Jaime A. Chaves

Universidad San Francisco de Quito (USFQ) · Department of Biology

Pinnipeds found across islands provide an ideal opportunity to examine the evolutionary process of population subdivision affected by several mechanisms. Here, we report the genetic consequences of the geographic distribution of rookeries in Galapagos fur seals (GFS: Arctocephalus galapagoensis) in creating population structure. We show that rooker...

Urbanization transforms environments in ways that alter biological evolution. We examined whether urban environmental change drives parallel evolution by sampling 110,019 white clover plants from 6169 populations in 160 cities globally. Plants were assayed for a Mendelian antiherbivore defense that also affects tolerance to abiotic stressors. Urban...

Urbanization transforms environments in ways that alter biological evolution. We examined whether urban environmental change drives parallel evolution by sampling 110,019 white clover plants from 6169 populations in 160 cities globally. Plants were assayed for a Mendelian antiherbivore defense that also affects tolerance to abiotic stressors. Urban...

Emerging evidence suggests that humans shape the ecology and evolution of species interactions. Islands are particularly susceptible to anthropogenic disturbance due to the fragility of their ecosystems; however, we know little about the susceptibility of species interactions to urbanization on islands. To address this gap, we studied how the earli...

Shark fishing, driven by the fin trade, is the primary cause of global shark population declines. Here, we present a case study that exemplifies how industrial fisheries are likely depleting shark populations in the Eastern Tropical Pacific Ocean. In August 2017, the vessel Fu Yuan Yu Leng 999, of Chinese flag, was detained while crossing through t...

Urbanization is expanding worldwide with major consequences for organisms. Anthropogenic factors can reduce the fitness of animals but may have benefits, such as consistent human food availability. Understanding anthropogenic trade‐offs is critical in environments with variable levels of natural food availability, such as the Galápagos Islands, an...

Emerging evidence suggests that urbanization shapes the ecology and evolution of species interactions. Islands are particularly susceptible to urbanization due to the fragility of their ecosystems; however, few studies have examined the effects of urbanization on species interactions on islands. To address this gap, we studied the effects of urbani...

Urbanization is expanding worldwide and can have major consequences for organisms, anthropogenic factors can reduce the fitness of animals but may also have benefits, such as consistent human food availability. Understanding these trade-offs is critically important in environments with unreliable annual natural food availability, such as the Galápa...

Disruptive natural selection within populations exploiting different resources is considered to be a major driver of adaptive radiation and the production of biodiversity. Fitness functions, which describe the relationships between trait variation and fitness, can help to illuminate how this disruptive selection leads to population differentiation....

Predator‐prey interactions play a key role in the evolution of species traits through antagonistic coevolutionary arms‐races. The evolution of beak morphology in the Darwin's finches in response to competition for seed resources is a classic example of evolution by natural selection. The seeds of Tribulus cistoides are an important food source for...

Animal microbiomes play an important role in dietary adaptation, yet the extent to which microbiome changes exhibit parallel evolution is unclear. Of particular interest is an adaptation to extreme diets, such as blood, which poses special challenges in its content of proteins and lack of essential nutrients. In this study, we assessed taxonomic si...

The gut microbiota of animal hosts can be influenced by environmental factors, such as unnatural food items that are introduced by humans. Over the past 30 years, human presence has grown exponentially in the Galapagos Islands, which are home to endemic Darwin's finches. Consequently, humans have changed the environment and diet of Darwin's finches...

Parallel selection pressures in independent taxa can lead to the evolution of the same phenotype, but whether selection acts on the same molecular mechanisms may depend on the genetic biases of the convergent trait. For example, despite hundreds of genes known to regulate pigmentation, the melanocortin-1 receptor (MC1R) is repeatedly implicated in...

Urbanization is influencing patterns of biological evolution in ways that are only beginning to be explored. One potential effect of urbanization is in modifying ecological resource distributions that underlie niche differences and that thus promote and maintain species diversification. Few studies have assessed such modifications, or their potenti...

Background Darwin’s finches are a clade of 19 species of passerine birds native to the Galápagos Islands, whose biogeography, specialized beak morphologies, and dietary choices—ranging from seeds to blood—make them a classic example of adaptive radiation. While these iconic birds have been intensely studied, the composition of their gut microbiome...

The New World avian family Polioptilidae (gnatcatchers and gnatwrens) is distributed from Argentina to Canada and includes 15 species and more than 60 subspecies. No study to date has evaluated phylogenetic relationships within this family and the historical pattern of diversification within the group remains unknown. Moreover, species limits, part...

The New World avian family Polioptilidae (gnatcatchers and gnatwrens) is distributed from Argentina to Canada and includes 15 species and more than 60 subspecies. No study to date has evaluated phylogenetic relationships within this family and the historical pattern of diversification within the group remains unknown. Moreover, species limits, part...

Both Eastern and Western Pacific populations of Green Sea Turtles are sympatric in Galápagos Islands but their natal origins, developmental habitats, and migrations that are associated with reproduction are poorly understood. Individuals of the eastern Pacific Population tend to be heavily pigmented (black morphs) while those of the western Pacific...

The complex processes involved with animal migration have long been a subject of biological interest, and broad-scale movement patterns of many marine turtle populations still remain unresolved. While it is widely accepted that once marine turtles reach sexual maturity they home to natal areas for nesting or reproduction, the role of philopatry to...

Studies of highly migratory species that increase our understanding of the dynamicsof genetic diversity, migratory routes, and genetic connectivity are essential for informing conservationactions. Genetic data for green turtles Chelonia mydas from Ecuador have only been availablefrom Galápagos Islands (GPS) rookeries, but not from foraging aggregat...

Understanding the spatial ecology of wide-ranging marine species is fundamental to advancing ecological research and species management. For marine turtles, genetic studies using mitochondrial DNA (mtDNA) markers have proven invaluable to characterize movement, particularly between rookeries (i.e. nesting sites) and foraging grounds. Hawksbill turt...

Adaptive radiation unfolds as selection acts on the genetic variation underlying functional traits. The nature of this variation can be revealed by studying the tips of an ongoing adaptive radiation. We studied genomic variation at the tips of the Darwin's finch radiation; specifically focusing on polymorphism within, and variation among, three sym...

The hawksbill turtle (Eretmochelys imbricata) is currently listed as critically endangered on the IUCN Red List, and no commercial use is permitted under CITES Appendix I. In 2008 Eastern Pacific hawksbills were considered as a non-viable population and new discernments about the eastern pacific population is currently in development. E. imbricata...

alápagos is perhaps one of the most important sites in the world for some sea turtle populations. However, in-water biology studies are almost nonexistent. Current sea turtle species are key for the socio-ecological system, and are strictly protected. However, they are starting to be threatened by direct and indirect anthropogenic influences. The p...

Understanding the relationships between breeding and foraging populations of migratory marine species is vital for their conservation. Mixed Stock Analysis (MSA) using molecular techniques has proved to be an effective alternative to estimate the origin of sea turtles sampled away from their nesting sites. However, little is known about population...

There is a lack of knowledge about green sea turtle genetic composition in foraging and nesting habitats in Ecuadorean territory; however, little importance has been given to Chelonia mydas population dynamics in foraging and nesting habitats from Galápagos and mainland Ecuador. In order to ensure Ecuadorean green sea turtle populations viability a...

Prior to 2008 and the discovery of several important hawksbill turtle (Eretmochelys imbricata) nesting colonies in the EP (Eastern Pacific), the species was considered virtually absent from the region. Research since that time has yielded new insights into EP hawksbills, salient among them being the use ofmangrove estuaries for nesting. These recen...

Considered functionally extirpated as recently as 2008, information on hawksbill turtles (Eretmochelys imbricata) in the eastern Pacific Ocean remains scant, hindering management of the population. The use of molecular genetic techniques plays a critical role in the understanding and management of global sea turtle populations. Due to strong philop...

Appendix S1. Methods and results. Figure S1. Rarefication curve showing the increase in number of discovered lineages of avian haemosporidia as number of species sampled (at random) increase. Figure S2. Variable importance scores for all ecological variables and including geographic variable (latitude and longitude) used as predictors to explain av...

The northern Andes, with their steep elevational and climate gradients, are home to an exceptional diversity of flora and fauna, particularly rich in avian species that have adapted to divergent ecological conditions. With this diversity comes the opportunity for parasites to exploit a wide breadth of avian hosts. However, little research has focus...

Aim: To examine the history of diversification of blue' cardinalids (Cardinalidae) across North and South America. LocationNorth America (including Middle America) and South America. Methods: We collected 163 individuals of the 14 species of blue cardinalids and generated multilocus sequence data (3193 base pairs from one mitochondrial and three...

AimWe reconstructed the biogeographical and evolutionary history of Saltator by producing a robust phylogenetic hypothesis that we used to evaluate the geographical origins of this genus, and assessed the potential influence of major Neotropical biogeographical features on the origin of lineages within this assemblage (i.e. phylogroups). LocationNe...

The faunas associated with oceanic islands provide exceptional examples with which to examine the dispersal abilities of different taxa and test the relative contribution of selective and neutral processes in evolution. We examine the patterns of recent differentiation and the relative roles of gene flow and selection in genetic and morphological v...

The Andes are known to have influenced speciation patterns in many taxa, yet whether species diversification occurred simultaneously with their uplift or only after uplift was complete remains unknown. We examined both the phylogenetic pattern and dates of branching in Adelomyia hummingbirds in relation to Andean uplift to determine whether diversi...

The patterns of genetic diversity and morphological variation are of central importance in understanding the evolutionary process that drive diversification. We use molecular, morphological, and ecological data to explore the influence of geography and ecology in promoting speciation in the widespread Andean hummingbird genus Adelomyia. Six monophy...

The hovering flight of hummingbirds is one of the most energetically demanding forms of animal locomotion and is influenced by both atmospheric oxygen availability and air density. Montane Neotropical hummingbirds are expected to shift altitudinally upwards in response to climate change to track their ancestral climatic regime, which is predicted t...

Aim We explore the utility of newly available optical and microwave remote sensing data from the Moderate Resolution Imaging Spectroradiometer (MODIS) and QuikSCAT (QSCAT) instruments for species distribution modelling at regional to continental scales. Using eight Neotropical species from three taxonomic groups, we assess the extent to which remot...

The Andes of South America contain one of the richest avifaunas in the world, but little is known about how this diversity arises and is maintained. Variation in mitochondrial DNA and morphology within the speckled hummingbird (Adelomyia melanogenys) was used to elucidate the phylogeographic pattern along an Ecuadorian elevational gradient, from th...

Cotinga 21 (2004): 18–24 Field observations of 11 globally threatened and near-threatened species are summarised (nine of which are Tumbesian endemics), including some behavioural and ecological notes, as well as vocalisations and new sites for these species. Compiling new field information on these birds will aid the identification of new priority...

Even in well-studied countries, such as Ecuador, new distributional records and range extensions are regularly reported as unexplored or poorly known areas are surveyed (e.g. Krabbe 1992, Krabbe et al. 1997, Freile 2001a). In this note we present new records, as well as latitudinal and altitudinal range extensions for several species, taking Ridgel...