In recent years, we have heard a lot about our extinct relatives - the Neanderthals, especially when it turned out that we also have their genes, writes the Danish scientific publication "Wiedenskab". And one cannot but ask the question: where did the Neanderthals come from, if they already lived in Europe, when our ancestors came there from Africa? Experts from Aarhus University answer this question.
In many ways, the history of the Neanderthals is our history. The story of how our roads parted begins from the moment about 700 thousand years ago, when a group of people went to explore new lands.
In recent years, we have heard a lot about our extinct relatives - the Neanderthals, and our view of their characteristics, one might say, has changed dramatically after it became clear that their genes are present today in our own genetic material.
This discovery suggests that we must be the descendants of children who arose from the connection of modern humans with Neanderthals at a time when our ancestors left Africa and began to populate territories in Europe and the Middle East.
But all this talk about Neanderthals has caused confusion for our attentive reader Jørn Nielsen, who wondered:
“When our ancestors came from Africa to Europe, the Neanderthals were already there. And where did they come from then?"
We began to look for the answer to this question with the help of two enthusiastic scientists from Aarhus University: Professor Felix Riede from the Department of Archeology and Cultural Heritage, and also Professor Mikkel Heide Schierup from the Center for Bioinformatics.
“This fall I was at a conference dedicated to just how well we figured out human evolution. It was a very interesting conference because some of the best archaeologists and geneticists like me were invited to it,”says Mikkel Heide Schirup.
Promotional video:
Natives of Africa adapted to the conditions of the ice age
To start from the very beginning, I must say that scientists have been very interested in Neanderthals since the middle of the 19th century, when it became known about their existence.
The first bones and skulls were found in Germany, Gibraltar and Belgium, and the numerous finds that followed showed that the Neanderthals spread over a vast area from the Atlantic coast of Europe in the west to Siberia in the east and present-day Israel in the south.
Neanderthals are not the most ancient human species found in Europe. For example, found in the famous Spanish burial - the Cave of Bones - the remains may belong to the possible ancestors of the Neanderthals.
If you take a closer look at the fossils found in Europe, you can see from the skeletons how the appearance of people has evolved to the "typically Neanderthal", which could be found already about 150-200 thousand years ago.
Heidelberg Man is considered our common ancestor
Many scientists believe that the Heidelberg man (Homo heidelbergensis) is the ancestor of both Neanderthals and modern humans.
“In Italian Ceprano and Greek Petralona were found the most important fossils, which were identified as the remains of early and late Heidelberg man, respectively. One of the finds from the Petralona Cave shows clear traces of the transition to Neanderthal at that time,”says Felix Riede.
Compared to the ancestors of modern people, the Neanderthals belonged to the branch, whose representatives left Africa early and adapted to the conditions of the ice age, which then reigned in Europe.
Today, geneticists can give a fairly accurate answer to the question of exactly when this happened, but first let's go back a step and briefly outline the history of the African family.
We are the descendants of Homo erectus
Our entire genus "homo" (lat. "Man") from the hominid family comes from Africa, where our ancestors shared with chimpanzees lived six to seven million years ago.
The first in our branch of development were bipedal primates (Australopithecus) like the famous "Lucy" (Afar Australopithecus).
But the first person (that is, a representative of the genus "Homo"), very similar to us, with a tall, slender body and a large brain, was "Homo erectus", who lived about two million years ago.
It is from the moment of the appearance of Homo erectus that our race seriously enters the scene, and also takes the first step away from Africa.
“If you look at the big picture, then both we and the Neanderthals are descendants of Homo erectus,” says Felix Riede.
Simply put, Homo erectus is the root from which Heidelberg man grew, and from which we and the Neanderthals spun off, and with the help of new genetic methods, scientists can figure out exactly when this happened.
The lines of modern humans and Neanderthals split 700,000 years ago.
After they managed to extract fossil DNA from the bones of Neanderthals and obtain complete genetic information about several individuals, the researchers were able to calculate when the lines of modern humans and Neanderthals diverged from the closest common ancestor.
In short, scientists do this by comparing our genetic material with the genetic material of Neanderthals and counting the number of differences.
It is known that mutations occur in DNA regularly, and when two populations live in isolation from each other, without exchanging DNA, then in each of the groups a unique set of mutations will accumulate over time.
Therefore, by counting the number of different mutations, scientists can determine how much time has passed since the two branches began to develop separately from each other.
“It turned out that the lineages of Neanderthals and modern humans split about 700,000 years ago,” says Professor Mikkel Schirup.
After that, each of the lineages developed on its own, with the result that one of the groups turned into Neanderthals, and the other into modern humans.
"We assume that the ancestors of the Neanderthals came from Africa, but in fact it could well be that their group split off somewhere else in Africa and only then they left for Europe."
In other words, DNA cannot determine exactly where the split occurred geographically, so it is possible that people split into two groups back in Africa and lived for some time in different places before the ancestors of the Neanderthals migrated.
The ancestors of the Neanderthals came to Europe 400-500 thousand years ago
Climatic data indicate that in the last couple of million years on the planet, long ice ages alternated with short interglacial intervals.
During the ice ages, the territories that could be traversed from Africa to Europe were dry and barren, while during the interglacial they were moist and rich in vegetation.
Therefore, scientists assume that the ancestors of the Neanderthals in one of the interglacial periods left Africa after the herds of large mammals, and the new ice age, figuratively speaking, slammed the door behind them.
Fossil finds in Europe, for example, in the Cave of Bones, and DNA extracted from them indicate that the ancestors of the Neanderthals probably came to Europe no later than 400-500 thousand years ago.
Neanderthal ancestors split up
Fossil DNA also revealed unexpected new pages in Neanderthal history.
For example, scientists recently discovered that the Neanderthals had a sister group of people called Denisovans. This is a species of people, described only by the genetic material of the bone of the phalanx of the finger and two teeth, excavated in a cave in Siberia, so we know that they existed, but we do not know what they looked like.
Scientists have quantified the genetic differences between Neanderthals and Denisovans in the same way they did, studying the differences between Neanderthals and us. It turned out that these two types of man split 400-500 thousand years ago.
In addition, scientists have discovered an even more interesting fact, which is that modern people living in Southeast Asia (but not in Europe) carry Denisovan genes, which they inherited as a result of prehistoric intimate interspecies encounters.
“It looks like the Neanderthals lived more in the west, and the Denisovans in the east, and they only exchanged a small piece of DNA,” says Mikkel Schirup.
Neanderthals are descendants of prehistoric adventurers
To summarize, we can say that Neanderthals appear to be the descendants of inquisitive pioneer explorers who set out from Africa following herds of animals about 700 thousand years ago.
Curious hunters discovered completely new lands that stretched for thousands of kilometers to the east and west, and the Neanderthals descended from the group that went west 400-500 thousand years ago, and the Denisovans from those who went east to Asia.
We modern people are the descendants of those people who initially stayed at home in Africa. There are examples that in the interglacial period children were born to mixed pairs of people from Europe and Africa, but only 60-70 thousand years ago modern people began to settle and in a short time occupied the entire globe, during this great wave of migration, having children as with Neanderthals, and together with Denisovans.
Neanderthals continue to live in us
That is why the Neanderthals disappeared, however, according to DNA information, we can say that they still exist as part of any of us.
You could even say that their DNA on Earth is now greater than ever before in history.
Rasmus Kragh Jakobsen