Although most of us don’t really think about this often, we are members of the animal kingdom. And like all animals, we are members of a family of animals: in our case, the primates, or apes. And on our family tree, there are other living cousins, like the chimpanzee and gorilla. We all evolved form common ancestors, and Home sapiens, our species, evolved from earlier ancestor species.

But during our evolutionary journey, our family tree had some branches – other ape-men who became extinct. You may have heard of the Neanderthal. Perhaps also you know about the “hobbits”, our miniature cousins whose remains were found in Indonesia.

But you probably have not heard about the Denisovans, because they are a very recent discovery – it was only in 2008 that scientists were shocked when they identified a bone found in a Russian cave as the remains of a new and previously unknown species.

What scientists have learned about the Denisovans has made people start to believe that they could be the origin of Asian legends about giants and the yeti of the Himalayas. And it also appears that the Denisovans could be the key to understanding why Asian peoples are different from Europeans.

AN AMAZING DISCOVERY

The name Denisovan comes from the Denisova Cave, which is in the remote Altai mountains on the borders of Russia, China and Mongolia. Scientists were searching the cave for tools made by ancient humans when they found a single finger bone fossil that was 40,000 years old. At first, they assumed it was from a Neanderthal, as it looked so similar. But when they performed a DNA analysis, they were amazed to see that the results showed the bone is from a completely new species that had never been known before.

The DNA in the bone had a lot in common with our own human DNA, but more in common with the extinct Neanderthal, our relative. However, the bone also had some unique DNA that meant it was not Neanderthal either. That is how scientists knew they had found a new species. And when they checked back on fossils found in the cave in previous years, they also found that some teeth they had found in the year 2000 were also Denisovan.

Scientists can also use DNA analysis to get an approximate ate when different species evolved, and when they did this, they found that human (Home sapiens) and the Neanderthals came from a common ancestor over a million years ago. Then about 400,000 years ago, the Denisovans evolved from their Neanderthal cousins.

ALL ASIANS SEEM TO HAVE DENISOVAN GENES

The next thing the scientists did was to look at modern human DNA to see if there were any traces of Denisovan DNA. And that is what they found. There are Denisovan genes in modern human genes. This was proof that Denisovans must have bred and had children with our own Home sapiens ancestors.

The traces of Denisovan genes are in modern Asian genes – in fact, across Asia, most people have some genes from Denisovans (in the same way that most European have some Neanderthal genes).

The people with the greatest proportion of Denisovan genes are in south-east Asia: so the native races of Papua New Guinea and Australia have about 5% Denisovan genes; in the Philippines the figure is 6%; and across Asia as a whole, most people have 1-2% Denisovan genes. But the only people outside Asia with any Denisovan genes is a small group of people in modern Spain, who are different to other Europeans.

So the conclusion many have come to is that Denisovan genes are what make Asian people different from European or African people.

The discovery of the Denisovans has also answered a medical mystery. Tibetan people have a unique genetic mutation that allows them to live at very high altitudes and the very low blood oxygen levels that means. Scientists could not explain this mutation until they compared Tibetan genes to Denisovan genes – and found a match. The gene that lets Tibetans live so high up comes from their Denisovan heritage. Only the Tibetan people have this unique genetic mutation, so their ancestors must have bred with Denisovans, and comparatively recently.

Now that scientists know that Denisovans exist, they are going back to fossils in museums and universities that were previously labelled as Neanderthal. And they are finding that some are indeed actually Denisovan. It will take decades to check all the fossils, so there could be a lot more Denisovan fossils to find.

STORIES OF GIANTS – INSPIRED BY THE DENISOVANS?

All Over Asia, there are legends of giants, who were different to normal men: not just very tall men, but much more powerfully built and usually much hairier. And the stories often said the giants lived in mountains and in caves.

And of course there are stories of the yeti, the giant hairy creature who lives in the Himalayas around Tibet.

Were these stories inspired by the Denisovans? When experts have examined the facts, they are now concluding that there is a link to the stories.

So far only a finger bone of a Denisovans has been found, plus some teeth. This is not enough to say what Denisovans looked like, but because we know from DNA that Denisovans are closely related to Neanderthals, we can use them as a model, because we know what Neanderthals looked like.

<have picture here of a Neanderthal with caption “A Neanderthal”>

Compared to our own ancestors, Neanderthals were taller and much more powerfully built. They were better hunters, much stronger and faster, and they were also much hairier too. Neanderthals died out 28,000 years ago, recently enough that it is possible for inherited legends to remember them (in the Middle East there are stories about events nearly 10,000 years ago, so this is not as strange as it sounds).

We also know that Neanderthals have been found living in colder climates than our own ancestors – near the edge of Ice Age glaciers, in northern forests and in mountains. Many of their remains have been found in caves where they lived.

It has long been thought that stories about Neanderthals told in Europe could have led to the European legends of hairy mountain men – giants and ogres.

And if that is true in Europe, could the Asian cousins of Neanderthals, the Denisovans, have led to the Asian stories about giants. Except for living in Asia, it is very likely they lived the same way and looked very similar to the Neanderthals.

DENISOVANS AND THE YETI

There are important links between the Denisovans and the high mountains of Asia. The Denisovan bone was found in a cave in the Siberian Altai mountain range. There are even stories in the location about giants living in the caves.

And there are close links between the Denisovans and Tibet, as we said earlier. The Altai mountains are only a few hundred kilometres north of Tibet – indeed the Altai mountains are often called “the Russian Tibet.” The stories of giants in the Tibetan mountains are thousands of years old, and perhaps the Himalayan Yeti was inspired by memories of the large and hairy Denisovans.

But sightings of the Yeti still happen in the present day. It’s astonishing to think that could mean there are some Denisovans still alive today, hiding in the world’s highest mountains. The Denisovans would be much better suited to life here than most humans – like their Neanderthal cousins, their stocky build and hairiness would keep them warmer. And we know from the DNA tests that Denisovans have that special gene that allows the Tibetans to live at such high altitudes without getting altitude sickness.

Lastly, we know from the DNA evidence that Denisovans must have interbred with the Tibetans. Scientists who have studied the special altitude gene say that the Tibetan people only split from their Chinese Han cousins within the past 10,000 years, and the Han don’t have the altitude gene, so the interbreeding between Denisovans and Tibetans must have happened less than 10,000 years ago.

We know from other parts of the world that stories have survived with memories of events that long ago, so there is no reason why stories of the Denisovans should not have survived. Perhaps as more Denisovan remains are found, the riddles will be solved, and our questions will be answered. We cannot be certain at present, but as you have read here, there are many reasons to think our Denisovan cousins are remembered in our legends of Asian giants.