Woolly mammoths(Mammuthus primigenius) were among the top prizes for humanIce Age hunters. The giant, 10,000-pound mammals provided meat, fat, hide, and bones for building structures, as well as ivory for tools, art, and ornaments. Our ancestors also may have specifically targeted female woolly mammoths, according to a study published today in the journalCurrent Biology.
DNA taken from over 500 mammoth bones show that the large mammoth bone deposits taken from places where humans were also active are mostly made up of female mammoth remains, compared to areas with less human activity.
“Whether these massive mammoth bone accumulations were formed naturally or by human hunting has been debated for decades,”David Díez del Molino, a study co-author and paleogeneticist at Stockholm University,said in a statement. “By comparing the genetic sex ratios of hundreds of mammoths from natural settings with those found in these archaeological contexts, we can now infer that human activity was the primary driver behind these bone accumulations.”
The team analyzed genome data extracted from roughly 30,000 to 20,000 year-old woolly mammoth bones. In total, they studied the remains of 521 woolly mammoths found across key Ice Age sites across present-day Europe, Asia, and North America.
Mammoth remains that were recovered from dispersed and natural settings were mostly male (66 percent). This is consistent with the idea that solitary (andaggressively hormonal) males were more likely to die in natural traps, such as landslides or sinkholes, increasing the chance that their bones would be preserved over thousands of years.
By comparison, bones found in sites where multiple mammoths were gathered together and near known human settlements were predominantly female (70 percent). These results raise some questions about how Ice Age hunter-gatherers interacted with wooly mammoths.
Projectilepoints embedded in mammoth bonesshow that Upper Palaeolithic (about 50,000 to 12,000 years ago) hunter-gatherers did sometimes directly hunt mammoths. The humans may also have scavenged material from carcasses.
“While it is tempting to assume that hunters would have targeted females because they were smaller than adult males, the reality may have been more complex,” added study co-authorJarosław Wilczyński, an archaeologist at the Polish Academy of Sciences. “If mammoths behaved like modern elephants, females living in matriarchal herds may have had group defences that would have made encounters with herds equally or even more risky.”
Another possibility is that the female-led herds moved across the land in more predictable patterns than solitary males.
“Upper Palaeolithic hunter-gatherers may simply have encountered them more frequently, whether for hunting or scavenging,” said co-authorHannah M. Moots, an archeologist postdoctoral researcher at Stockholm University.
Notably, the team identified one mammoth fromRussia’s Wrangel Islandthat was neither biologically female (withXX chromosomes) nor biologically male (withXY chromosomes). This mammoth had a different sex chromosome combination known asX0/XX mosaicisminstead. With X0/XX mosaicism, the organism has a single copy of the X chromosome in some cells, and two copies in others. X0/XX mosaicism is known asTurner syndromein humans and this is the first time it has been documented in an extinct species.
“This research demonstrates the power of ancient DNA studies to answer long-standing archaeological questions,” added co-authorLove Dalén, an evolutionary genomicist at Stockholm University. “By scaling up sample sizes, ancient DNA can go beyond evolutionary history to teach us about animal behaviour and human culture tens of thousands of years ago.”
Kaynak: Popular Science
