Robert E. Ricklefs's research while affiliated with University of Missouri - St. Louis and other places

Publications (576)

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Genomic studies are now poised to explore whole communities of species. The ~70 species of woody plants that anchor the coastal ecosystems of the tropics, collectively referred to as mangroves, are particularly suited to this exploration. In this study, we de novo sequenced the whole genomes of 32 mangroves, which we combined with other sequences o...
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Biologists have considered both winter coldness and temperature seasonality as major determinants of the northern limits of plants and animals in the Northern Hemisphere, which in turn drive the well-known latitudinal diversity gradient. However, few studies have tested which of the two climate variables is the primary determinant. In this study, w...
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The Arctic is the coldest inhabited region on Earth, and it supports few terrestrial species. The tropical‐climate origin of many angiosperm clades, along with strong phylogenetic niche conservatism, likely constrained colonization of cold environments for many plants. However, invasion of the Arctic by many lineages might also have opened up a new...
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Aim: Macroecological analyses provide valuable insights into factors that influence how parasites are distributed across space and among hosts. Amid large uncertainties that arise when generalizing from local and regional findings, hierarchical approaches applied to global datasets are required to determine whether drivers of parasite infection pat...
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A Correction to this paper has been published: https://doi.org/10.1038/s41559-021-01465-5.
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Although they experience cold climates, particularly in temperate mountains during winter, alpine floras (plants in the vegetation belts above the climatic treelines) are generally species-rich. Yet, whether these floras represent evolutionarily independent, but convergent, assemblages drawn from their regional floras, or they originated from parti...
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Host phylogenetic relatedness and ecological similarity are thought to contribute to parasite community assembly and infection rates. However, recent landscape level anthropogenic changes may disrupt host-parasite systems by impacting functional and phylogenetic diversity of host communities. We examined whether changes in host functional and phylo...
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Haemosporidian parasites of the genera Plasmodium, Haemoproteus, and Leucocytozoon are among the best studied parasites of Neotropical birds. Here, we describe variation in haemosporidian prevalence (i.e. the proportion of infected individuals in a sampled population) in Neotropical birds. We review correlates of haemosporidian prevalence (includin...
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We studied avian development in 49 to 153 species of temperate and tropical New World passerine birds to determine how growth rates, and incubation and nestling periods, varied in relation to other life-history traits. We collected growth data and generated unbiased mass and tarsus growth rate estimates (mass n = 92 species, tarsus n = 49 species),...
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Species distributions and the mechanisms that produce patterns in the occupation space are recurrent themes in community ecology. Here, we examine beta diversity among assemblages of small mammals in the Cerrado domain of Brazil to partition the effects of turnover and nestedness on species distributions. Our objective was to evaluate whether balan...
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Species distributions and the mechanisms that produce patterns in the occupation space are recurrent themes in community ecology. Here, we examine beta diversity among assemblages of small mammals in the Cerrado domain of Brazil to partition the effects of turnover and nestedness on species distributions. Our objective was to evaluate whether balan...
Preprint
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Ecological specialization is widely thought to influence patterns of species richness by affecting rates at which species multiply and perish. Quantifying specialization is challenging, and using only one or a small number of ecological axes could bias estimates of overall specialization. Here, we calculate an index of specialization, based on seve...
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In temperate regions, some avian haemosporidian parasites have evolved seasonal transmission strategies, with chronic infections relapsing during spring and transmission peaking during the hosts’ breeding season. Because lineages with seasonal transmission strategies are unlikely to produce gametocytes in winter, we predicted that (1) resident bird...
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Background In the arms race between hosts and parasites, genes involved in the immune response are targets for natural selection. Toll-Like Receptor (TLR) genes play a role in parasite detection as part of the innate immune system whereas Major Histocompatibility Complex (MHC) genes encode proteins that display antigens as part of the vertebrate ad...
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We compared the parasite assemblages of over‐wintering migratory birds and permanent residents on the wintering grounds. We determined whether parasite sharing between migratory and resident birds is influenced by host phylogenetic relatedness. We then inferred whether migratory birds transport haemosporidian parasite lineages between the breeding...
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Abstract Parental care in birds varies among species and geographic regions. Incubation behavior influences embryonic development rate and varies substantially among species. We studied attendance at the nest by videoing nests or collecting data from the literature for 112 species in north temperate and lowland tropical sites, then associated patte...
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Species assemble into communities through ecological and evolutionary processes. Phylogenetic niche conservatism—the tendency of species to retain ancestral ecological distributions—is thought to influence which species from a regional species pool can persist in a particular environment. We analyzed data for seed plants in China to test hypotheses...
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The geographic distribution of genetic diversity in malaria parasite populations (Apicomplexa: Haemosporida) presumably influences local patterns of virulence and the evolution of host-resistance, but little is known about population genetic structure in these parasites. We assess the distribution of genetic diversity in the partial Domain I of api...
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We use contemporary genetic diversity to characterize the within-island population structure and historical demography of Bananaquits (Aves: Thraupidae: Coerebinae: Coereba flaveola) on the West Indian island of Puerto Rico (Greater Antilles). We relate periods of population expansion, from Puerto Rico across the Lesser Antilles, to the genetic arc...
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We assessed the phylogeography of the Carib Grackle (Quiscalus lugubris), whose distribution includes eight subspe-cies in the Lesser Antilles and northern South America. We used the geographic distribution of variation in the mitochondrial genes ATPase 6 and ATPase 8 to assess the demographic history of the species and degree of concordance betwee...
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Whether ecological differences between species evolve in parallel with lineage diversification is a fundamental issue in evolutionary biology. These processes might be connected if conditions that favor the proliferation of species, such as release from competitors, facilitate the evolution of novel ecological relationships. Despite this, phylogene...
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Aim The identification of environmental variables associated with geographical range limits can shed light on the ecological and physiological constraints imposed by abiotic stresses. Mangrove forest is a coastal ecosystem restricted to the tropics and subtropics. However, the factors that influence fine‐scale assemblage composition of mangroves re...
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The biogeographic histories of parasites and pathogens are infrequently compared with those of free-living species, including their hosts. Documenting the frequency with which parasites and pathogens disperse across geographic regions contributes to understanding not only their evolution, but also the likelihood that they may become emerging infect...
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We used the prevalence of avian haemosporidian blood parasites (Plasmodium and Haemoproteus), quantified by PCR screening and DNA sequencing, to reevaluate a previously described negative relationship, based on microscopic examination of blood smears, between the prevalence of parasites in an avian host population and the length of the embryo devel...
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Understanding how pathogens and parasites diversify through time and space is fundamental to predicting emerging infectious diseases. Here, we use biogeographic, coevolutionary and phylogenetic analyses to describe the origin, diversity, and distribution of avian malaria parasites in the most diverse avifauna on Earth. We first performed phylogenet...
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Relative abundances of tree species are presented for the 348 forest plots described in E. Lucy Braun's (1950) book, Deciduous Forests of Eastern North America (Hafner, New York, facsimile reprint 1972). Information about the plots includes forest type, location with latitude and longitude, WorldClim climate variables, and sources of original studi...
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Hawaiian honeycreepers, comprising an endemic radiation of passerine birds in the Hawaiian archipelago, have suffered losses of individual island populations and the extinction of many species as a result of colonization of the islands by Polynesians and, more recently, introduced avian pox virus and avian malaria. Here, I test the idea that popula...
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Although eastern Asia (EAS) and eastern North America (ENA) have similar climates, plant species richness in EAS greatly exceeds that in ENA. The degree to which this diversity difference reflects the ages of the floras or their rates of evolutionary diversification has not been quantified. Measures of species diversity that do not incorporate the...
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Island populations are vulnerable to introduced pathogens, as evidenced by extinction or population decline of several endemic Hawaiian birds caused by the malaria parasite, Plasmodium relictum (order Haemosporida). We analyzed blood samples from 363 birds caught near Guantánamo Bay, Cuba, for the presence of haemosporidian infections. We character...
Article
In spite of strong selection by time-dependent mortality on the length of the embryo development (incubation) period, time to hatching varies substantially among species, independently of body size. One view, strongly supported by the work of Thomas Martin and his colleagues, maintains that this variation reflects parental strategies to minimize th...
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Rarity, which is believed to influence extinction risk, can be defined in terms of local abundance, geographical range size and habitat breadth. Phylogenetic patterns in these attributes provide insight into the extent to which rarity and extinction risk are conserved during evolution and the potential for species-level heritability. We evaluated p...
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Although introduced hemosporidian (malaria) parasites (Apicomplexa: Haemosporida) have hastened the extinction of endemic bird species in the Hawaiian Islands and perhaps elsewhere, little is known about the temporal dynamics of endemic malaria parasite populations. Haemosporidian parasites do not leave informative fossils, and records of populatio...
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The tropical niche conservatism (TNC) hypothesis predicts that species in colder or drier climates should on average be more closely related to each other (more phylogenetically clustered) than those in warmer or wetter climates, but a global test of this prediction for local forest communities is lacking. In this study, we test this prediction by...
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Parasites of the genera Plasmodium and Haemoproteus (Apicomplexa: Haemosporida) are a diverse group of pathogens that infect birds nearly worldwide. Despite their ubiquity, the ecological and evolutionary factors that shape the diversity and distribution of these protozoan parasites among avian communities and geographic regions are poorly understo...
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Avian genomics, especially of non-model species, is in its infancy relative to mammalian genomics. Here, we describe the sequencing, assembly, and annotation of a new avian genome, that of the bananaquit Coereba flaveola (Passeriformes: Thraupidae). We produced ∼30-fold coverage of the genome with an assembly size of ca. 1.2 Gb, including approxima...
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Studies of community organization and clade diversification that include functional traits have become an important component of the analysis of ecological and evolved systems. Such studies frequently are limited by availability of consistently collected data. Here, I present a dataset including eight measurements of the external morphology of 1642...
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Parasite prevalence is thought to be positively related to host population density owing to enhanced contagion. However, the relationship between prevalence and local abundance of multiple host species is underexplored. We surveyed birds and their haemosporidian parasites (genera Plasmodium and Haemoproteus) at multiple sites across eastern North A...
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Quantifying the relationship between form and function can inform use of morphology as a surrogate for ecology. How the strength of this relationship varies continentally can inform understanding of evolutionary radiations; for example, does the relationship break down when certain lineages invade and diversify in novel habitats? The 75 species of...
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Aim Migrating birds transport their parasites, often over long distances, but little is known about the transfer of these parasites to resident hosts in either the wintering or breeding ranges of the migratory host populations. We investigated the haemosporidian parasite faunas of migratory and resident birds to determine connections among distant...
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Temperate plant communities have been assembled from tropical, lowland floras through different evolutionary pathways with respect to invading more recent cool environments at higher latitudes (niche conservatism) and occupying older cool environments at higher elevations within the tropics (niche convergence).
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Although shorebirds (Charadriiformes: suborders Scolopaci and Charadrii) face physiological stress during migration and experience a wide range of vector-suitable habitats across their distributions, haemosporidian parasites (order Haemosporida) have rarely been detected in these species worldwide. We ask whether shorebirds remain infection-free wh...
Article
Multiple vector-borne pathogens often circulate in the same vector and host communities, and seasonal infection dynamics influence the potential for pathogen interactions. Here, we explore the seasonal infection patterns of avian malaria (Haemosporida) parasites (genera: Plasmodium and Parahaemoproteus) and West Nile virus (WNV) in birds and mosqui...
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Hosts frequently harbor multiple parasite infections, yet patterns of parasite co-occurrence are poorly documented in nature. In this study, we asked whether two common avian blood parasites, one haemosporidian and one trypanosome, affect each other’s occurrence in individuals of a single host species. We used molecular genotyping to survey protozo...
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Aim: Much of our current understanding of ecological and evolutionary processes comes from island research. With the increasing availability of data on distributions and phylogenetic relationships and new analytical approaches to understanding the processes that shape species distributions and interactions, a re-evaluation of this ever-interesting...
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We tested the hypothesis that avian haemosporidian (malaria) parasites specialize on hosts that can be characterized as predictable resources at a site in Amazonian Ecuador. We incorporated host phylogenetic relationship and relative abundance in assessing parasite specialization, and we examined associations between parasite specialization and thr...
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We tested whether the probability of detecting avian haemosporidia (Plasmodium and Haemoproteus) using molecular techniques differs among blood, liver, heart, and pectoral muscle tissues. We used a paired design, sampling the 4 tissue types in 55 individuals of a wild South American suboscine antbird, the white-shouldered fire-eye (Pyriglena leucop...
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To determine statistical relationships between the prevalence of haemosporidian (malaria) parasites and the abundance of avian host populations across islands in the Lesser Antilles. Thirteen islands in the Lesser Antilles, from Grenada in the south to St Kitts in the north. Birds were captured by mist net and small blood samples were taken for pol...
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Global patterns of biodiversity reflect both regional and local processes, but the relative importance of local ecological limits to species coexistence, as influenced by the physical environment, in contrast to regional processes including species production, dispersal, and extinction, is poorly understood. Failure to distinguish regional influenc...
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Molecular markers can be used to infer the demographic history of a given species, but many historic processes simultaneously impact multiple species. Thus, comparative historical demography has the potential to provide insight into drivers of evolution. In this study, we used nuclear DNA (nDNA) sequences to corroborate (or refute) demographic infe...
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Haemosporidian parasites (genera Plasmodium and Haemoproteus) are common blood parasites of birds transmitted by dipteran insect vectors. We analyzed blood samples from 329 individuals of 43 bird species in eastern Tennessee to better understand the relationship between the local community of birds and their blood parasites, including the distribut...
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The prevalence of vector-borne parasites varies greatly across host species, and this heterogeneity has been used to relate infectious disease susceptibility to host species traits. However, a few empirical studies have directly associated vector-borne parasite prevalence with exposure to vectors across hosts. Here, we use DNA sequencing of blood m...
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The drivers of regional parasite distributions are poorly understood, especially in comparison with those of free-living species. For vector-transmitted parasites, in particular, distributions might be influenced by host-switching and by parasite dispersal with primary hosts and vectors. We surveyed haemosporidian blood parasites (Plasmodium and Ha...
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Understanding the complexity of host immune responses to parasite infection requires controlled experiments that can inform observational field studies. Birds and their malaria parasites provide a useful model for understanding host-parasite relationships, but this model lacks a well-described experimental context for how hosts respond immunologica...
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Ecologists broadly accept that the number of species present within a region balances regional processes of immigration and speciation against competitive and other interactions between populations that limit distribution and constrain diversity. Although ecological theory has, for a long time, addressed the premise that ecological space can be fil...
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Understanding the mechanisms that generate diversity patterns requires analyses at spatial and temporal scales that are appropriate to the dispersal capacities and ecological requirements of organisms. Oceanic archipelagos provide a range of island sizes and configurations which should predictably influence colonization, diversification and extinct...
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Patterns of diversity within large regional biotas express the outcomes of processes, operating on both regional and local scales, that influence evolutionary diversification as well as the distribution and abundance of species. Regional analyses of species distributions suggest that neither ecological sorting of species based on their adaptations...
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Understanding geographic variation in the species richness and lineage composition of regional biotas is a long standing goal in ecology. Why do some evolutionary lineages proliferate while others do not, and how do new colonists fit into an established fauna? Here, we analyse the morphological structure of assemblages of passerine birds in four bi...
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The study of islands as model systems has played an important role in the development of evolutionary and ecological theory. The 50th anniversary of MacArthur and Wilson's (December 1963) article, ‘An equilibrium theory of insular zoogeography’, was a recent milestone for this theme. Since 1963, island systems have provided new insights into the fo...
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Scheffer et al.’s recent spotlight article in TREE [1] reports a surprising bimodal pattern in the frequency distribution of the maximal heights of woody plants: one mode emerges at 2.8 m and the other at 26 m (also see [2], Figure 4b). The authors speculate that this bimodal distribution might occur if: (i) intermediate size produced an unfavorabl...
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• The growth of the avian embryo is paralleled by an exponential increase in the rate of whole-embryonic oxygen consumption, which potentially increases oxidative damage. • Age-related patterns of tissue lipid peroxidation were characterised in brain, liver and heart tissue of developing Japanese quail (Coturnix japonica) embryos between 9 and 15 d...
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Understanding variation in resource specialization is important for progress on issues that include coevolution, community assembly, ecosystem processes, and the latitudinal gradient of species richness. Herbivorous insects are useful models for studying resource specialization, and the interaction between plants and herbivorous insects is one of t...
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Knowing the genetic variation that occurs in pathogen populations and how it is distributed across geographical areas is essential to understand parasite epidemiology, local patterns of virulence, and evolution of host-resistance. In addition, it is important to identify populations of pathogens that are evolutionarily independent and thus ‘free’ t...
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How specialization of consumers with respect to resources varies with respect to latitude is poorly understood. Coexistence of many species in the tropics might be possible only if specialization also increases. Alternatively, lower average abundance of more diverse biotic resources in the tropics might force consumers to become more generalized fo...
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Parasite specialization on one or a few host species leads to a reduction in the total number of available host individuals, which may decrease transmission. However, specialists are thought to be able to compensate by increased prevalence in the host population and increased success in each individual host. Here, we use variation in host breadth a...
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The malaria parasites (Apicomplexa: Haemosporida) of birds are believed to have diversified across the avian host phylogeny well after the origin of most major host lineages. Although many symbionts with direct transmission codiversify with their hosts, mechanisms of species formation in vector-borne parasites, in-cluding the role of host shifting,...
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Abstract Many studies have tried to identify factors that explain differences in numbers of species between clades against the background assumption that older clades contain more species because they have had more time for diversity to accumulate. The finding in several recent studies that species richness of clades is decoupled from stem age has...
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Host responses to parasitism in the wild are often studied in the context of single host-parasite systems, which provide little insight into the ecological dynamics of host-parasite interactions within a community. Here we characterized immune system responses to mostly low-intensity, chronic infection by haemosporidian parasites in a sample of 424...
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Various ecological and physiological mechanisms might influence the probability that two or more pathogens may simultaneously or sequentially infect a host individual. Concurrent infections can have important consequences for host condition and fitness, including elevated mortality risks. In addition, interactions between coinfecting pathogens may...
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Abstract Inferring the underlying speciation-extinction dynamics of a clade from the phylogenetic relationships of contemporary species has proven difficult, primarily because the record of extinction is absent. Moreover, models of diversification tend to emphasize either time homogeneity or gradual trends in speciation and extinction rates. In con...