Ancient Fallow Deer Lost Genetic Diversity After Ice Age

A new study reveals that modern fallow deer carry a fraction of the genetic diversity once found in their Ice Age ancestors.

An international team of researchers, including emeritus professor Wil Roebroeks of Leiden University's Faculty of Archaeology, has published a study in iScience showing that modern fallow deer have less genetic diversity than their Ice Age ancestors.

The Discovery

This single ancient population had genetic diversity comparable to all modern fallow deer across their current range—from Spain to Turkey.

The study analyzed ancient DNA from ten fallow deer specimens dating to around 125,000 years ago from the Neumark-Nord lake landscape in Germany. These remains represent a single, localized population that thrived during the Eemian interglacial period.

Why Diversity Was Lost

The findings suggest multiple genetically distinct fallow deer lineages once inhabited Europe. However, climatic changes during the Ice Age eliminated many populations, leaving only one lineage to survive in southern refuges. Humans later spread descendants of this lineage across Europe and beyond.

A Reclassification

Based on antler and anatomical differences, the Neumark-Nord deer had been classified as a separate species or subspecies. Genetic evidence now indicates they belong to the same species as modern fallow deer.

The research highlights how climate change and human activity have shaped the genetic history of animal populations over tens of thousands of years.

Publication Details

Title: "Eemian palaeogenetics demonstrates loss of diversity in modern fallow deer (Dama dama)"

Authors: Alberto Rocha-Méndez, Patrick Arnold, Lutz Kindler, Sabine Gaudzinski-Windheuser, Wil Roebroeks, Fulco Scherjon and Michael Hofreiter

Journal: iScience 29 (2026)