“These hominid groups and large carnivores such as hyenas and wolves left a wealth of microscopic traces that illuminate the use of (caves) over the last three glacial-interglacial cycles.”
Know them by what they left behind. In one of the less reported but fascinating anthropological finds about early humankind is that earth scientists are gaining new insights into the day-to-day lives of early human groups, including Neanderthals and Denisovans, thanks to analysis of dirt and dust found on the floors of a cave complex in Siberia.
As Arctic ice melts and glacial caps shrink, earth scientists are gaining access to secrets that previously lay buried under thick layers of prehistoric ice.
Researchers from Russia and Australia — yes, that Australia — are using modern geoarchaeological technology to examine tiny fragments of bone and fossilized animal droppings, as well as remnants of charcoal from the fires of early humans.
As reported late last summer in the journal Scientific Reports, the Denisova cave complex in Siberia’s Altai Mountains was frequented by hyenas, cave bears and wolves, alongside Neanderthals and, scientists now believe, early Homo sapiens.
These early would-be cave dwellers would not have made comfortable companions, nor would they have cohabited willingly.
The abundance of animal droppings suggests that large carnivores of the time — species that have long since gone extinct — were the apex predators of the labyrinthine cave systems all through Siberia and northern Europe, and presumably northern Canada as well. The theory that early humans, nomads for the most part, would have shared the caves with such predators is now considered unlikely. To a cave bear, or one of the early progenitors of the wolf or hyena, early humans would have been just another source of protein.
These new findings suggest that Neanderthals and early humans visited periodically but only stayed for brief periods of time.
Most studies depend almost exclusively on trace amounts of DNA to unravel the secrets of humankind’s origins, alongside visible artifacts, such as stone tools and animal or plant remains.
The latest findings suggest evidence can also be found by sifting through sediment that has remained undisturbed over not just centuries and millennia but entire epochs. Caves have traditionally shown themselves to be treasure troves for palaeoanthropologists and early earth scientists because the lack of direct light and outside air ensures that what’s left in the cave over time, stays in the cave.
Findings are subject to interpretation, of course, and some interpretations are bound to be controversial. DNA evidence suggests a previously unknown group of early hominids, Denisovans — named after the Siberian cave system — interbred with Neanderthals. Genomic analysis shows that between three and five percent of the DNA found in today’s Melanesians and Aboriginal Australians can be traced back to these very same cave complexes. The people of Papua New Guinea derive as much as six percent of their DNA from these same Denisovans.
There was never a single source population in the human past, the Harvard University geneticist David Reich wrote in Who We Are and How We Got Here. “The genome revolution has shown that we are not living in particularly special times when viewed from the perspective of the great sweep of the human past.”
Highly divergent groups have mixed and intermarried time and time again, “homogenizing populations as divergent from one another as Europeans, Africans and Native Americans.”
We are not unique, in other words, no matter how much some of us would like the rest of us to believe.