Snakes experienced a sudden burst of evolution after dinosaurs were wiped out 66 million years ago — their diets expanded to include birds, fish and small mammals, study finds
- Snakes had a sudden burst of evolution after THE dinosaurs were wiped out
- they expanded their diet to include birds, fish and small mammals
- This rapid diversification of snakes led to the nearly 4,000 species we see today
- Scientists studied diets of living snakes and model reconstructed what ancestors ate
It is known that the demise of the dinosaurs 66 million years ago led to a remarkable diversification of mammals and birds on Earth.
But a new study has found that snakes also went through an equally spectacular burst of evolution, expanding their diets from insects and lizards to the newly available fish, birds and small mammals.
This rapid change led to the nearly 4,000 species we see today, according to researchers at the University of California and University of Michigan.
To better understand how this evolution happened, experts studied the diets of 882 living snake species and used mathematical models to reconstruct how their ancestors’ diets changed and diversified after a giant asteroid hit Earth.
They found that the most recent common ancestor of living snakes was insectivorous — consuming only insects and worms — but after the Cretaceous-Paleogene extinction, the snake’s diet quickly expanded to include vertebrate groups that also flourished in the wake of the extinction of the dinosaurs.
Snakes experienced a massive burst of evolution after the dinosaurs were wiped out, a new study has found, expanding their diets to include the newly available fish, birds and small mammals
This rapid diversification led to the nearly 4,000 species we see today, according to experts at the University of California and the University of Michigan. Pictured is a green vine snake
ARE PEOPLE BORN WITH A FEAR OF SNAKES & Spiders?
Researchers from MPI CBS in Leipzig, Germany and Uppsala University in Sweden conducted a study which showed that even infants experience a stress response when they see a spider or snake.
They found that this happens as early as six months old, when babies are still very immobile and haven’t had much opportunity to learn that these animals can be dangerous.
“When we showed the babies pictures of a snake or spider instead of a flower or fish of the same size and color, they reacted with significantly larger pupils,” says Stefanie Hoehl of the University of Vienna.
The researchers concluded that the fear of snakes and spiders is of evolutionary origin, and like primates or snakes, mechanisms in our brain allow us to identify objects and react to them very quickly.
“Much of the astonishing ecological diversity in snakes appears to be the result of evolutionary explosions caused by ecological opportunity,” said lead author Michael Grundler of the University of California.
“We found a major burst of snake diet diversification after the extinction of the dinosaurs — species evolved rapidly and quickly acquired the ability to eat new types of prey.”
Researchers said similar bursts of food diversification were also seen when snakes arrived in new places, including when they colonized the “New World.”
“This suggests that snakes take advantage of opportunities in ecosystems,” said study co-author Daniel Rabosky of the University of Michigan.
“Sometimes those opportunities are created by extinction, and sometimes they’re caused by an old snake spreading to a new landmass.”
Dietary diversification in snakes slowed after the initial explosion, but some genera experienced further bursts of adaptive evolution, the study concluded.
For example, colubroid snakes diversified as Old World ancestors colonized the Americas.
These findings show that mass extinctions and new biogeographic opportunities can drive evolutionary change, the authors said.
Because snake fossils are rare, direct observation of the ancient ancestors of modern snakes — and the evolutionary relationships between them — is mostly hidden from view.
Researchers said similar bursts of food diversification were also seen when snakes arrived in new places, including when they colonized the ‘New World’
Diet diversification in snakes slowed after initial blast, but some genera experienced further bursts of adaptive evolution, study concluded
However, those relationships are preserved in the DNA of living snakes. Biologists can extract that genetic information and use it to construct family trees, which biologists call phylogenies.
Grundler and Rabosky merged their nutritional dataset with previously published snake phylogenetic data in a new mathematical model that allowed them to deduce how long extinct snake species had been.
“You would think it would be impossible to know things about species that lived long ago that we don’t have fossil information about,” Rabosky said.
“But if we have information about evolutionary relationships and data about species living today, we can use these advanced models to estimate what their ancestors were like long ago.”
The new research is published in the journal PLOS Biology.
REDUCE DINOSAURS: HOW A CITY SIZE ASTEROID DESTROYS 75 PERCENT OF ALL ANIMAL AND PLANT SPECIES
About 66 million years ago, non-avian dinosaurs were wiped out, wiping out more than half of the world’s species.
This mass extinction paved the way for the rise of mammals and the appearance of humans.
The Chicxulub asteroid is often cited as a possible cause of the Cretaceous-Paleogene extinction.
The asteroid slammed into a shallow sea in what is now the Gulf of Mexico.
The collision released a huge cloud of dust and soot that caused global climate change and wiped out 75 percent of all animal and plant species.
Researchers argue that the soot needed for such a global catastrophe could only come from a direct impact on rocks in shallow water around Mexico, which are particularly rich in hydrocarbons.
Within 10 hours of the impact, a massive tsunami ripped through the Gulf Coast, experts believe.
About 66 million years ago, non-avian dinosaurs were wiped out, wiping out more than half of the world’s species. The Chicxulub asteroid is often cited as a possible cause of the Cretaceous-Paleogene extinction (stock image)
This caused earthquakes and landslides in areas as far as Argentina.
While investigating the event, researchers found small particles of rock and other debris that were shot into the sky when the asteroid crashed.
These tiny particles, called spherules, covered the planet with a thick layer of soot.
Experts explain that the loss of light from the sun caused a complete collapse of the water system.
This is because the phytoplankton base of almost all aquatic food chains would have been eliminated.
It is believed that the more than 180 million years of evolution that brought the world to the Cretaceous Period were destroyed in less than the lifespan of a Tyrannosaurus rex, which is about 20 to 30 years.