All living snakes evolved from a few species that survived the massive asteroid impact that wiped out the dinosaurs and most other living things at the end of the Cretaceous period. Credit: Joschua Knuppe
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Research from the Milner Center for Evolution suggests that modern snakes evolved from a handful of ancestors who survived the asteroid that killed the dinosaurs.
A new study suggests that all living snakes evolved from a few species that survived the impact of the giant asteroid that wiped out the dinosaurs and most other living things at the end of the world.
Search published in Natural Connection, suggesting that snakes, including today’s nearly 4,000 living species, began to diversify around the time the space impact wiped out the dinosaurs and most of the other species on the planet.
The research, led by scientists at the University of Bath and including collaborators from Bristol, Cambridge and Germany, used fossils and analyzed genetic differences between modern snakes to reconstruct snake evolution. The analysis helped determine when modern snakes evolved.
Their results show that all living snakes belong to the few species that survived the asteroid impact 66 million years ago, the same extinction that wiped out the dinosaurs.
The authors argue that the snakes’ ability to burrow underground and go for long periods without food helped them survive the devastating impact. After that, the extinction of their rivals—including the Cretaceous snakes and the dinosaurs themselves—allowed the snakes to move into new niches, new habitats, and new continents.
Then the snakes began to diversify, producing subspecies such as rattlesnakes, cobras, garter snakes, pythons, and boas, exploiting new habitats, and new prey. The diversity of modern snakes—including tree snakes, sea snakes, rattlesnakes and cobras, as well as large eels such as boas and pythons—appeared only after the extinction of the dinosaurs.
The fossils also show changes in the shape of the snake’s spine following the extinction of the Cretaceous lineage and the emergence of new groups, including giant sea snakes up to 10 meters in length.
“This is remarkable, because not only did they survive the extinction that wiped out many other animals, but within a few million years they innovated, using their habitat in new ways,” said lead author and recent graduate student at the University of Bath, Dr. . at Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU) in Germany.
The study also shows that snakes began to spread around the world around this time. Although the ancestors of living snakes may have lived somewhere in the southern hemisphere, snakes appear to have spread to Asia after the extinction.
Dr Nick Longrich, from the University of Bath’s Milner Evolution Center and related authors said: “Our research shows that extinctions are a form of ‘creative destruction’ – by removing ancient species, it allows survivors to exploit gaps in ecosystems, and experiment with lifestyles and habitats. new.
“This seems to be a common feature of evolution – this is the period immediately after the great extinctions where we see evolution at its most experimental and innovative state.
“The destruction of biodiversity paved the way for new things to emerge and colonize new territories. Finally life is more diverse than before.”
The study also found evidence of a second major diversification event around the time when the world shifted from a warm ‘greenhouse’ to a cold ‘icehouse’ climate, which saw the formation of polar ice sheets and the onset of ice ages.
The patterns seen in snakes suggest a key role for disasters – severe, rapid and global environmental disturbances – in driving evolutionary change.
Reference: “Evolution and dispersal of snakes through Cretaceous and Paleogene mass extinctions” by Catherine J. Klein, David Pisani, Daniel J. Field, Rebecca Lakin, Matthew A. Wells, and Nicholas R. Longrich, September 14, 2021, Natural Connection.
DOI: 10.1038 / s41467-021-25136-y
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