Snakes diversified due to mass extinction
Snakes benefited from the mass extinction caused by the asteroid’s impact 66 million years ago, according to a new study published by scientists at FAU, University of Bath, University from Bristol and the University of Cambridge. The asteroid impact wiped out 95% of all life on Earth, including dinosaurs, and only a few species of snakes survived. The lack of predators and their ability to survive for long periods without food has helped snakes spread to other continents and exploit new habitats, allowing a wide variety of new species to thrive. The patterns seen in snakes show that natural disasters play a bigger role in evolution than previously thought. The results were published in the journal Nature Communications.
A team of scientists led by Dr Catherine Klein, postdoctoral researcher at GeoZentrum Nordbayern at FAU, examined the fossils and genetic sequences of modern snakes and were able to determine that all snake species living today can be traced back to only five species that survived mass extinction. While the ancestors of modern snakes probably lived somewhere in the southern hemisphere, new species appear to have spread to Asia for the first time after mass extinction. The fact that several natural predators were wiped out greatly facilitated the colonization of new habitats by the snakes. By analyzing the fossils, the scientists also found that the skeletons of the snakes had changed considerably after the mass extinction. New groups have appeared, including giant sea snakes that can reach 10 meters in length. “Snakes not only survived the mass extinction that wiped out so many other species, but they also began to innovate and use their habitats in new ways,” says Dr Catherine Klein. Snakes then began to diversify and produced new species like vipers, boas, pythons and cobras over the course of several million years. Today there are more than 4000 known species of snakes.
“It appears that evolution is most experimental and innovative during the periods immediately following a mass extinction event, which is why we might view extinction as a form of ‘creative destruction’,” says Dr. Nicholas Longrich, co-author of the University of Bath. Species are wiped out and survivors can use ecosystem gaps and exploit new habitats and lifestyles. It makes life even more diverse than before.