Extinct Yak Species Found

Researchers at Stockholm University have identified a previously unknown extinct bovine species, currently known as yak X, in Siberia's Denisova Cave. The team, led by Love Dalén, began studying bone fragments from the cave to learn about bison evolution, but found that nearly all the fragments had DNA that didn't match any living bovine species.

The species is believed to have diverged from the wild yak around 400,000 years ago and became genetically isolated by 250,000 years ago. It is thought to have gone extinct around 30,000 years ago.

The discovery was made possible by analyzing hundreds of tiny bone fragments from the cave and other nearby sites. The team was able to construct genomes from 20 individuals, which showed that yak X was a distinct species that didn't interbreed with other bovines in the area.

According to Alexandre Gilardet, a study co-author, the divergence of yak X from modern yaks is similar to the divergence between polar bears and brown bears. This suggests that yak X was a unique species that was adapted to its environment in southern Siberia.

The discovery of yak X highlights the Altai region as a possible biodiversity hotspot and refugium across Ice Ages, according to Love Dalén. The team's findings are published in the journal Current Biology.

Jonas Oppenheimer, a study co-author, notes that the long time span of the dataset allows researchers to look across whole glacial cycles to see how they might have impacted the species. The team's research provides new insights into the evolution of bovine species and the impact of climate change on their populations.

The bones found so far are much lower in elevation than the native range of modern yaks, suggesting that yak X may have been less adapted to extreme mountain environments. Further research is needed to determine the unique traits of yak X and how it lived in its environment.