Ancient DNA reveals Ice Age humans targeted female woolly mammoths

Ancient DNA analysis has revealed that Ice Age humans deliberately targeted female woolly mammoths, according to a new study published in Current Biology. Researchers examined over 500 mammoth bones and determined that human activity significantly influenced the distribution of mammoth remains, particularly favoring females. The findings challenge previous assumptions about how early humans interacted with these prehistoric giants. The study compared the sex ratios of mammoth remains found in two distinct environments: natural settings and locations linked to human activity. In natural areas, such as sinkholes or landslide zones, the majority of remains were male, comprising 66% of the total. This aligns with the theory that solitary male mammoths were more prone to falling into such hazards, leading to their greater representation in the fossil record. However, in regions where human presence was evident, such as archaeological sites, the proportion of female remains rose sharply to 70%, while male remains dropped to 30%. This discrepancy suggests that humans actively sought out female mammoths, possibly due to specific behavioral patterns or resource availability. Researchers used genetic data from 521 woolly mammoths spanning Eurasia and North America, with 448 of these individuals being sequenced for the first time. The genetic analysis allowed scientists to determine the sex of each specimen accurately. The study's lead author, Hannah M. Moots, noted that while it might seem logical to target smaller females, the dynamics could be more intricate. She suggested that female-led herds may have traveled along more predictable routes, making them easier targets for hunter-gatherers. Alternatively, the social structure of female-dominated groups might have posed unique challenges or opportunities for interaction. The implications of this research extend beyond understanding mammoth behavior. Woolly mammoths were crucial to Ice Age human societies, offering resources such as meat, fat, hides, and bones used for construction, as well as ivory for tools, art, and adornments. The study focused on 11 major Ice Age archaeological sites across Eurasia, with remains dated between approximately 30,000 and 20,000 years ago. By integrating data from 100 mammoths found in human-associated sites with 421 from natural settings, the researchers created a comprehensive dataset that offers insights into the interactions between humans and mammoths during the Late Pleistocene. Love Dalén, a professor of evolutionary genomics at Stockholm University and co-senior author of the study, emphasized the significance of using ancient DNA to address longstanding archaeological questions. He highlighted how expanding sample sizes allows ancient DNA research to move beyond evolutionary history and provide information about animal behavior and human cultural practices from tens of thousands of years ago. One notable finding from the study was the identification of a mammoth from Wrangel Island whose genetic makeup did not conform to typical XX or XY chromosomes. This unusual case adds another layer of complexity to the understanding of mammoth biology and evolution. While the exact nature of this genetic anomaly remains under investigation, it underscores the potential for further discoveries through continued analysis of ancient genomes. David Díez del Molino, a researcher at the Centre for Palaeogenetics and co-senior author of the study, pointed out that the debate over whether mammoth bone accumulations resulted from natural processes or human activity has persisted for decades. By comparing the genetic sex ratios of mammoths from both natural and human-influenced contexts, the team concluded that human activity was the main factor driving the formation of these accumulations. This conclusion reshapes current perspectives on how early humans engaged with and utilized mammoth resources. The study’s findings contribute to a growing body of evidence suggesting that human impact on megafauna was substantial during the Ice Age. As researchers continue to analyze ancient DNA, they hope to uncover more details about the relationships between early humans and the large animals that once roamed the Earth.