DNA Reveals Hippos Survived Europe’s Glacial Ice Age Against Expectations

Hippos Lived in Europe During Ice Age (Image: Canva)

Did hippos vanish from central Europe 115,000 years ago? New evidence indicates they lived much longer, lasting deep into the final Ice Age. A paper in Current Biology examined fossil remains in Germany's Upper Rhine Graben, illuminating these prehistoric giants and their surprising longevity.

How Did Scientists Rewrite Hippo History in Europe?

Scientists had long believed that central European hippos became extinct at the beginning of the Weichselian glaciation. The shift from warm interglacials to cold conditions about 115,000 years ago was supposed to render the area unlivable. Hippos require mild climates, abundant vegetation, and unfrozen water to survive, which made them indicators of warmer periods. Fossils found in sites like the Upper Rhine Graben were often automatically assigned to the earlier Eemian interglacial.

To investigate, the team analysed 19 hippo fossils and extracted a partial paleogenome from one specimen. Ancient DNA was compared against modern African hippo genomes to understand evolutionary links. Radiocarbon dating and amino acid geochronology then provided precise timelines for the fossils.

When Did Hippos Actually Live in Central Europe?

The findings were unexpected. Rather than vanishing 115,000 years ago, the bones suggested hippos existed in the center of Europe as recently as 31,000 years ago. This places them well into the Ice Age, still around long after previous estimates. Other Ice Age animals, such as woolly mammoths and rhinos from the same location, were dated to verify the results.

The research indicates that hippos lived through occasional warm intervals referred to as interstadials. These temporary phases provided local refuges with sufficient water and vegetation for the animals. The genetic analysis also indicated low genetic diversity, which depicted the population to be small and contained instead of spread out.

What Does This Mean for Understanding Ice Age Fauna?

The researchers propose that hippos did not persist continuously but recolonised during warmer phases. Animals may have moved in during favourable conditions and left as harsh glacial weather returned. The research also confirms the evolutionary connection between European Ice Age hippos and modern-day African common hippos.

The discovery rewrites the history of central Europe's Ice Age and provides new information on the survival of large mammals in climatic extremes. They emphasize the sophisticated survival methods of species under spectacular environmental changes.