Peking University, Sep 28, 2026: The woolly rhinoceros was one of the most iconic cold-adapted animals of the Pleistocene. Yet its genetic origins, population history, and responses to repeated glacial–interglacial cycles have remained poorly understood.
Figure 1. Artistic reconstruction of woolly rhinoceroses and their habitat in mid-latitude regions during the Late Pleistocene.
A research team led by Yu He from the School of Life Sciences, together with collaborators from the Chinese Academy of Sciences and other institutions, has reconstructed the evolutionary history and habitat dynamics of woolly rhinoceroses over the past 500,000 years. The study was published in Science on September 10, 2026.
Why it matters Ancient-DNA research often focuses on high-latitude regions, where cold and dry conditions favor DNA preservation. This study shows that woolly rhinoceros genetic diversity was formed and maintained mainly in temperate, mid-latitude Eurasia. These regions may have served as long-term centers of genetic diversity rather than merely temporary refuges during severe climatic periods.
Key findings The researchers analyzed 29 mitochondrial genomes and 14 nuclear genomes from woolly rhinoceros remains collected at 10 sites or regions across Eurasia. The samples date from approximately 230,000 to 18,000 years ago and include previously under-sampled mid-latitude regions. The team also modeled habitability from 500,000 years ago until the species became extinct.
The analysis estimated that the most recent common ancestor of woolly rhinoceroses lived about 460,000 years ago, close to the earliest known fossil records and during Marine Isotopic Stage 12 (MIS 12), a major glacial period. The major mitochondrial lineages diverged between about 460,000 and 420,000 years ago, around the transition from MIS 12 to the warmer MIS 11.
Habitat models indicate that suitable habitat contracted and became fragmented across Eurasia during this transition, potentially driving genetic separation among populations. During the Last Interglacial, suitable areas were largely restricted to central Eurasia, the Russian Far East, and neighboring regions. These isolated refugia may have contributed to regional genetic differentiation.
The Altai region remained hospitable for at least 160,000 years, spanning multiple glacial–interglacial cycles. In Eastern Europe, habitat suitability did not recover until about 70,000 years ago, which may help explain the region’s lower nuclear-genome diversity. Genetic analyses identified distinct lineages in East Asia, the Altai, and Europe, while northeastern Siberian populations appear to have formed through admixture between Altai and East Asian populations.
Figure 2. Woolly rhinoceros skull fossil. Specimen held at the National Natural History Museum of China.
Figure 3. Spatiotemporal distribution of the ancient woolly rhinoceros genomes analyzed in this study (A) and changes in habitat suitability over the past 500,000 years (B–G) Future implications The study highlights the importance of temperate Eurasia in the evolution of cold-adapted species and demonstrates the potential of paleogenomic research in mid- and low-latitude regions. Expanded sampling and higher-resolution environmental modeling may reveal further details about woolly rhinoceros evolution and the history of other Ice Age megafauna.
*This article is featured in PKU News "Why It Matters" series. More from this series. Read more: https://www.science.org/doi/10.1126/science.aed0430
Written by: Akaash Babar Edited by: Chen Shizhuo Source: PKU News (Chinese)
