Phylogeographic and phenotypic outcomes of brown anole colonization across the Caribbean provide insight into the beginning stages of an adaptive radiation

Abstract

Some of the most important insights into the ecological and evolutionary processes of diversification and speciation have come from studies of island adaptive radiations, yet relatively little research has examined how these radiations initiate. We suggest that Anolis sagrei is a candidate for understanding the origins of the Caribbean Anolis adaptive radiation and how a colonizing anole species begins to undergo allopatric diversification, phenotypic divergence and, potentially, speciation. We undertook a genomic and morphological analysis of representative populations across the entire native range of A. sagrei, finding that the species originated in the early Pliocene, with the deepest divergence occurring between western and eastern Cuba. Lineages from these two regions subsequently colonized the northern Caribbean. We find that at the broadest scale, populations colonizing areas with fewer closely related competitors tend to evolve larger body size and more lamellae on their toepads. This trend follows expectations for post‐colonization divergence from progenitors and convergence in allopatry, whereby populations freed from competition with close relatives evolve towards common morphological and ecological optima. Taken together, our results show a complex history of ancient and recent Cuban diaspora with populations on competitor‐poor islands evolving away from their ancestral Cuban populations regardless of their phylogenetic relationships, thus providing insight into the original diversification of colonist anoles at the beginning of the radiation. Our research also supplies an evolutionary framework for the many studies of this increasingly important species in ecological and evolutionary research.

Chromosome-scale genome assembly of the brown anole (Anolis sagrei), a model species for evolution and ecology

“…Anolis sagrei is a medium-sized insectivorous lizard most commonly found on the ground and perched low on the trunks of trees 20 . Although it first arose on Cuba, the species now has the largest native range of any anole with natural diaspora populations found across islands of the northern Caribbean as well as coastal areas of Mesoamerica 21,22 . It is also a prolific invader with non-native populations established on many additional islands in the West Indies 23,24 , Costa Rica, multiple locations in both North 25 and South America 26,27 , as well as remote islands of the central Atlantic Ocean 28,29 , Hawaii 30 , Taiwan, and mainland Asia, Europe, and the Middle East.…”

Establishment of brown anoles (Anolis sagrei) across a southern California county and potential interactions with a native lizard species

“…The brown anole, Anolis sagrei, is a recently reported invasive species to California (Mahrdt, Ervin & Nafis, 2014). While this species is a native to Cuba, The Bahamas, additional Caribbean islands and eastern Mesoamerica, A. sagrei has also recently invaded Taiwan likely by way of the plant trade (Norval et al, 2016;Reynolds et al, 2020). The invasion in Taiwan is increasingly widespread and eradication is seemingly no longer an effective option (Norval et al, 2016).…”

“…The invasion in Taiwan is increasingly widespread and eradication is seemingly no longer an effective option (Norval et al, 2016). Other countries invaded by A. sagrei include Anguilla, Bermuda, Grand Cayman, Ecuador, Grenada, Jamaica, Mexico (even though it is native on the east coast), Singapore, St. Vincent and Turks and Caicos (Kraus, 2009;Amador et al, 2017;Reynolds et al, 2020). In the USA, A. sagrei has invaded multiple states, including Florida, Louisiana, Texas and Hawai'i (Kolbe et al, 2004;Kraus, 2009).…”

Peer Review #2 of "Establishment of brown anoles (Anolis sagrei) across a southern California county and potential interactions with a native lizard species (v0.1)"

“…The invasion in Taiwan is increasingly widespread and eradication is seemingly no longer an effective option (Norval et al, 2016). Other countries invaded by A. sagrei include Anguilla, Bermuda, Grand Cayman, Ecuador, Grenada, Jamaica, Mexico (even though it is native on the east coast), Singapore, St. Vincent, and Turks and Caicos (Kraus 2009;Amador et al, 2017;Reynolds et al, 2020). In the United States, A. sagrei has invaded multiple states, including Florida, Louisiana, Texas, and Hawai'i (Kolbe et al, 2004;Kraus, 2009).…”