Feb 18, 2026
The pace of new knowledge about our distant ancestors and their relatives has been astonishing in the last 20 years or so. Probably the biggest new discovery has been the Denisovans. We first knew of them in 2010 from DNA analysis of remains found in Denisova Cave, Siberia. The state of the art of DNA sequencing had advanced to the point where even ancient remains could be analysed - this is in large part the work of Svante Pääbo's group at Max Planck Institute in Leipzig. He won the 2022 Nobel Prize for this and other work sequencing the genomes of Neanderthals and other ancient humans.
It was clear from the DNA that Denisovans were related to us, and to Neanderthals, but distinct from both, with a common ancestor something like a million years ago.
Also in 2010, analysis of the Neanderthal genome by a large group of collaborators, including Pääbo and others at Max Planck - but other people too, I don't want this to just be a Svante Pääbo hagiography - showed that modern humans outside Africa all have a small fraction, several percent, of Neanderthal ancestry. Not long after it was discovered that Asians and Australasians, but not Europeans, also have varying levels of Denisovan ancestry. This opened up a hugely active field of research, and new papers are coming out all the time studying the varying degrees of Neanderthal and Denisovan ancestry in various places, and making inferences about where such populations may have lived.
The fact of us all having ancestry from outside our own species was a surprise to many. There were of course those who just didn't like to imagine the necessary goings-on implied by the finding. More reasonably, we tend to assume our own species to be superior, as evidenced by us still being here while other human and related species aren't, so the question is if interbreeding did occur why did some of their genome persist, rather than being diluted to nothing by the homo sapiens genome, especially given the likelihood of fertility problems across such a genetic distance? The first part of the answer is that we probably aren't quite as superior as we like to imagine. The second part is that we know homo sapiens was mostly confined to Africa until something like 60kya (60 thousand years ago), whereas Neanderthals and Denisovans lived elsewhere much earlier than that. Our remote relatives had many tens of thousands of years of adaptation to non-African environments which our own species didn't have. By obtaining some of these genetic adaptations from those we met on the way we could get a head start on the process of adaptation. Hybrid humans with the right sort of DNA inherited from a Neanderthal or Denisovan may have had a survival advantage over those without such an inheritance. We have a reasonable idea of how this worked in some places. People who live at high altitudes in the Himalayas gain benefit from Denisovan high altitude adaptation. Melanesians get some malaria resistance from a Denisovan genetic adaptation. The side effect of increased risk of anemia is worth it if you live where malaria is common. This of course implies that malaria was common before homo sapiens were present - ie that the disease itself first evolved to attack our distant relatives.
The other surprising thing of course is that modern humans, Neanderthals and Denisovans could interbreed at all. If you did biology at high school you probably learned that the definition of a species is where individuals of that species can produce fertile offspring. So by this strict definition, we are all the same species. This is an active area of debate, between those who argue we are indeed all homo sapiens, and those who prefer a more liberal definition of a species. The fundamental fact remains that nature will do its own thing without caring what labels we apply.
There has been a longstanding issue with some Chinese fossil finds that don't quite seem to be homo sapiens, and also aren't quite Homo Erectus or older hominins. Some Chinese scholars suggested this may be evidence that homo sapiens, or at least a Chinese subset thereof, actually evolved in China, whereas most foreigners just had it classified with a big question mark pending future revelations. The future revelations finally occurred - a skull found in a well in Harbin many years ago recently came to light, and was given the name homo longi (a Latin-Chinese language mashup meaning "dragon man"). When genetic analysis was performed it was shown to be a Denisovan. A jawbone found in the sea near Taiwan was also found to be Denisovan. In that case the DNA was too badly decayed to be analysed directly, but since a primary function of DNA is to manufacture specific proteins, if we can identify proteins precisely enough we can infer the DNA, and that is what was done here. There are many such hominin remains in China that have yet to be analysed - it seems a fair assumption that a significant proportion of them will turn out to be Denisovan. Since the homo longi finding proceeded as far as choosing a proper taxonomic name for the specimen, that may well become the name for Denisovans in general, which I think would be a good step forward as Denisovan is a little awkward to pronounce.
What we can infer from the DNA evidence and the paleontological finds is that there were several Denisovan populations in various parts of Asia. Modern Papuans and Australian Aborigines have a particularly high level of Denisovan ancestry, so it seems there must have been a large Denisovan population somewhere in the regions their ancestors must have passed through on their way, probably Eastern Indonesia. In addition to Eastern Indonesia, it's likely there were populations all over Asia, including Tibet, Siberia, Laos and China. Significantly their domain covered a huge variety of different types of environment. They were clearly good at adapting, or at the very least they were there long enough to become good at adapting.
There is a lot we don't know about Denisovans - exactly where and how they lived, what their material culture was like, what technologies did they use, what sort of language did they have, what happened when modern humans met them, why did we apparently mostly replace them. We have similar questions about Neanderthals, but we know a little more about them due to their domain in Europe being more thoroughly studied by paleontologists over the years. Asian paleontology seems to be growing, at least in part as a side effect of the economic development of Asian countries, so we can hope to learn much more in coming years.