Influence of niche breadth and position on the historical biogeography of seafaring scincid lizards

Biological Journal of the Linnean Society
By: , and 



Niche breadth and position can influence diversification among closely related species or populations, yet limited empirical data exist concerning the predictability of the outcomes. We explored the effects of these factors on the evolution of the Emoia atrocostata species group, an insular radiation of lizards in the western Pacific Ocean and Indo-Australasia composed of both endemic and widespread species that differ in niche occupancy. We used molecular data and phylogeographical diffusion models to estimate the timing and patterns of range expansion, and ancestral reconstruction methods to infer shifts in ecology. We show evidence of multidirectional spread from a centre of origin in western Micronesia, and that the phyletic diversity of the group is derived from a putative habitat specialist that survives in the littoral zone. This species is composed of paraphyletic lineages that represent stages or possible endpoints in the continuum toward speciation. Several descendant species have transitioned to either strand or interior forest habitat, but only on remote islands with depauperate terrestrial faunas. Our results suggest that the atrocostata group might be in the early phases of a Wilsonian taxon cycle and that the capacity to tolerate salt stress has promoted dispersal and colonization of remote oceanic islands. Divergence itself, however, is largely driven by geographical isolation rather than shifts in ecology.

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Publication type Article
Publication Subtype Journal Article
Title Influence of niche breadth and position on the historical biogeography of seafaring scincid lizards
Series title Biological Journal of the Linnean Society
DOI 10.1093/biolinnean/blaa172
Volume 132
Issue 1
Year Published 2021
Language English
Publisher Oxford Academic
Contributing office(s) Western Ecological Research Center
Description 19 p.
First page 74
Last page 92
Country Australia
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