Global biogeography of geckos (Squamata: Gekkota) reveals Old-World origins and region-specific heterogeneity in diversification

Abstract

Aim Investigating the biogeography and diversification dynamics of global radiations to understand how Earth history has influenced lineage proliferation has long been a goal of macroevolutionary biology. Gecko lizards, being an ancient and globally distributed hyperdiverse lineage, are an excellent system to elucidate how certain regions and events have shaped observed diversity. In this study, we attempt to identify: 1) The heterogeneity in diversification rate across geckos; 2) the ancestral region of geckos; 3) if diversification rate is tied to biogeographic region; and 4) potential mass extinction events in geckos. We generated a massive supermatrix of geckos from Sanger data and, after combination with phylogenomic data, estimate the most comprehensive phylogenetic estimate of geckos to date with 1,783 species. We performed fossil informed ancestral area reconstructions to evaluate the impact of fossils. We performed both state-dependent and state-agnostic diversification analyses to access diversification dynamics. Lastly, we tested for clade-wide mass extinction events. Our divergence date estimates suggested a Jurassic origin for pan-Gekkota and a Cretaceous origin for crown Gekkota. We recovered an Old-World origin for crown Gekkota with high uncertainty and an African origin for the families Phyllodactylidae, Sphaerodactylidae, and Gekkonidae with high confidence. Our results suggest differential diversification dynamics between pygopodoid (Australasian) and gekkonoid lineages (cosmopolitan), with the latter experiencing overall higher rates and more heterogeneity. Our results further suggest Africa being a biodiversity refugia while Eurasia acted as a diversification hotspot for geckos. Lastly, we find no evidence that crown geckos experienced any mass extinctions despite surviving the K-Pg event and major climatic oscillations during the Cenozoic. Our study provides an important global view for the biogeographic and diversification patterns of a morphologically and ecologically distinct lineage of lizards, setting the stage for studies placing clade-specific histories in a global context.