Mammoths in North America had a surprising secret: they often interbred. New fossil evidence shows that these Ice Age giants were not just isolated species but linked in unexpected ways.
Traditionally, the woolly mammoth and the Columbian mammoth were seen as separate. The woolly mammoth roamed the colder regions of what is now Canada and northern USA, while the Columbian mammoth lived further south. Scientists thought they adapted to different environments and didn’t cross paths much.
However, a recent analysis of two fossilized teeth unearthed in Canada has changed that view. Genetic tests indicated these teeth belonged to hybrid mammoths formed from both species. This suggests that during glacial periods, woolly mammoths moved south, where they mingled and bred with their Columbian cousins.
One fossil, dating back about 25,000 years, revealed more Columbian mammoth DNA (35%) than the older one (21%) from around 36,000 years ago. This evidence suggests that these mammoth species interbred repeatedly over thousands of years.
Professor Adrian Lister, a co-author of the study, emphasized that hybridization plays a significant role in evolution. He stated, “Many species have arisen this way, which challenges the standard idea of evolution as a branching tree.” Instead of just diverging, species can also cross paths, creating new branches in the evolutionary tree.
Interestingly, analysis of the hybrids’ sex chromosomes indicated most encounters involved male Columbian mammoths mating with female woolly mammoths.
This research builds on a 2021 study where scientists found evidence of hybrids in Siberia. That study uncovered the oldest mammoth DNA, suggesting a similar pattern of interbreeding among ancient species. Increased genetic diversity from hybridization could improve a species’ ability to adapt, a crucial factor during environmental shifts.
Understanding how mammoths adapted to their changing world might offer valuable insights for modern species, like elephants. “By reconstructing their history, we may better grasp how they coped with climate changes,” said Lister. This understanding is pivotal today as we engage with our environment.
The findings have sparked interest, with discussions on social media highlighting the unexpected connections between ancient species. As more research unfolds, these revelations could reshape our understanding of evolution itself.
For a deeper dive, check the study published in Biology Letters, and learn more at Natural History Museum.
