Credit Marc Händel/Austrian Academy of Sciences
An international team analysed ancient DNA from over 500 woolly mammoths. Published in Current Biology, the study shows Ice Age human sites are overwhelmingly female, resolving debates over whether bone accumulations stemmed from human hunting
For decades, archaeologists have debated whether massive Ice Age mammoth bone accumulations across Eurasia resulted from natural die-offs or human activity.
By analysing the genetic sex of 521 woolly mammoths across Eurasia and North America, including 448 newly sequenced individuals, a research team co-led by Stockholm University and the Polish Academy of Sciences has confirmed that human behaviour was the primary driver shaping these sites.
Divergent sex ratios expose human selection
The palaeogenomic data revealed a sharp contrast between natural fossil deposits and sites associated with Upper Palaeolithic human activity:
Natural sites (66% Male):
Dispersed mammoth remains preserved in natural traps (such as sinkholes, bogs, or landslides) were predominantly male. Scientists attribute this to young, solitary males taking greater behavioural risks and falling into natural hazards more frequently.
Archaeological sites (70% Female):
Bone accumulations spanning 11 key human-associated sites from 30,000 to 20,000 years ago were overwhelmingly female.
Hypotheses for the female preference
While female woolly mammoths were smaller than mature bulls, researchers note that targeting matriarchal herds carried its own challenges and opportunities:
Predictable herd movements:
If mammoths exhibited herd dynamics similar to modern elephants, female-led groups likely moved along predictable migratory routes, making them easier for Ice Age human hunter-gatherers to locate, track, hunt, or scavenge.
Resource optimisation:
Female herds provided critical resources—including meat, fat, hides, and bones for shelters—on a more reliable scale than sporadic encounters with solitary males.
A first-in-an-extinct-species genetic discovery
Beyond human interaction patterns, the large-scale genomic screening uncovered a rare genetic variation in a mammoth specimen from Wrangel Island.
The individual exhibited X0/XX mosaicism—a condition where some cells carry a single X chromosome while others carry two. Known as Turner syndrome in humans, this marks the first time the chromosomal condition has ever been documented in an extinct species.
The study demonstrates how scaling up ancient DNA sample sizes can answer deep archaeological questions, bridging the gap between animal behaviour, palaeoecology, and prehistoric human culture.
