Anolis

circa 425 spp., see text Anolis is a genus of anoles (US: /əˈnoʊ.liz/ ⓘ), iguanian lizards in the family Dactyloidae, native to the Americas.

[2][3] Previously, it was classified under the family Polychrotidae that contained all the anoles, as well as Polychrus, but recent studies place it in the Dactyloidae.

[2] This very large genus displays considerable paraphyly, but phylogenetic analysis suggests a number of subgroups or clades.

Populations of lizards on isolated islands diverge to occupy separate ecological niches, mostly in terms of the location within the vegetation where they forage (such as in the crown of trees vs. the trunk vs. underlying shrubs).

Each new species developed its own distinct body type, called an ecomorph, adapted to the tree niche where it lived.

Four modern ecomorph body types, trunk-crown, trunk-ground, trunk, and twig, are represented in the amber fossils study.

[18] On the island of Hispaniola, both high-altitude and low-altitude lizard populations exist, and the thermal conditions at high and low elevations differ significantly.

To escape dangers, species that evolved near water have adapted the ability to stay submerged for as long as 18 minutes.

[20] The Anolis lizards that are less susceptible to predation are those with a dewlap in which both the scales and the exposed skin areas between them match the usual pale gray or whitish of the rest of the ventral surface.

They determined this by measuring the amount of times a "positive response" of the lizard's eyes turning towards a flashed dewlap occurred among different background contrasts.

Similarly, Leal and Fleishman (2002) found that the light conditions in which a lizard displays its dewlap affects the probability of it being visually detected.

Anolis lizards have the ability to adapt to different areas of the environment in a way where multiple species can coexist effectively.

[29] This causes a genetic homogenization and challenges the idea that dewlap morphology in Anolis lizards and their sensory systems have coevolved.

Pink dewlap on an Anolis carolinensis lizard