How Snakes Scaled Evolutionary Heights

MORE THAN 100 MILLION YEARS ago, the ancestors of the first snakes were small lizards that lived alongside other small, nondescript lizards in the shadow of the dinosaurs. Then, in a burst of innovation in form and function, snakes experienced one of the most dramatic evolutionary shifts of all time. They rapidly developed elongated legless bodies that could slither across the ground, climb into trees, burrow under the earth and crawl along the seabed. They acquired flexible skulls that enabled them to swallow large animals. Their habitats expanded. Their diets grew.

A research team that included Associate Professor of Biology

Alexander Pyron completed a decade-long project that constructed the most comprehensive evolutionary tree of snakes and lizards ever. The study presents a vivid picture of how snakes evolved faster and with more variety than other species.

“We thought maybe the [snakes] would show something exceptional in one area but maybe not in another,” Pyron noted. “But, no, it’s every single thing—increased rates of body form evolution, increased rates of diet evolution, increased rates of niche evolution. Snakes stand out as a huge cut above every other group of lizards.”