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Pavon-Vazquez, C. J.

Publications and source records attributed to Pavon-Vazquez, C. J..

3 recordsLinked to original sources

Integrating Genomics, Collections, and Community Science to Reveal Speciation in a Variable Monitor Lizard (Varanus tristis)

--The accurate characterization of species diversity is a vital prerequisite for ecological and evolutionary research, as well as conservation. Thus, it is necessary to generate robust hypotheses of species limits based on the inference of evolutionary processes. Integrative species delimitation, the inference of species limits based on multiple sources of evidence, can provide unique insight into species diversity and the processes behind it. However, the application of integrative approaches in non-model organisms is often limited by the amount of data that is available. Here, we show how data relevant for species delimitation can be bolstered by incorporating information from tissue collections, museum specimens, and observations made by the wider community. We show how to integrate these data under a hypothesis-driven, integrative framework by identifying the processes generating genetic and phenotypic variation in Varanus tristis, a widespread and variable complex of Australian monitor lizards. Using genomic, morphometric (linear and geometric), coloration, spatial, and environmental data we show that disparity in this complex is inconsistent with intraspecific variation and instead suggests that speciation has occurred. Based on our results, we identify the environmental factors that may have been responsible for the geographic sorting of variation. Our workflow provides a guideline for the integrative analysis of several types of data to identify the occurrence and causes of speciation. Furthermore, our study highlights how community science and machine learning--two tools used here--can be used to accelerate taxonomic research.

evolutionary biology↗

Not one, but multiple radiations underlie the biodiversity of Madagascar's endangered lemurs

Lemurs are often cited as an example of adaptive radiation. Since colonizing Madagascar, more than 100 extant lemur species have evolved to fill a variety of ecological niches on the island. However, recent work suggests that lemurs do not exhibit one of the hallmarks of other adaptive radiations: explosive speciation rates that decline over time. Thus, characterizing the tempo and mode of evolution in lemurs can help us understand alternative ways that hyperdiverse clades arise over time, which might differ from traditional models. We explore the evolution of lemurs using a phylogenomic dataset with broad taxonomic sampling that includes the lemurs sister group, the lorisiforms of Asia and continental Africa. Our analyses reveal multiple bursts of diversification (without subsequent declines) that explain much of todays lemur diversity. We also find higher rates of speciation in Madagascars lemurs compared to lorisiforms, and we demonstrate that the lemur clades with exceptionally high diversification rates have higher rates of genomic introgression. This suggests that hybridization in these primates is not an evolutionary dead-end, but a driving force for diversification. Considering the conservation crisis affecting strepsirrhine primates, with approximately 95% of species being threatened with extinction, this phylogenomic study offers a new perspective for explaining Madagascars exceptional primate diversity and reveals patterns of speciation, extinction, and gene flow that will help inform future conservation decisions.

evolutionary biology↗

Does breeding season variation affect evolution of a sexual signaling trait in a tropical lizard clade?

Sexually selected traits can be expected to increase in importance when the period of sexual behavior is constrained, such as in seasonally restricted breeders. Anolis lizard male dewlaps are classic examples of multifaceted signaling traits, with demonstrated reproductive function reflected in courtship behavior. Fitch and Hillis found a correlation between dewlap size and seasonality in mainland Anolis using traditional statistical methods. Here, we present two tests of the Fitch-Hillis Hypothesis using new phylogenetic and morphological data sets for 44 species of Mexican Anolis. A significant relationship between dewlap size and seasonality is evident in phylogenetically uncorrected analyses but erodes once phylogeny is accounted for. This loss of statistical support for a relationship between a key aspect of dewlap morphology and seasonality also occurs within a species complex (A. sericeus group) that inhabits seasonal and aseasonal environments. Our results fail to support seasonality as a strong driver of evolution of Anolis dewlap size. We discuss the implications of our results and the difficulty of disentangling the strength of single mechanisms on trait evolution when multiple selection pressures are likely at play.

evolutionary biology↗