National Geographic has a great article on the discovery and further research related to our cousins the Denisovans. Everyone knows about the Neandarthals, and at this point I think most people know that large portions humans living today have some percentage of Neanderthal DNA. I was completely in the dark about the prospect of another subspecies of Homo sapiens which moved out of Africa and is carried in the DNA of some modern humans – The Denisovans:
A third kind of human, called Denisovans, seems to have coexisted in Asia with Neanderthals and early modern humans… Although the Denisovans’ genome showed that they were more closely related to the Neanderthals, they too had left their mark on us. But the geographic pattern of that legacy was odd. When the researchers compared the Denisovan genome with those of various modern human populations, they found no trace of it in Russia or nearby China, or anywhere else, for that matter—except in the genomes of New Guineans, other people from islands in Melanesia, and Australian Aborigines. On average their genomes are about 5 percent Denisovan. Negritos in the Philippines have as much as 2.5 percent.
What is amazing about this discovery is that it was all discovered from two teeth and part of a finger bone. Three separate individuals who died in a remote cave in the Altai Mountains in Siberia, a cave which has also been inhabited by Neanderthals and modern humans. Thus far the Denisovians have been found no where else, however, as the article points out the southern climates mean DNA is unlikely to survive. In fact the cool temperature in a Siberian cave is likely the only reason they were able to pull significant DNA out of the finger bone. Genetics and the ability to pull DNA from very old remains is such an incredible change to the way our history is studied – we no longer have to guess at what fragments mean, we can read the history directly from their essence.