With the new DNA analysis methods available to researchers today, our understanding of how humans spread across the globe is becoming more and more complex. Not only have modern humans left Africa and discovered a world inhabited by Neanderthals and the mysterious Denisovan man, but it seems that there may have been other, previously unidentified species that influenced our development.
New DNA genome analysis
This finding is based on a recent analysis of the entire genome of DNA taken from people living in the Andaman Islands in Southeast Asia, as well as other Melanesians. Compared to them, in people living in India, whole pieces of DNA were found that do not correspond to any of the currently known human species. They are not characteristic of Neanderthals, Denisovans, or us. According to the researchers, this shows that the ancestors of people who now live in the Pacific Ocean may have been associated with hominids that are still unknown.
We can talk about a whole new species, since the history of human settlement in this region is complex. But also these unknown DNA fragments could be explained by another species called Homo Erectus, which, as we know, existed in southeast Asia, and, quite possibly, had contact with modern people. Unfortunately, there is no surviving fossil evidence of Homo erectus that would be sufficient for genetic analysis. So, while it may be Homo Erectus's DNA, there is currently no way to test it.
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"Escape" from Africa
As far as scientists know, the small group of modern humans that ultimately led to the birth of you and me left the African continent at least 60 thousand years ago. But they weren't the first human species to do this. Many ancient people - from Heidelberg man to Homo erectus - left Africa in the previous hundreds of thousands of years, even before we even began to exist as a species. They were scattered throughout Eurasia, resulting in the emergence of new species such as Neanderthals and "hobbits".
Relationships with other species
And when modern people finally appeared on the scene, they were rather late. Now we know that, having begun to colonize Europe, modern people interacted with Neanderthals who already lived there, and even had children in common. But the picture of these past events has become increasingly complex lately, as researchers have discovered that there may have been a third human species that interacted with our ancestors. Such conclusions were based on one bone fragment and two teeth found in a Siberian cave.
Scientists are now already acknowledging that these mysterious people, called Denisovans, also had close contacts with modern humans and Neanderthals, and their descendants spread throughout Southeast Asia. Modern geneticists say that people living in this area today have a higher proportion of Denisovan DNA than any other population in the world.
But now it seems too early to be satisfied with what has already been achieved, as new research shows that the picture of the region is more complex and confusing than anyone could have imagined. Since organic remains from this period could not have survived well enough due to the tropical climate, we will probably never know the true picture of our expansion from Africa.