Range size evolution in gymnophthalmid lizards

Submitted by editor on 17 June 2016. Get the paper!

By Agus Camacho 

Changes of just a few centimeters in the length of a limb, or of some grams in body weight, may correlate with changes in geographic range size of thousands of square kilometers. These striking relationships may have the key to understand why some species inherently persist under extinction risk due to having small ranges. Understanding this issue imposes several challenges, like measuring the morphology of many species, estimating their phylogenetic relationships and distribution, and accounting for our uncertainty in these estimations. We developed a statistical system to account for these uncertainties and tested whether body size or shape was more correlated with range size in a number of neotropical species of gymnophthalmid lizards. These lizards represent dramatic changes in body size and shape (see the picture). Our results suggest for first time in that animal group that body size and not shape is the major morphological driver of range size.