A massive asteroid impact 66 million years ago drastically changed life on Earth, marking the end of non-avian dinosaurs and paving the way for other species to thrive. The catastrophe led to the emergence of birds, which diversified into the numerous species we see today. Scientists have now discovered genetic signatures in bird DNA that date back to this event, providing a unique window into the past.
By analyzing the DNA of living birds, researchers found dramatic changes in their genomes that occurred shortly after the mass extinction event. These changes are linked to the size of adult birds, their metabolism, and how they develop as hatchlings. For instance, adult birds became significantly smaller than their dinosaur ancestors, and there was a shift towards smaller, weaker babies that required intense parental care.
The study reveals that the asteroid impact’s effects on DNA composition were profound, influencing the biology of organisms even more dramatically than previously thought. The research highlights the significance of mass extinction events in shaping the evolution of life on Earth, emphasizing that the one that wiped out dinosaurs was a pivotal moment in our planet’s history.
Source: https://www.sciencealert.com/traces-of-dinosaur-catastrophe-found-in-genes-of-todays-birds