Data from: Rapid evolution of a native species following invasion by a congener

In recent years, biologists have increasingly recognized that evolutionary
change can occur rapidly when natural selection is strong; thus, real-time
studies of evolution can be used to test classic evolutionary hypotheses
directly. One such hypothesis is that negative interactions between
closely related species can drive phenotypic divergence. Such divergence
is thought to be ubiquitous, though well-documented cases are surprisingly
rare. On small islands in Florida, we found that the lizard Anolis
carolinensis moved to higher perches following invasion by Anolis sagrei
and, in response, adaptively evolved larger toepads after only 20
generations. These results illustrate that interspecific interactions
between closely related species can drive evolutionary change on
observable time scales.