Animal genomes are known to be a storage space of memories. Perhaps the phrase ‘etched in memory’ had a real meaning after all. A new study has found that genomes of birds have markers that store the memories of the cataclysm that caused the extinction of their dinosaur ancestors. These genetic markers helped them evolve and survive over millennia, and flourish into more than 10,000 species.
The University of Michigan study found that the mass extinction of dinosaurs paved the way for rapid changes in bird genomes.
How the study was done
Published in Science Advances, the study found evidence of ‘genomic fossils’ in bird DNA that will help shed light on how birds evolved.
“By studying the DNA of living birds, we can try to detect patterns of genetic sequences that changed just after one of the most important events in Earth’s history,” said lead author Jake Berv, referring to the asteroid strike 66 million years ago that’s thought to have wiped out the dinosaurs.
“The signature of those events seems to have imprinted into the genomes of the survivors in a way that we can detect tens of millions of years later,” Berv said.
According to the researchers, the mass extinction of dinosaurs sparked shifts in nucleotide composition in the genomes of birds.
These shifts “seem to be connected to the way birds develop as babies, their adult size and their metabolism,” said a release from Michigan University.
Their development also changed, showing ‘altricial’ pattern. An altricial animal is “very embryonic when they hatch, need their parents to feed them, and can take weeks to fledge,” Berv said. This is opposed to ‘precocial’, referring to species that are ready to fend for themselves the moment they’re born, like chickens and turkeys.
The study stresses how extinction events can influence biology of organisms by altering important aspects of how genomes evolve.
“This work furthers our understanding of the dramatic biological impacts of mass extinction events and highlights that the mass extinction that wiped out the giant dinosaurs was one of the most biologically impactful events in the entire history of our planet,” said Daniel Field, professor of vertebrate palaeontology at the University of Cambridge and co-author of the study.
(With inputs from agencies)
Shambhu Kumar is a science communicator, making complex scientific topics accessible to all. His articles explore breakthroughs in various scientific disciplines, from space exploration to cutting-edge research.
