The Denisova Cave might just be one of the most important spaces in human history (that researchers know of, at least). For thousands of years, this remote cavern in southern Siberia was frequented by humans, Neanderthals, and our now-extinct cousins the Denisovans. Here, these three hominins had sex, shared genes, birthed hybrids, and left a legacy that can still be seen in humans today.
That was the story, at least. However, as a new study has shown, the story of this cave is a lot more complex than the traditional narrative suggests.
Archeologists from Flinders University have taken a deep look at the layers of dirt and dust left in the cave network over the past 300,000 years using a technique called micromorphology to study archaeological deposits at microscopic scales. Reporting in the journal Scientific Reports, they found that the cave was actually inhabited by hyenas, wolves, and even bears for most of its history.
Humans and other hominins did certainly occupy the cave at times, but it looks like animals ruled this space for most of its history. This detailed survey of the cave floor found an unbelievable amount of fossilized animal poop but next to no indication of hominin activity, such as ash from fires.
It could be that the traces of hominins were washed away by water or weathered away by acidity. Alternatively, the most likely scenario is that ancient hominins probably came and went here for short-lived episodes and were regularly bullied out of the cave by large predators.
"Using microscopic analyses, our latest study shows sporadic hominin visits, illustrated by traces of the use of fire such as minuscule fragments, but with continuous use of the site by cave-dwelling carnivores such as hyenas and wolves," Professor Richard Roberts, from the University of Wollongong, said in a statement.
"Fossil droppings (coprolites) indicate the persistent presence of non-human cave dwellers, which are very unlikely to have cohabited with humans using the cave for shelter."
Until this year, the cave was the only place where archeologists had discovered the remains of Denisovans. Since the first discovery in 2010, scientists have continued to find tiny remnants, often no more than teeth and specks of bone, from four distinct Denisovan individuals in the cave. Then, in May 2019, scientists announced the discovery of a Denisovan jawbone in Tibet. The scarcity of direct evidence has hampered our understanding of Denisovans and researchers still know extremely little about this mysterious species.
Despite the absence of evidence, the Denisovans clearly left a mark on us. As a result of interbreeding, some gene variants derived from Denisovans are associated with certain modern human traits. For example, modern-day people from Tibet might be especially well adapated to high-altitudes partially thanks to Denisovan genes.