Phylogeography of a widespread lizard complex reflects patterns of both geographic and ecological isolation

Abstract

A primary challenge for modern phylogeography is understanding how ecology and geography, both contemporary and historical, shape the spatial distribution and evolutionary histories of species. Phylogeographic patterns are the result of many factors, including geology, climate, habitat, colonization history and lineage‐specific constraints. Assessing the relative influences of these factors is difficult because few species, regions and environments are sampled in enough detail to compare competing hypotheses rigorously and because a particular phylogeographic pattern can potentially result from different evolutionary scenarios. The silky anoles (Anolis sericeus complex) of Central America and Mexico are abundant and found in all types of lowland terrestrial habitat, offering an excellent opportunity to test the relative influences of the factors affecting diversification. Here, we performed a range‐wide statistical phylogeographic analysis on restriction site‐associated DNA (RAD) markers from silky anoles and compared the phylogeographic patterns we recovered to historical and contemporary environmental and topographic data. We constructed niche models to compare niche overlap between sister lineages and conducted coalescent simulations to characterize how the major lineages of silky anoles have diverged. Our results revealed that the mode of divergence for major lineage diversification events was geographic isolation, resulting in ecological divergence between lineages, followed by secondary contact. Moreover, comparisons of parapatric sister lineages suggest that ecological niche divergence contributed to isolation by environment in this system, reflecting the natural history differences among populations in divergent environments.

Comparative phylogeography of mainland and insular species of Neotropical molossid bats (Molossus)

“…Populations on islands are more isolated, have a smaller meta‐population size, and are more vulnerable to habitat disturbance than mainland populations, which might alter insular population structure (Leisler & Winkler, ; Losos & Ricklefs, ; Spilani et al, ). Although alternative drivers of phylogeographic and population structure have been proposed for continental (Gray et al, ; Kalkvik, Stout, Hoffman, & Parkinson, ) and island populations (Čandek, Agnarsson, Binford, & Kuntner, ), few studies have explicitly compared the patterns between these two biogeographic systems (e.g., Pons et al, ). This comparison provides an opportunity to investigate the relative role of isolation, habitat selection, and demographic history in shaping phylogeographic patterns (Kalkvik et al, ; Sexton, Hangartner, & Hoffmann, ), especially using closely related species with similar life histories.…”

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

“…The Pacific and Caribbean lineages span the most and least seasonal environments inhabited by the group and do not show a strong correlation between seasonality and dewlap size, nor do analyses of single lineages (Figure ). Individuals in the Caribbean lineage (sister to the Yucatan; Gray et al, 2019) do not have a reduced dewlap and occur in statistically indistinguishable seasonality environments (Table 1). If seasonality affects the evolution of dewlap size in silky anoles, we would expect to see reduced dewlaps in both lineages found in relatively aseasonal environments or a significant increase in dewlap size in the lineage inhabiting seasonal environments, neither of which occurs.…”

“…In Mexico, the Anolis sericeus group (silky anoles; considered by Fitch & Hillis[, 1984] to be a single species) consists of three divergent clades (referred to here as Pacific, Caribbean, and Yucatan) that may be separate species (Gray et al, 2019; Figure 1, Appendix ). A phylogenetic regression was not possible for these analyses, as molecular data are absent for a number of the sampled populations (Gray et al, 2019). We averaged male dewlap size for specimens from each locality and performed a standard OLS regression of dewlap size and head length using all silky anole localities.…”

“…Species with larger dewlaps also exhibited stronger male‐biased sexual size dimorphism, providing additional support for their hypothesis. Anolis sericeus (now considered a species complex; Gray et al, 2019; Lara‐Tufiño, Nieto‐Montes de Oca, Ramírez‐Bautista, & Gray, 2016), the one species found in both seasonal and aseasonal habitats, fit their interspecies pattern: A population they sampled from a seasonal environment possessed a larger dewlap than another from an aseasonal environment. Their findings of environmental seasonality affecting the evolution of a sexual signal could have important implications for sexual species that experience environmentally imposed restrictions on length of the breeding season.…”

Morphological evidence of sexual dimorphism in a Continental anole species of southeastern of Mexico

“…Despite this, there is little information about SD in most of the mainland Anolis species; therefore, it is necessary to determine whether SD occurs in other morphological structures beyond previously reported (Márquez et al 2005;Siliceo-Cantero et al 2016;Hernández-Salinas et al 2019). Therefore, the goal of this study is to analyze the SD of a tiny mainland anole species Anolis unilobatus Köhler and Vesely 2010; east pacific and central depression Chiapas clade see Gray et al 2019 (We will refer as Anolis unilobatus to the populations of the east pacific lineage, but we are aware of these populations belong to an evolutionarily independent lineage to the populations of the west pacific and of central America Gray et al 2019). For this, we analyzed sexual differences in eight morphological characteristics through multivariate statistics.…”