A groundbreaking study has revealed that the evolution of modern birds began much earlier than previously thought, predating the mass extinction event that wiped out the dinosaurs. This discovery challenges long-held beliefs about the rapid diversification of bird species following the dinosaurs’ demise.
Published in the Proceedings of the National Academy of Sciences, the research was conducted by an international team of scientists from the Chinese mainland and the United States. Analyzing the genomes of 124 living bird species, they constructed an evolutionary tree for Neoaves—a group that encompasses 95 percent of all modern birds.
By combining genetic data with fossil records, the researchers identified that the main lineages of birds split into two distinct groups during the Late Cretaceous period, approximately 87 million years ago. One group consisted of land-based species, while the other comprised waterbirds. This division occurred well before the end-Cretaceous mass extinction event, around 66 million years ago, that led to the downfall of dinosaurs.
“Our findings suggest that the extinction event seems to have had a limited impact on birds’ evolution,” explained Professor Wu Shaoyuan from Jiangsu Normal University in the Chinese mainland, the study’s first author. “The development of modern birds is a gradual and continuous process driven by natural selection.”
The study further revealed that a global warming event 55 million years ago played a significant role in the evolution of modern seabird species, such as penguins and seagulls. This period of climatic change provided new ecological niches and resources, facilitating the diversification of these species.
Co-author Professor Zhou Zhonghe from the Institute of Vertebrate Paleontology and Paleoanthropology at the Chinese Academy of Sciences emphasized the broader implications of the findings. “The evolution of birds aligns with the diversification patterns of plants, mammals, fish, and insects,” he noted. “It provides a more comprehensive perspective on how life’s diversity gradually unfolded on Earth.”
This research not only reshapes our understanding of avian evolution but also offers valuable insights into how species adapt and diversify over extended periods. For academics, researchers, and enthusiasts alike, these findings underscore the intricate and long-term processes that have shaped the natural world as we know it today.
Reference(s):
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