Bird genomes hold clues to dinosaur extinction, reveals study
A recent study has unveiled that bird genomes harbor markers storing memories of the mass extinction event that wiped out dinosaurs from Earth. Conducted by the University of Michigan, the research found these genetic markers have significantly contributed to bird evolution and survival. Published in Science Advances, the study suggests these "genomic fossils" led to rapid changes in bird genomes post-dinosaur extinction, offering insights into avian evolution.
DNA analysis sheds light on bird evolution post-dinosaur era
Lead author Jake Berv explained the significance of studying bird DNA in understanding Earth's history. He explained that by examining the DNA of living birds, researchers can identify genetic sequence patterns that shifted following one of Earth's most significant events. Berv was referring to the asteroid strike 66 million years ago believed to have caused dinosaur extinction. He further added that these events seem to have left a detectable imprint on the genomes of surviving species millions of years later.
Extinction event triggered shifts in bird genomes
The research team discovered that the mass extinction event caused shifts in nucleotide composition within bird genomes. According to a release from the University of Michigan, these shifts "seem to be connected to the way birds develop as babies, their adult size and their metabolism." Post the asteroid strike 66 million years ago, surviving bird lineages tended to develop smaller body sizes and shifted toward an "altricial" pattern of development.
Extinction events influence organism biology
The study underscores how extinction events can profoundly affect organism biology by modifying key aspects of genome evolution. Co-author Daniel Field, a professor of vertebrate paleontology at the University of Cambridge, noted that this research advances our understanding of the profound biological effects of mass extinction events. He emphasized that the mass extinction that eradicated the giant dinosaurs was one of the most biologically impactful events in Earth's history.
Decoding bird evolution through genomic research
Berv explains that one of the biggest challenges in evolutionary ornithology is unraveling the relationships between major bird groups, making it difficult to map the tree of life for birds. Over the past 15 years, researchers have used increasingly large genomic data sets to tackle this issue. Traditionally, they relied on statistical models that assume the composition of DNA—specifically the proportions of A, T, G, and C nucleotides—remains constant throughout evolutionary history, allowing them to reconstruct genetic changes over time.
