Denisovans are an extinct species of hominid and a close relative to modern humans. They’re a recent addition to the human family tree—scientists first identified Denisovan remains from a cave in Siberia in 2010. Denisovans may have ranged from Siberia to Southeast Asia during the last Ice Age. DNA evidence suggests Denisovans are related to both Neanderthals and modern humans, and may have interbred with both.
Denisovans share a common ancestor with both modern humans and Neanderthals. This common ancestor, called Homo heidelbergensis, most likely lived in Africa.
Between 300,000 and 400,000 years ago, one group of Homo heidelbergensis left Africa. They expanded into Eurasia and then split: Those that moved west into Europe evolved into Neanderthals. The ones that moved east into Asia became Denisovans.
The human ancestors that remained in Africa evolved into our own species—Homo sapiens. Modern humans and Denisovans likely met for the first time in Eurasia some 40,000 to 60,000 years ago, after Homo sapiens began their own migration out of Africa.
Denisovan Discovery
Denisovans are a relatively recent discovery: In 2008, Russian paleoanthropologists exploring Siberia’s Denisova Cave—located in the Altai Mountains along Russia’s southern border with China and Mongolia—found a tiny, pea-sized fragment of finger bone.
They determined the fossilized pinkie bone had belonged to a young girl between the ages of about five and seven when she died roughly 40,000 years ago. Cold weather in the Siberian cave helped to preserve ancient DNA.
In 2010, a group of scientists led by Svante Paabo of the Max Planck Society in Germany extracted DNA from the tiny bone fragment.
Scientists sequenced the girl’s genome and compared it to the genomes of modern humans and Neanderthals—two other hominin species known to be living in Eurasia at the time. Studies showed that the girl was genetically similar to both Neanderthals and Homo sapiens, but distinct enough to be considered a new species of human.
The researchers named the archaic humans Denisovans after the cave in Siberia where the fossil was discovered. Scientists have since discovered fossilized teeth from three other Denisovan individuals—all from inside Denisova Cave.
Denisovan DNA
Since very few Denisovan fossils have been found, most of what we know about the extinct humans comes from their DNA.
It’s not clear when exactly Denisovans evolved—or when they went extinct—but DNA evidence suggests they were living in Asia at least 80,000 years ago. They may have had dark skin, dark hair and dark eyes. The Denisovan genome appears to have low genetic diversity, which means their population may never have been very large.
Researchers believe that modern human ancestors may have interbred with Denisovans. Denisovan DNA can be found in the human genome.
Melanesians
Some present-day East Asian groups, in particular Melanesians, may have inherited up to five percent of their genetic material from Denisovans. Melanesians are Pacific Islanders native to a region spanning from Papua New Guinea to Fiji.
Scientists theorize that Denisovans living in East Asia may have interbred with the ancestors of present day Melanesians before those humans crossed the Pacific Ocean to reach Papua New Guinea approximately 45,000 years ago.
Tibetans and Han Chinese have traces of Denisovan DNA in their genomes too. In 2014, researchers discovered that ethnic Sherpas likely inherited from Denisovans a “super athlete” gene variant that helps them breathe easily at high altitudes.
Sources
Why Am I Denisovan?, National Geographic.
Genetic history of archaic hominin group from Denisova Cave in Siberia, Nature.
Tibetans inherited high-altitude gene from ancient human, Science Magazine.
