndhF), came under positive selective pressure as a result of specific environmental conditions. Genetic mutations in these genes might have contributed to better survival and superior adaptations during the evolutionary history of tobacco species.
Keywords: Mutational hotspots, Nicotiana, plastid genomes, positive selection, substitutions, speciation
Foreland deformation has long been associated with flat-slab subduction, but the precise mechanism linking these two processes remains unclear. One example of foreland deformation corresponding in space and time to flat subduction is the Fitzcarrald Arch, a broad NE-SW trending topographically high feature covering an area of >4 × 10⁵ km² in the Peruvian Andean foreland. Recent imaging of the southern segment of Peruvian flat slab shows that the shallowest part of the slab, which corresponds to the subducted Nazca Ridge northeast of the present intersection of the ridge and the Peruvian trench, extends up to and partly under the southwestern edge of the arch. Here, we evaluate models for the formation of this foreland arch and find that a basal-shear model is most consistent with observations. We calculate that ~5 km of lower crustal thickening would be sufficient to generate the arch's uplift since the late Miocene. This magnitude is consistent with prior observations of unusually thickened crust in the Andes immediately south of the subducted ridge that may also have been induced by flat subduction. This suggests that the Fitzcarrald Arch's formation by the Nazca Ridge may be one of the clearest examples of upper plate deformation induced through basal shear observed in a flat-slab subduction setting. We then explore the more general implications of our results for understanding deformation above flat slabs in the geologic past.
L’étude des modifications phénotypiques et génomiques associées à l’adaptation des pathogènes aux résistances est une étape fondamentale pour mieux comprendre et anticiper le phénomène de contournement des résistances. Le nématode à kyste Globodera pallida est un important pathogène de la pomme de terre, vis-à-vis duquel un QTL majeur de résistance, GpaVvrn, a été identifié chez Solanum vernei. Cependant, la capacité des populations de G. pallida à s’adapter à cette résistance en quelques générations seulement a été mise en évidence par évolution expérimentale. Dans ce contexte, ce travail de thèse avait pour objectifs (1) d’étudier les traits d’histoire de vie du nématode impactés par l’adaptation, afin de tester l’existence éventuelle d’un coût de virulence, et (2) d’identifier les régions génomiques impliquées dans l’adaptation, par une approche originale combinant évolution expérimentale et scans génomiques sur des lignées virulentes et avirulentes. Contre toute attente, nous avons montré que l’adaptation à la résistance issue de S. vernei entraînait une augmentation de la fitness des individus virulents sur hôte sensible. Nous avons également pu identifier des régions génomiques candidates à l’adaptation à la résistance de la plante hôte, contenant des gènes codant pour des effecteurs, et notamment des SPRYSECs, connus chez les nématodes à kyste pour être impliqués dans la suppression des défenses des plantes mais aussi dans la virulence du nématode. À terme, ces résultats s’avéreront utiles pour la conception de stratégies durables de déploiement de variétés de pommes de terre résistantes.
The central Altiplano is inferred to have experienced surface uplift between ∼10 and 6 Ma, while the southern Altiplano experienced a similar magnitude of surface uplift that began earlier, between ∼16 and 9 Ma. To properly constrain the along strike timing of the Altiplano plateau surface uplift, it is necessary to know how and when the northernmost part of the Altiplano plateau evolved. We reconstruct the paleoclimate and infer the corresponding paleoelevation from the Miocene–Pliocene deposits of the Descanso–Yauri basin (14–15°S) in the northernmost part of the Altiplano plateau using 4 different proxies, including carbonate clumped isotope composition (i.e., values), carbonate , leaf wax and pollen assemblages from paleosol, lacustrine and palustrine carbonates and organic-rich sediments. The isotopic signatures reflect past climate conditions of mean annual air temperature ( ) and meteoric water isotope values ( , ). Our results show that the northernmost plateau remained at low elevation ( to ) until late Miocene time (∼9 Ma) characterized by ∼15 °C warmer than modern temperature (mean annual air temperature of , 2σ), low elevation vegetation and precipitation signature with reconstructed □ (VSMOW) of from carbonate ( ) and from leaf wax ( ). Modern elevations of 4 km were not reached until , as indicated by a negative shift in (VSMOW) from to between and . The timing of surface uplift of the northernmost Altiplano is consistent with the evidence for late Miocene surface uplift of the central Altiplano (16–19°S) between 10 and 6 Ma, and indicates that regional scale uplift in the northern–central plateau significantly postdates the onset of surface uplift in the southern Altiplano (19–22°S) between ∼16 and 9 Ma. These results are consistent with piecemeal removal of the lower dense lithosphere, combined with possible lower/middle crustal flow from south to north in the plateau acting as the main mechanisms for the formation of the Altiplano plateau.
The Andes, along with the Amazon and Atlantic forests, harbor the richest avifauna in the world with roughly one third of all the world’s species of birds. Many biogeographical studies have sought to explain the origin and diversification of Andean taxa. However, because of the Andes’ extensive latitudinal span and complexity, there is no one single cause of origin or of diversification that can explain the diversity found in them.
Along the Andes, multiple biogeographic patterns of disjunction between highland and lowland sister-groups have been linked to Andean uplift. For example, Ribas et al. (2007) provided evidence that the spatio-temporal diversification in the monophyletic parrot genus Pionus is causally linked to Andean tectonic and palaeoclimate change through vicariance. Thus, if the Andes uplift is responsible for some of the patterns of montanelowland disjunctions, it may be one of the mechanisms underlying the taxonomic assembly of the Andean montane avifauna.
In this dissertation I explored whether the origin and diversification of three groups of Andean birds—the exclusively Andean parrot genera Hapalopsittaca, the subclade of mangoes containing Doryfera, Schistes, and Colibri, and the ovenbirds of the tribe Thripophagini—can be linked to Earth history.
The results show that the origin of these Andean taxa can be explained through vicariance from their lowland sister-groups, mediated by the uplift of the Andes. Thus, this thesis proposes that geological events are directly responsible for originating diversity throughout montane environments. Once in the Andes, the diversification of these montane taxa can be explained by events such as the tectonic evolution of the Andes—which created canyons and valleys that may have caused the vicariance of continuous populations—as well as by the climatic oscillation of the Pleistocene, which caused altitudinal shifts, expansion, and contraction of the montane vegetation belts during the climatic oscillations of the Pleistocene.
In summary a significant part of the temporal patterns of origins and diversification of the three groups of birds included in this study can be linked to Earth history, both in terms of the tectonic history of the Andes and of the climatic events of the Pleistocene.
During the past few years, palaeontologists have agreed first that a land route was present between North and South America during the latest Cretaceous, and that this route still existed during the Palaeocene. Thus far, studies dealing with this problem have been based on tetrapod vertebrates only. In this study, data provided by tetrapods are listed and reevaluated. Moreover, information provided by fresh water fishes are taken into account. The terrestrial bridges which linked North and South America by latest Cretaceous and Palaeocene times probably comprised the Greater Antilles and the Aves Ridge which consisted of a magmatic submitted to uplift and deformation between North and South America at that time. Part of this arc began to collide with both North and South America during the Campanian, an age which corresponds to the beginning of the faunal interchanges. Another volcanic arc was present at that time on the southwestern margin of the Caribbean plate but it was very probably highly discontinuous and therefore could not act as a land bridge. -from English summary
Solanum sect. Petota series Conicibaccata is a group of 40 wild potato species, composed of diploids, tetraploids, and hexaploids, distributed from central Mexico to central Bolivia. This study examined their species boundaries and interrelationships by phenetic analyses of morphological data and cladistic analyses of chloroplast DNA restriction site data. Mitotic chromosome counts were obtained for 114 accessions; species whose first counts are reported here are S. garcia-barrigae, S. orocense, and S. sucubuncnse. Most results were concordant in showing three main groups of species: 1) tetraploids and hexaploids from central Mexico to southern Ecuador; 2) diploids from northern Peru to Bolivia, included in a cpDNA clade of diploids and hexaploids assigned to ser. Demissa and ser. Tuberosa, and 3) diploids and tetraploids from southern Colombia to Peru, cladistically related to members of ser. Piuranu. Some species boundaries, and even series boundaries of ser. Conicibaccata and ser. Piurana, are supported morphologically only by a combination of widely overlapping character states, none of which is constant for a species. Other species have no support, and it is likely that too many species are recognized in the group. The cladistic analysis of chloroplast DNA data suggested that some species represent a combination of apospecies and plesiospecies, and some populations are of possible hybrid origin.
A phylogenetic analysis of Solanum based on chloroplast DNA restriction site variation confirms previous findings that Lycopersicon and Cyphomandra are derived from within Solanum. Three out of four Solanum subgenera with more than one representative in this analysis (Minon, Potatoe, Solanum) are found to be polyphyletic, suggesting that the subgeneric classification of the genus needs revision. Subgenus Leptostemonum is monophyletic within the context of our sampling. Three primary clades can be distinguished within Solanum. Clade I includes representatives of sections Archaesolanum, Dulcamara, Holophylla, Jasminosolanum, and Solanum. Clade II includes members of subgenus Potatoe (sections Basarthrum, Lycopersicon, and Petota). Clade III includes all representatives sampled from subg. Leptostemonum, sects. Allophyllum, Brevantherum, Geminata, Pseduocapsicum, and Cyphomandropsis, and species formerly assigned to Cyphomandra. Solanum as a whole and each of the three primary clades apppear to be New World in origin. Within Leptostemonum, African and Australian members are derived from New World ancestors.
The hummingbird genus Metallura comprises nine species. Six of them live at the treeline and replace each other sharply along the eastern slope of the tropical Andes (williami, baroni, odomae, theresiae, eupogon, and aeneocauda). Their ranges overlap for 3,000 km along the Andes with M. tyrianthina, which lives at lower elevations and is differentiated into several subspecies that show clinal variation. The genus also includes M. phoebe in semi-arid western Peru and M. iracunda in the Perija Mountains of the northern Andes. The group could be a good model to study relative differences in diversification between montane forest as such and the narrow transition zone toward the barren highlands. Analysis of nucleotide sequences from three different mitochondrial gene fragments (cytochrome b, ND2, and ND5) show that Metallura forms a monophyletic group whose sister taxon is the genus Chalcostigma. The treeline forms of metallura, including the morphologically divergent M. phoebe, group in a clade sister to M. tyrianthina, confirming the idea that montane forest and treeline forms are sister taxa in a strict sense. Neighboring treeline species show greater morphological and genetic differentiation relative to neighboring montane forest forms. The split between mid-elevation and treeline forms is estimated to have occurred during the Pliocene, suggesting that much of the Metallura radiation took place during the Pleistocene.
We explore canyon incision history of the western margin of the
Andean (Altiplano-Puna) plateau in the central Andes as a proxy for
surface uplift. (U-Th)/He apatite data show rapid cooling beginning
at ca. 9 Ma and continuing to ca. 5.1 Ma in response to incision. A
minimum of 1.0 km of incision took place during that interval. The
youngest apatite date and a volcanic fl ow perched 125 m above the
present valley fl oor dated at 2.261 ± 0.046 Ma (40Ar/39Ar) show that an
additional ~1.4 km of incision occurred between ca. 5.1 and 2.3 Ma.
Thus, we infer that a total of at least 2.4 km, or 75% of the present
canyon depth was incised after ca. 9 Ma. (U-Th)/He zircon data collected
along the same transect imply that the western margin of the
plateau was warped upward into its present monoclinal form, rather
than uplift being accommodated on major surface-breaking faults.
The elevation of Earth's surface is among the most difficult environmental variables to reconstruct from the geological record. Here we describe an approach to paleoaltimetry based on independent and simultaneous determinations of soil temperatures and the oxygen isotope compositions of soil waters, constrained by measurements of abundances of 13C-18O bonds in soil carbonates. We use this approach to show that the Altiplano plateau in the Bolivian Andes rose at an average rate of 1.03 +/- 0.12 millimeters per year between approximately 10.3 and approximately 6.7 million years ago. This rate is consistent with the removal of dense lower crust and/or lithospheric mantle as the cause of elevation gain.
1] Structural mapping, 40 Ar/ 39 Ar and fission track thermochronology, U-Pb geochronology, and basin analysis reveal rapid cooling during middle Eocene– late Oligocene and late Miocene–Pliocene exhumation in the central Andean plateau of Bolivia. In the 4– 6 km high Cordillera Real, numerous granites and SW directed fold-thrust structures define the central Andean backthrust belt along the Altiplano–Eastern Cordillera boundary. U-Pb zircon analyses indicate Permo-Triassic granitic magmatism, with less extensive magmatism of late Oligocene age. Mapping reveals low magnitudes of slip (<2–5 km) for most faults on the basis of unit thicknesses, stratigraphic separation, and cutoff relationships. These results suggest that a deeper structure was probably involved in exhumation of rocks from >5 km depth. The $26 Ma Quimsa Cruz granite postdated most thrust structures, suggesting that upper crustal shortening in the Cordillera Real had largely ceased by late Oligocene time. Results of 40 Ar/ 39 Ar and fission track modeling help constrain the moderate to low-temperature (<350°C) cooling history, revealing two phases of rapid cooling from 45–40 Ma to 26 Ma and from $11 Ma onward. Initial cooling coincided with middle Eocene–late Oligocene deformation in the backthrust belt and associated deposition of coarse clastic sediments in the Altiplano basin. Eocene-Oligocene exhumation of $7.5 km of upper crust is estimated on the basis of thermochronologic data. Rapid late Miocene and younger cooling involved an estimated $3.5 km of exhumation and occurred in the apparent absence of upper crustal shortening. These findings suggest that crustal shortening and resultant exhumation of middle Eocene–late Oligocene age played a major role in construction of the central Andes. However, for late Miocene exhumation, the importance of alternative, nonshortening mechanisms is difficult to ascertain due to a poor understanding of subsurface structures. We speculate that greater precipitation on the eastern edge of the central Andean plateau north of $17.5°S was a key factor in driving rapid, youthful exhumation of the Cordillera Real. Citation: Gillis, R. J., B. K. Horton, and M. Grove (2006), Thermochronology, geochronology, and upper crustal structure of the Cordillera Real: Implications for Cenozoic exhumation of the central Andean plateau, Tectonics, 25, TC6007, doi:10.1029/2005TC001887.
The Cordillera Huayhuash is a north-south-oriented range along the drainage divide of the northern Peruvian Andes. The range has high topography with peaks in excess of 5500 m and the second-highest peak in Peru, Nevados Yerupaja (6617 m). Bedrock is dominated by folded Mesozoic miogeoclinal rocks unconformably overlain by mid-Tertiary volcanics intruded by Late Tertiary granitic rocks and silicic dikes. Zircon fission track (ZFT) and (U-Th)/He (ZHe) dating of zircons along a west-east transect elucidates the thermal evolution of exhumed and uplifted rocks. The stability of fission tracks in zircons is a function of single-grain radiation damage. In samples with grain-to-grain variability in radiation damage, resetting results in variable resetting and multiple age populations. Low retentive zircons (LRZs), which have a partly disordered crystalline structure, have significant radiation damage and a low temperature of annealing (ca. 180–200C). High retentive zircons (HRZs), which are nearly crystalline, fully anneal at temperatures in excess of ca. 280–300C. Partly reset samples are those where LRZs are reset and HRZs are not reset, and therefore the cooling age is not concordant, but the young population of grain ages records the youngest thermal event. Full resetting of both LRZs and HRZs results in cooling ages that are concordant or nearly so. Lower Cretaceous quartzites show ZFT ages with a wide range of cooling ages, but most have LRZ reset ages at ca. 27 and 63 Ma. The ZFT ages from three quartzites and two granites from the core of the range yielded a single mean reset age of Ma. The ZHe ages from four samples in these rocks ranged from 10 to 7 Ma, with older ages away 11.4 1 from the high topography. Together, the ZFT and ZHe cooling ages near the core of the range indicate moderate to rapid postintrusive cooling in the Miocene and a high Miocene geothermal gradient (ca. 40–50C/km). This widespread cooling age represents a falling geotherm, not a period of significant exhumation. Estimations of the thickness of preexhumation cover rock suggest that nearly 5 km of unroofing has occurred since the eruption of the Puscanturpa Formation (Huayllay Formation) at ca. 6.2 Ma. Exhumation was driven by valley incision initiated by uplift of this part of the Andes between 5 and 6 Ma. The high topography may have been formed by isostatic response to canyon incision. Therefore, the thermochronologic record of uplift and canyon incision is not yet apparent in the low-temperature thermochronology (for zircons) of these rocks.
Although the Andes are believed to have resulted mainly from crustal shortening, the shortening history remains debated and appears to require lateral (along-strike) crustal flow. Three-dimensional viscous flow modeling shows that, within geological uncertainties, the Andes may have been produced by either Neogene shortening alone or with significant pre-Neogene shortening. These scenarios require major along-strike crustal flow and predict significantly different histories of uplift and crustal motion.
SummaryA taxonomic review of the Neotropical nymphaline butterfly genus Hypanartia Hübner is presented, including notes on the taxonomy, biology and distribution of its component species, illustrations of all taxa and the male genitalia of all species, and the description of four new species and two new subspecies: Hypanartia celestia sp.n., H. cinderella sp.n., H. dione disjuncta ssp.n., H. fassli sp.n., H. trimaculata sp.n. and H. trimaculata autumna ssp.n. Hypanartia arcaei (Salvin) is placed as a subspecies of H. dione (Latreille) (stat.n.) and lectotypes are designated for eight nominal taxa. Fourteen species are recognized, with the centre of diversity being in high Andean cloud forest habitats. A cladistic analysis was conducted, based on fifty-three illustrated characters of male genitalic and abdominal morphology, and external facies, to investigate phylogenetic relationships. The resulting phylogenetic hypothesis was used to test four different geographical mechanisms of speciation in the Andes: colonization from temperate latitudes, speciation across elevational gradients, radiation within the Andes and allopatric speciation between the Andes and other montane regions. There is evidence that speciation across an elevational gradient occurred twice, both times into elevations largely unoccupied by the genus, and in both cases followed by subsequent, elevationally sympatric, in situ radiation. Differentiation in allopatry between montane regions has apparently been of recent influence only, causing infraspecific variation in two species. These results parallel several recent studies of Andean bird speciation.
The use of genetic resources could be more effective and efficient if we were able to predict the presence or absence of useful traits in different populations or accessions. We analyzed the extent to which taxonomic, geographic and ecological factors can predict the presence of frost tolerance in wild potatoes. We used screening data for 1646 samples from 87 species that had been collected in 12 countries in the Americas. There was a strong association of frost tolerance with species and to a lesser extent with taxonomic series. There was significant geographic clustering of areas with wild potatoes with similar levels of frost tolerance. Areas with a high level of frost tolerance are the central and southern Peruvian Andes, the lowlands of Argentina and adjacent areas, and a small area in the central Chilean Andes. There is a greater chance of finding wild potatoes with high levels of frost tolerance in areas with a yearly mean minimum temperature below 3 °C than
there is in warmer areas. However, temperature is only a weak predictor of frost tolerance. Temperature data alone did not predict observed frost tolerance in eastern Argentina/Uruguay and falsely predicted it in the southwestern United States. Because many wild potato species occur over small areas, taxonomic, ecological, and geographical factors are difficult to disentangle.
TheOxalis tuberosa alliance is a group of morphologically similarOxalis species allied to the Andean tuber crop oca,O. tuberosa. Originally described by cytologists as a dozen species sharing a base chromosome number rare inOxalis (x = 8), the alliance as defined here includes additional species for which cytological information is not yet available but which are supported as members on molecular and/or morphological grounds. The alliance includes members found in the Andean region from Venezuela to northern Argentina, with one species at high elevations in Central America. They occur from the high Andean steppes (páramo and puna) to the cloud forests of middle elevations and include both restricted endemics and variable widespread species complexes.
Geographical and altitudinal distributions of members of the alliance and selectedOxalis species outside the alliance were compared with a combined phylogenetic analysis of DNA sequence data of ITS and ncpGS (chloroplast-expressed glutamine synthetase). Groups within the alliance (i.e., major clades on the molecular trees) occur across widespread, overlapping regions in the Andes, with only partial ecological separation. The hypothesis that theO. tuberosa alliance may have developed in the Andes of southern Peru and northwestern Bolivia and radiated southward and, especially, northward along the Andean axis is suggested by patterns of distributions of members of the alliance and outgroups. In spite of uncertain species delimitations, it is clear that the alliance includes many endemic species and ecotypes that have very restricted distributions. As relatives of the Andean tuber cropOxalis tuberosa, the genetic diversity represented by this geographical variability should be a high priority for conservation.
The dispersal of megathermal angiosperms between tectonic plates is reviewed on the basis of fossil evidence for the Cretaceous and Tertiary periods, since the radiation of the angiosperms, and the period of break-up of Gondwana. The combination of tectonic plate disassembly and redistribution, coupled with phases of global warming followed by pronounced cooling, has resulted in the formation of intermittent dispersal opportunities for frost-intolerant plants, and has been a major factor in determining the direction of angiosperm diversification. The Early Cretaceous radiation of angiosperms seems to show little relationship to the formation of Tethys. However, for the Late Cretaceous and Tertiary nine relevant dispersal routes can be differentiated that can be divided into two distinct categories: routes which formed following the break-up of Gondwana during the Late Cretaceous and Earlier Tertiary, when warm climates encouraged dispersal of megathermal elements globally, and routes which formed since the Middle Eocene, following phases of plate collision, as global climates were cooling down, inhibiting such dispersal. Most inter-plate dispersal of megathermal angiosperms took place in the Late Cretaceous and Early Tertiary at a time when global climates were markedly different from those of today, and the global area of megathermal vegetation several times greater than at present. Under such a scenario, it is likely than opportunities for speciation were much higher than for present-day megathermal plants.
Integrated studies and revisions of sedimentary basins and associated magmatism in Peru and Bolivia (8–22°S) show that this part of western Gondwana underwent rifting during the Late Permian–Middle Jurassic interval. Rifting started in central Peru in the Late Permian and propagated southwards into Bolivia until the Liassic/Dogger, along an axis that coincides with the present Eastern Cordillera. Southwest of this region, lithospheric thinning developed in the Early Jurassic and culminated in the Middle Jurassic, producing considerable subsidence in the Arequipa basin of southern Peru. This ∼110-Ma-long interval of lithospheric thinning ended ∼160 Ma with the onset of Malm–earliest Cretaceous partial rift inversion in the Eastern Cordillera area.The lithospheric heterogeneities inherited from these processes are likely to have largely influenced the distribution and features of younger compressional and/or transpressional deformations. In particular, the Altiplano plateau corresponds to a paleotectonic domain of “normal” lithospheric thickness that was bounded by two elongated areas underlain by thinned lithosphere. The high Eastern Cordillera of Peru and Bolivia results from Late Oligocene–Neogene intense inversion of the easternmost thinned area.
A variety of evidence suggests that the Altiplano of the Central Andes, the second highest and largest plateau on earth, underwent significant uplift in the late Miocene–Pliocene. The most important datum supporting recent uplift is a collection of the 10.66±0.06 Ma Jakokkota flora from west-central Bolivia, which implies a paleoelevation no more than 1600±1200 m; today the site has an elevation of almost 4000 m. In order to test the reliability of this estimate, the present study analyzes a new collection of the Jakokkota flora from a lacustrine unit that is 0.2–0.5 Myr younger than the previously analyzed collection from a fluvial unit. Climate estimates based on leaf morphology for the two collections are statistically indistinguishable; the combined flora has a mean annual temperature of 21.5±2.0°C and a mean annual precipitation of 550±180 mm. The similarity of the climate estimates for the two floras suggests that there was not a significant climate change between them, nor a significant bias in the leaf morphology due to differing taphonomic processes. The climate estimate for the combined flora thus presents a representative picture of the late Miocene climate of the northern Altiplano. If one assumes that the climate of the tropics has not changed significantly since the late Miocene, as is suggested by marine isotopic data, then the paleoclimate of the Jakokkota flora implies a paleoelevation of 1160±600 m. Thus, the Jakokkota flora supports the hypothesis of a young age for the Altiplano.
In the Central Andes, crustal thickness is not well correlated to upper crustal shortening. Only little shortening is documented in the upper crust of the 60-65 km-thick Altiplano plateau, whose thickening and uplift were delayed with respect to earlier and greater thickening in the adjacent Western and Eastern Cordilleras. Because crustal thickness variations induce horizontal stress gradients and cause crustal flow, a thickness-dependent channel flow is modeled here and applied to the Central Andes. In situ thickening is assumed for both cordilleras, while the Altiplano crustal thickening is generated by lateral flow from these overthickened adjacent domains. A ~8.1018 Pa s viscosity channel is predicted for crustal thicknesses exceeding 45-50 km to match the estimated topographic evolution of the Central Andes. Thickening in the cordilleras was sufficient to generate a flow of 6.109 m3 per unit length toward the initially ~30-35 km-thick Altiplano.
The concept of ‘Gondwana’, an ancient Southern Hemisphere supercontinent, is firmly established in geological and biogeographical models of Earth history. The term Gondwana (Gondwanaland of some authors) derives from the recognition by workers at the Indian Geological Survey in the mid- to late 19th century of a distinctive sedimentary sequence preserved in east central India. This succession, now known to range in age from Permian to Cretaceous, is lithologically and palaeontologically similar to coeval non-marine sedimentary successions developed in most of the Southern Hemisphere continents suggesting former continuity of these landmasses. Palaeomagnetic data and tectonic reconstructions suggest that the main assembly of Gondwana took place around the beginning of the Palaeozoic in near-equatorial latitudes and that the supercontinent as a whole shifted into high southern latitudes, allowing widespread glaciation by the end of the Carboniferous. From Carboniferous to Cretaceous times the southern continents had broadly similar floras but some species-level provincialism is apparent at all times. The break-up of Gondwana initiated during the Jurassic (at about 180 million years ago) and this process is continuing. The earliest rifting (crustal attenuation) within the supercontinent initiated in the west (between South America and Africa) and in general terms the rifting pattern propagated eastward with major phases of continental fragmentation in the Early Cretaceous and Late Cretaceous to Paleogene. Gondwanan floras show radical turnovers near the end of the Carboniferous, end of the Permian and the end of the Triassic that appear to be unrelated to isolation or fragmentation of the supercontinent. Throughout the late Palaeozoic and Mesozoic the high-latitude southern floras maintained a distinctly different composition to the palaeoequatorial and boreal regions even though they remained in physical connection with Laurasia for much of this time. Gondwanan floras of the Jurassic and Early Cretaceous (times immediately preceding and during break-up) were dominated by araucarian and podocarp conifers and a range of enigmatic seed-fern groups. Angiosperms became established in the region as early as the Aptian (before the final break-up events) and steadily diversified during the Cretaceous, apparently at the expense of many seed-fern groups. Hypotheses invoking vicariance or long distance dispersal to account for the biogeographic patterns evident in the floras of Southern Hemisphere continents all rely on a firm understanding of the timing and sequence of Gondwanan continental breakup. This paper aims to summarise the current understanding of the geochronological framework of Gondwanan breakup against which these biogeographic models may be tested. Most phytogeographic studies deal with the extant, angiosperm-dominated floras of these landmasses. This paper also presents an overview of pre-Cenozoic, gymnosperm-dominated, floristic provincialism in Gondwana. It documents the broad succession of pre-angiosperm floras, highlights the distinctive elements of the Early Cretaceous Gondwanan floras immediately preceding the appearance of angiosperms and suggests that latitudinal controls strongly influenced the composition of Gondwanan floras through time even in the absence of marine barriers between Gondwana and the northern continents.
Paleoelevation reconstruction using stable isotopes, although a relatively new science, is making a signifi cant contribution to our understanding of the recent growth of the world's major orogens. In this review we examine the use of both light stable isotopes of oxygen and the new "clumped-isotope" (Δ47) carbonate thermometer in carbonates from soils. Globally, the oxygen isotopic composition (δ18O) of rainfall decreases on average by about 2.8 ‰/km of elevation gain. This effect of elevation will in turn be archived in the δ18O value of soil carbonates, and paleoelevation can be reconstructed, provided (1) temperature of formation can be estimated, (2) the effects of evaporation are small, (3) the effects of climate change can be accounted for, and (4) the isotopic composition of the carbonate is not diagenetically altered. We review data from modern soils to evaluate some these issues and fi nd that evaporation commonly elevates δ18O values of carbonates in deserts, an effect that would lead to underestimates of paleoelevation. Some assessment of paleoaridity, using qualitative indicators or carbon isotopes from soil carbonate, is therefore useful in evaluating the oxygen isotope-based estimates of paleoelevation. Sampling from deep (> 50 cm) in paleosols helps reduce the uncertainties arising from seasonal temperature fl uctuations and from evaporation. The new "clumped-isotope" (Δ47) carbonate thermometer, expressed as Δ47, offers an in- dependent and potentially very powerful approach to paleoelevation reconstruction. In contrast to the use of δ18O values, nothing need be known about the isotopic composition of water from which carbonate grew in order to estimate of temperature of carbonate formation from Δ47 values. Using assumed temperature lapse rates with elevation, paleoelevations can thereby be reconstructed. Case studies from the Andes and Tibet show how these methods can be used alone or in combination to estimate paleoelevation. In both cases, the potential for diagenetic alteration
The geographic distribution of wild potatoes (Solanaceae sect. Petota) was analyzed using a database of 6073 georeferenced observations. Wild potatoes occur in 16 countries, but 88% of the observations are from Argentina, Bolivia, Mexico, and Peru. Most species are rare and narrowly endemic: for 77 species the largest distance between two observations of the same species is <100 km. Peru has the highest number of species (93), followed by Bolivia (39). A grid of 50 × 50 km cells and a circular neighborhood with a radius of 50 km to assign points to grid cells was used to map species richness. High species richness occurs in northern Argentina, central Bolivia, central Ecuador, central Mexico, and south and north-central Peru. The highest number of species in a grid cell (22) occurs in southern Peru. To include all species at least once, 59 grid cells need to be selected (out of 1317 cells with observations). Wild potatoes occur between 38° N and 41° S, with more species in the southern hemisphere. Species richness is highest between 8° and 20° S and around 20° N. Wild potatoes typically occur between 2000 and 4000 m altitude.
The juveniles of Globodera "mexicana" invade the roots of potato and tomato, but only in the latter they initiate syncytia and develop into adult males and females. In vitro hybridisations were conducted between five populations of G. "mexicana" and two of G. pallida. Back-crosses were also made using females of G. pallida. The behaviour of the hybrids was studied on potato and tomato cultivated in Petri dishes. The F1s were able to induce syncytia in both plants. Depending of the G. pallida population used, these syncytia allowed the nematodes to develop into both male and female or only into male. In the latter case, the ability to develop into female increased with the number of back-crosses. The degree of cytoplasmic incompatibility depends of the parents used. With the Duddingston population of G. pallida Pa1, the incompatibility was weak. These results are used to discuss the concept of species and speciation.
All eukaryote populations accumulate mutations in their mitochondrialDNA (mtDNA) over time, so reproductively isolated populationsbecome characterized by distinct mtDNA lineages. In addition,the degree of genetic differentiation among distinct populationscan be used to estimate time elapsed since their isolation.We have identified an informative system for calibrating themtDNA "clock" by genetically comparing freshwater galaxiid fishpopulations isolated in different river drainages. Calibrationusing a range of Quaternary geological events in southern NewZealand shows that the mtDNA divergence rate in galaxiid fishesis between 1% and 2%/100 k.y. up to 250 k.y., with the ratedecreasing with increasing age. The estimated divergence rateslows to around 4%/m.y. for the middle Quaternary, althoughcalibration is poor. A calibration curve has been fitted toall data: divergence (%) = -2.2e-9t + 2.5t + 2.2,where t is isolation age (in m.y.). This molecular clock haspotential as a dating tool for glacially related and activetectonic events that have caused river drainage changes in thelate Quaternary in the Southern Hemisphere, where galaxiidsare widespread. An application of this dating tool to an examplein northern South Island uses three different species of freshwater-limitedfish, and all three data sets imply formation of a drainagedivide at 320 ± 110 ka, at about the time of a majorglacial advance though the divide (oxygen isotope stage 8).
The age of onset of hyperaridity in the Atacama Desert, Chile, which is
needed to validate geological and climatological concepts, has been
heretofore uncertain. Measurement of cosmogenic 21Ne in
clasts from erosion-sensitive sediment surfaces in northern Chile shows
that these surfaces have been barely affected by erosion since 25 Ma.
Surface exposure ages of sediment clasts give replicate values at 25,
20, and 14 Ma and individual values at 37 and 9 Ma. Predominantly
hyperarid conditions are required to preserve these oldest continuously
exposed surfaces on Earth. Our findings are compatible with the
hypothesis that the onset of aridity in the Atacama Desert could be the
reason for, rather than the consequence of, uplift of the high Andes.