When analyzing the DNA of 14 animals of the species, researchers found that the population of woolly rhinos was stable even after the arrival of humans in Siberia.
The woolly rhinoceros is an extinct species that lived in Europe and northern Asia during the Ice Age. Its extinction has often been attributed to the spread of the first humans across the globe.
However, new research published in the journal Current Biology suggests that the species may have disappeared because of climate change.
“It was initially thought that humans appeared in northeastern Siberia fourteen or fifteen thousand years ago, around when the woolly rhinoceros went extinct. But recently, there have been several discoveries of much older human occupation sites,” said Love Dalén, author of the study and professor at the Centre for Palaeogenetics, a joint venture between Stockholm University and the Swedish Museum of Natural History.
According to the researchers, this indicates that the extinction of the species may not be related to the appearance of humans in the region.
They examined the DNA of tissue, bone, and hair samples from 14 of these megaherbivores. By analyzing genetic diversity, they were able to estimate population sizes for tens of thousands of years before the species’ extinction.
As a result, they found that the species remained stable and diverse until a few thousand years before they disappeared from Siberia, when temperatures soared, making adaptation unfeasible.
“We examined changes in population size and estimated inbreeding,” said co-author Nicolas Dussex, also a researcher at the Centre for Palaeogenetics in Sweden. “We found that after an increase in population size at the start of a cold period some 29,000 years ago, the woolly rhino population size remained constant and that at this time, inbreeding was low.”
This stability lasted well after humans began living in Siberia, in contrast to the declines that would be expected if overhunting were the cause of extinction.
“The data we looked at only goes up to 18,500 years ago, which is approximately 4,500 years before their extinction, so it implies that they declined sometime in that gap,” explained researcher and co-author Edana Lord.