Europeans can trace their roots by analyzing clues from the distant past found in their DNA. The researchers, who traced the history of Europeans by combining archaeological findings with genetic data
Tamara Traubman
Europeans can trace their roots by analyzing clues from the distant past found in their DNA. The researchers, who traced the history of Europeans by combining archaeological findings with genetic data, believe that in this way they will be able to reconstruct all of human history
Our ancestors developed in Africa, and more than 100 thousand years ago they went on a journey and dispersed all over the world. Time will blur their migration routes, but in the chain of DNA units, folded in each of our body cells, there remain clues to lost human history, the migration routes and the ancient origins of the peoples. Scientists believe they are now on the verge of reconstructing human history, from the first modern man born in Africa to the beginning of written history, around 3,500 BC.
This history consists of a synthesis of archaeological findings and genetic data. The first chapter drawn up traces the history of the Europeans, and it was published this month in the scientific journal "Science." In a telephone interview from his office at Stanford University in the USA, the head of the research team, Prof. Peter Underhill, said that another study of theirs, which traced the population of the other continents, will be published in the spring in writing The scientific journal "Annals" "of Human Genetics".
"It's amazing how much archeology is starting to learn from genetics," said Prof. Colin Renfrew, a prominent archaeologist from the University of Cambridge in England, in a telephone interview. In a study published in November - one of the most detailed reconstructions published so far on the family tree of the European population - Dr. Martin Richards from the University of Huddersfield in England, Prof. Ariela Oppenheim from the School of Medicine of the Hebrew University of Hadassah and others discovered the ancient origins of the inhabitants of Europe today.
According to Dr. Richards' calculations, approximately 6% of Europeans are descendants of humans who came to the continent from the Middle East in the Upper Paleolithic period, approximately 45 thousand years ago. The descendants of these early settlers are still more numerous in certain areas of Europe, which may have served as a refuge from the waves of immigration that followed them. One of these havens is the mountainous Basque Country.
The Basques have a certain genetic mark that distinguishes them from almost all other Europeans, and they still speak a very different language from the rest of European languages. "The Basque language is probably the last remnant of the ancient European settlers, before the pre-Indo-European languages arrived on the continent," says Prof. Renfrew, who is also an expert in Indo-European languages.
Dr. Richards' research is based on analyzing data from the mitochondrial DNA, which is inherited only from the mother to her sons and daughters, therefore it reflects the migration patterns of women. To study male migration patterns, Prof. Underhill studied genetic markers on the Y chromosome, the chromosome that determines male sex. This chromosome is passed in its entirety from father to son, but from time to time mutations occur in it during its replication. By comparing the frequency of certain mutations among different ethnic groups, geneticists can estimate the degree of kinship between groups and build their family tree. They can also calculate the average rate of the occurrence of mutations, estimate how long ago a mutation appeared and also try to determine when one group split from another and reconstruct the trajectory of its movement.
The data extracted from the mitochondrial DNA is largely consistent with the data from the Y chromosome, but there are some differences: for example, Prof. Underhill and his colleagues were unable to find in their Y chromosome data a parallel migration to the migration that occurred 45 thousand years ago. He says that this may be due to the fact that some of the male Y lineages have become extinct and today no trace of them can be found.
A comparison between the two studies also shows that the degree of variation between the Y chromosomes of the European men is much smaller than the degree of variation seen in the mitochondrial DNA. This pattern was also repeated in a study led by Prof. Batsheva Bona-Tamir from Tel Aviv University, which examined Middle Eastern populations. Ornella Semino, another partner in the study, said in an interview from her office at the University of Pavia in Italy, that there are several possible explanations for this: polygamy (one man fertilized many women; therefore only one Y chromosome was passed on, but a lot of different mitochondrial DNA); More men died because they were engaged in more dangerous activities such as hunting; And also because usually the women are the ones who moved their place of residence following their marriage. It is possible that some European ancestors have no representation on the Y chromosome because they only had daughters.
The Paleolithic inhabitants made a living by hunting and gathering food, which is why archaeologists call them "hunter-gatherers". But about 7,000 years ago, during the Neolithic period, the inhabitants of Europe experienced a dramatic change in their way of life. In sites from this period onwards, archaeologists have discovered remains of wheat, barley, sheep and goats - these can only be the result of agriculture and the domestication of grazing animals.
The change had far-reaching consequences for the social and family structure of humanity. It allowed humans to live in larger groups, establish permanent settlements, villages and eventually cities. It was a revolution, says Prof. Anna Belfer-Cohen, a pre-historian from the Hebrew University.
But who were the people who caused the revolution and what mark did they leave on the Europeans of our time? It was commonly thought that the Neolithic farmers who came to Europe with their relatively advanced technology displaced the older Paleolithic ones and replaced them. Now, for the first time, after many years of debate, it is possible to answer these questions not only through ancient remains but also through the DNA of living Europeans. The genetic data suggest that the ancient hunter-gatherers, who lived in the Paleolithic period, are the ones who survived and were the main ancestors of Europeans. More than 80% of European men inherited their Y chromosomes from Paleolithic ancestors who lived 40-25 thousand years ago. Only about 20% of Europeans are descendants of Neolithic farmers. Therefore, the genetic pattern of men in Europe was already determined 40 years ago, and then changed - but not reshaped - by the Neolithic farmers, who, according to the study, probably migrated to Europe about 9,000 years ago.
In a bold step, which has already drawn criticism, Prof. Underhill and his colleagues linked genetic data to archaeological findings from ancient cultures. They linked two early migrations, hints of which appear on the Y chromosome, to two Paleolithic cultures: the Aurinaician culture and the Gravtian culture, both famous for the spectacular art they produced.
Underhill's calculations imply that humans carrying a genetic mutation designated M173 came to Europe from Eurasia 35 to 40 years ago. He points out that this is exactly the time of the appearance of the Aurignacian culture, a culture that reached its peak in Western Europe about 35 years ago and is well known for its wall paintings and tools and figurines made of horn, bone and ivory. If Underhill is right, about half of Europeans still carry the genetic imprint of these ancient artists. "There is no doubt that certain places in Eastern Europe also have strong Aurignacian signs, and this is also present in the archaeological record," he says. Underhill, whose family comes from Poland, says that he tested his own Y chromosome and discovered that he too carries the Urinike seal. The M173 mutation also exists today in American Indians, and according to Underhill, some of these people may have later migrated from Siberia to America.
A second migration wave, indicated by mutation M170, probably arrived in Europe 22 thousand years ago from the Middle East. The researchers linked the wave to the Gravtian culture, known for cave paintings, figurines of Venus and small, delicate knives that first appeared in what are now Austria, the Czech Republic and the northern Balkans. But Prof. Blaffer-Cohen points out that at the time there were many cultures in Europe, they existed in fairly overlapping geographical areas, and therefore it is difficult to link genes to a particular culture.
The genetic data indicate that at the height of the last ice age, 24 to 16 years ago, the people of the Aurignacian culture were concentrated in a shelter in Iberia and Ukraine. The people of the Gravatian culture probably moved to the Balkans. After the glaciers retreated and the climate became more relaxed, they came out of the shelters and quickly dispersed to the rest of the continent.
However, some scientists said that the link that Prof. Underhill and his colleagues made between cultures known from archaeological evidence and roughly dated mutations is problematic. "I think they are right," said Prof. Underhill. "We are at the beginning of the journey, and we still don't have quite good dating methods. But in any kind of historical investigation you have to look at as many pieces of the puzzle as possible. Science moves forward from observations of facts and the interpretation of facts. Science is a self-correcting process, so if a wrong interpretation was made, someone else will eventually obtain new data or new observations and reinterpret."
{Appeared in Haaretz newspaper, 15/12/2000}. The knowledge site was at that time part of the IOL portal of the Haaretz group.
The theory of rivers
These findings remind the author of a theory about the reasons for the division of man into different regions
(Published in the science forum at IOL)
By Baruch Tivon (word of opinion)
Interesting findings, interesting if they can be linked to a suspicion I have on the subject. As we know, there are 5 racial groups of humans, European, Asian, which are the young, the African or Congolese which is the old, and the aborigines and the Hottentots + perfumers of Dr. Africa. An important characteristic of these groups is their quantity, the first 3 BC are the largest, while the last 3 are the oldest.
When you look at the map of Africa, 5 rivers stand out, Orange, Zambezi, Congo, Nile and Niger. The last 3 are the largest and also the furthest from South Africa, the place where the earliest fossils of us were found. My suspicion is that there is a correlation here, each Kb wondered around a different river.
The possible scenario is that the Congolese, moved north to the Congo, and near each river a part separated and became a different community. After the Congolese settled in the Congo, they separated and moved north, forming the Asian and European tribes. If the Asian originates from a group that wandered around the Nile, then on its way to Asia, a left turn to Europe was also open. The problem is that the European group accepts the Niger and here an immigration route from North West Africa to Europe needs to be found.
