Biology subjects

Machado, A. F.

Publications and source records attributed to Machado, A. F..

3 recordsLinked to original sources

bioRxiv2023

The Role of Phylogenetic Structure on Canidae Lineage Distribution and Trait Variation across the Globe

AimUnderstanding the spatial structuring of ecological communities requires us to consider the interplay between evolutionary history and environmental factors. In this study, we investigated the influence of Canidae phylogenetic structure on the distribution and trait patterns of lineages across the planet. LocationAmericas, Africa, Eurasia. Time period12 million years ago - present. Major taxa studiedCanidae. MethodsUsing distribution data and phylogenetic information for 37 Canidae species, we employed phylogenetic fuzzy-weighting to compare assemblages based on their phylogenetic similarity. ResultsOur results revealed distinct global patterns of body size, body mass, range size, habitat type, and evolutionary distinctiveness among lineages. We also identified the shared contributions of phylogenetic structure and temperature to trait variation using variance partitioning analysis. The PCPS axes highlighted the influence of phylogenetic relationships on Canidae assemblages, particularly in South America. Main conclusionsNotably, the study challenges the applicability of Bergmanns and Rapoports rules in explaining canids sizes and range sizes geographic variation across continents, emphasizing the importance of phylogenetic information. The unique diversification history of Canidae in South America and Africa and their diverse environmental conditions likely contribute to the observed trait patterns that make both continents so distinguished when compared to N. America and Eurasia. Our findings underscore the need to incorporate phylogenetic information in models assessing trait variation across geographic scales for unbiased estimations.

evolutionary biology↗

bioRxiv2022

Landscape configurations determining the genetic structure of the Yellow-Spotted Amazon River Turtle (Podocnemis unifilis) in Brazilian Amazonia

ContextWaterfalls and rapids of Amazon basin have been suggested as causing the speciation and genetic structure of many freshwater species, including turtles. The species behavior affects the way waterfalls and rapids limit gene flow. The Yellow-spotted River Turtle (Podocnemis unifilis), a widely distributed and endangered Amazonian turtle, does not show the habit to migrate long distances for breeding or eating, but has a complex geographic pattern of genetic variation. ObjectivesHere, we investigate isolation by distance and by resistance of P. unifilis. We analyzed if the species ecological niche and waterfalls explain the genetic distance in Brazilian Amazonia. MethodsWe evaluated the P. unifilis spatial distribution of genetic variability and diversity using the control region of mitochondrial DNA. We tested the hypotheses of isolation either by distance and resistance through an integrative approach using genetic, geographic, and ecological data. We created a resistance matrix using species niche modeling. We compared the explanation power of geographical distance (both linear and in-water distance) and resistance distance on genetic distance ({Phi}ST fixation index) using multiple regressions and Mantel tests. ResultsWe found a high genetic diversity and pattern of genetic structure proved to be geographically complex. The population structure followed some watersheds but also showed structuring within different rivers. We found that landscape resistance better explains genetic distance than linear and in-water distance. ConclusionsThe resistance of the landscape influences the displacement of individuals by aquatic, vegetational, biological, and geomorphological variables, and efforts to species conservation need to be applied throughout its distribution considering landscape genetics.

molecular biology↗

bioRxiv2020

Potential mammalian species for investigating the past connections between Amazonia and the Atlantic Forest

Much evidence suggests that Amazonia and the Atlantic Forest were connected through at least three dispersion routes in the past: the northeast route, the central route, and the southeast-northwest route. According to previous studies, the southeast-northwest route would have been the most frequently used. However, few studies have assessed the use of these routes based on multiple species. Here we present a compilation of potential mammal species that could have dispersed between the two forest regions to investigate these connections. We evaluate the geographic distributions of mammals occurring in both Amazonia and the Atlantic Forest and the likely connective routes between these forests. We classified the species per habitat occupancy (strict forest specialists, species that prefer forest, or generalists) and compiled the genetic data available for each species to evaluate their potential for phylogeographic studies focusing on genetic exchange between the two forest regions. We found 127 mammalian species occurring in both Amazonia and the Atlantic Forest for which significant genetic data was available. Hence, highlighting their potential for phylogeographic studies investigating the past connections between the two forests. Differently from what was previously proposed, the northeast route showed evidence of past use by more mammal species than the remaining two routes. The central route would have been the second most important in terms of species. Our results show the potential of using mammal species to investigate and bring new insights about the past connections between Amazonia and the Atlantic Forest.

ecology↗