Snakes benefited from the mass extinction after the asteroid impact 66 million years ago. The asteroid impact wiped out 95 percent of all life on Earth, including the dinosaurs, and only a few species of snake survived. The lack of predators and their ability to survive for long periods without food helped snakes to spread to other continents and exploit new habitats, allowing a wide variety of new species to develop. The patterns seen in snakes show that natural disasters play a greater role in evolution than previously thought.