Modern snakes ‘evolved from a few survivors of dinosaur-killing asteroid’

All living snakes evolved from a handful of species that survived the giant asteroid impact that wiped out the dinosaurs, a study suggests.

Researchers say the devastating extinction event at the end of the Cretaceous was a form of creative destruction that allowed snakes to diversify into new niches, previously filled by their competitors.

Snakes today, including almost 4,000 living species, started to diversify around the time that an extraterrestrial impact wiped out the dinosaurs and most other species on the planet, according to the study.

Scientists at the University of Bath and collaborators from Bristol, Cambridge and Germany used fossils and analysed genetic differences between modern snakes to reconstruct their evolution.

The analysis helped to pinpoint the time modern snakes evolved.

The results suggest that all living snakes trace back to a handful of species that survived the asteroid impact 66 million years ago, which wiped out the dinosaurs.

Lead author Dr Catherine Klein, who now works at Friedrich-Alexander-Universitat Erlangen-Nurnberg (FAU) in Germany, said: “It’s remarkable, because not only are they surviving an extinction that wipes out so many other animals, but within a few million years they are innovating, using their habitats in new ways.”

The researchers say the ability of snakes to shelter underground and go for long periods without food helped them survive the destructive effects of the impact.

The extinction of their competitors allowed snakes to move into new niches, new habitats and new continents.

They began to diversify, producing lineages like vipers, cobras, garter snakes, pythons and boas, exploiting new habitats and new prey.

The study also suggests snakes began to spread across the globe around this time.

Dr Nick Longrich, from the Milner Centre for Evolution at the University of Bath and the corresponding author, said: “Our research suggests that extinction acted as a form of creative destruction – by wiping out old species, it allowed survivors to exploit the gaps in the ecosystem, experimenting with new lifestyles and habitats.

“This seems to be a general feature of evolution – it’s the periods immediately after major extinctions where we see evolution at its most wildly experimental and innovative.

“The destruction of biodiversity makes room for new things to emerge and colonise new landmasses.

“Ultimately life becomes even more diverse than before.”

The new study is published in Nature Communications.