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Biology subjects

Padilla Perez, D. J.

Publications and source records attributed to Padilla Perez, D. J..

3 recordsLinked to original sources

Gene Flow and Recent Lineage Colonization Constrain Genetic Differentiation Despite Local Adaptation

Demographic processes such as colonization to new environments and gene flow fundamentally shape the genomic landscape, either facilitating or constraining the efficiency of selection by altering the balance between genetic diversity and adaptive responses. Although theoretical predictions suggest that the efficacy of selection is dictated by a species' demographic history, empirical studies often overlook these constraints, yielding misleading observations. In this study, we present the first functional genome annotation for the wood frog (Lithobates sylvaticus), providing a critical genomic resource for understanding the adaptive capacity of the species. Based on the annotation, we examined the potential for selection to drive genomic and phenotypic divergence among populations distributed across vernal ponds in Northeastern Connecticut, USA. A genotypexenvironment association analysis revealed that the frequency of an outlier loci (Rab28) spikes in response to one wetland that is notable for having relatively low canopy cover and large area. We also found that selection has driven a strong disparity in embryonic development among populations of wood frog at a rate exceeding that of neutral genetic drift. This genomic signature of selection together with a remarkable phenotypic differentiation suggests that natural selection overcomes the power of genetic drift, even in a landscape characterized by relatively recent colonization and substantial evidence of connectivity among breeding wetlands. These findings improve our understanding of the wood frog's variation at a microgeographic scale.

evolutionary biology↗

Correlated evolution of conspicuous coloration and burrowing in crayfish

Conspicuous colors have fascinated biologists for centuries, leading to much research on the evolution and functional significance of color traits. However, some authors have critiqued the adaptationist dogma amongst color researchers. When investigating a color trait, researchers often exclusively consider the alternative hypotheses--they assume color is adaptive. The null hypothesis of animal color--that coloration is non-adaptive or evolutionary neutral, is rarely considered. Here, we use phylogenetic comparative methods to investigate color evolution throughout freshwater crayfishes. Within the taxa we analyzed, conspicuous colors have evolved independently over 50 times. The intuitive, but not evolutionary-justified assumption when presented these results is to assume that these colors are an adaptation. But contrary to this intuition, our work might support the hypothesis that coloration in crayfish is neutral; because we show that conspicuous colors are evolutionary correlated to a semi-terrestrial burrowing lifestyle. Conspicuous coloration being common in semi-terrestrial burrowers is paradoxical, because these species are nocturnal, and rarely leave their burrows. Overall, our work brings into question to traditional view of animal coloration as a perfectly adapted phenotype.

evolutionary biology↗

Early transition in foraging mode promoted greater reproductive effort in widely foraging lizards

Life-history theory suggests that the optimal reproductive effort of an organism is affected by factors such as energy acquisition and predation risk. The observation that some organisms actively search for their prey and others ambush them creates the expectation of different energy needs and predation risk associated with each foraging behavior, the so-called "foraging-mode paradigm". Although this paradigm has been around for decades, the empirical evidence consists of conflicting results derived from competing models based on different mechanisms. For instance, models within the foraging-mode paradigm suggest that widely-foraging females have evolved low reproductive effort, because a heavy reproductive load decreases their ability to escape from predators. By contrast, a long-standing prediction of evolutionary theory indicates that organisms subject to high extrinsic mortality, should invest more in reproduction. Here, we present the first partial evidence that widely-foraging species have evolved greater reproductive effort than have sit-and-wait species, which we attribute to a larger body size and greater mortality among mobile foragers. According to our findings, we propose a theoretical model that could explain the observed pattern in lizards, suggesting ways for evolutionary ecologists to test mechanistic hypotheses at the intraspecific level.

evolutionary biology↗