Search form

University of Virginia UVA Arts & Sciences Default

Survival of the Fattest? Not in the Brown Anole

Nov 17, 2014 |
Amy Zhang

Darwinian natural selection is often described as the survival of the fittest. However, determining which individuals are actually the fittest can be challenging, so biologists often use proxies in place of fitness. One popular proxy is body condition: the mass of an animal relative to its size or length. But is “fatter” really “fitter” in nature?

To answer this question, Robert Cox (UVA) and Ryan Calsbeek (Dartmouth College) analyzed a decade of survival records for over 4,600 brown anole lizards across seven populations in The Bahamas. Their study, recently published in Functional Ecology,revealed that fatter is not fitter, at least when it comes to survival. In fact, the only time that “fatter is fitter” seems to hold true is for the largest males in the population, who experience an extra boost in their probability of survival if they are also in high condition.

Read the published article here.