A new study argues that the evolution of modern birds began much earlier than previously thought, before the extinction of the dinosaurs, Xinhua reported on Monday, citing Agerpres.

The study, published earlier this month in the journal Proceedings of the National Academy of Sciences, was coordinated by researchers from China and the United States, who analyzed the genomes of 124 bird species and created an evolutionary tree of Neoaves, a group that includes 95% of birds. modern birds

Combining the data obtained from the study of fossils, they came to the conclusion that the main evolutionary lines of birds can be divided into two groups: one group represents land birds, and the other – waterfowl.

They estimate that this split occurred during the Late Cretaceous (about 87 million years ago), long before the extinction of the dinosaurs at the end of the Cretaceous period, 66 million years ago.

Toward a paradigm shift in bird evolution?

The conclusion of the new study contradicts the hypothesis widespread in scientific circles, according to which the disappearance of dinosaurs was followed by the rapid evolution of bird species. Previous studies have shown that the extinction of the dinosaurs led to the spread and diversification of bird species that no longer faced the competition for food resources that the dinosaurs did in the ecosystem, reaching 11,000 bird species today.

The extinction of the dinosaurs “seems to have had a limited impact on the evolution of birds,” says study coordinator Wu Shaoyuan, a professor at Jiangsu University in eastern China.

The researchers also found that global warming that occurred on Earth 55 million years ago is responsible for the evolution of modern seabird species such as penguins and seagulls. The new findings offer a more sophisticated and easier-to-understand perspective on bird evolution, says co-author Zhou Zhonghe of the Institute of Vertebrate Paleontology and Paleoanthropology of the Chinese Academy of Sciences.

“The evolution of modern birds, unlike the previously accepted model of rapid evolutionary change, is a gradual and continuous process determined by natural selection,” Zhou noted.