Researchers in Puerto Rico found that in urban habitats, crested anole lizards have more scales on their toes and larger toepads that help them grip surfaces compared with anoles in the native forest habitat. The researchers estimated that this anole population had been exposed to urban environments for 30–40 years, which corresponds to 100 or more lizard generations. What hypothesis might explain this observation?

The hypothesis that might explain this observation is that anoles, as a result of the slickness of walls and windows, are evolving adaptive features to enable them to fast adapted to grip urban smooth surfaces which are quite different from surfaces of trees in their native forest habitat. Structures such as larger toepads and toes with more scales, are adaptive features they have evolved overtime from generation to generation, making them different from anoles found in native forest habitat.