Thanks to genomics, we can dive into the past of the human race, better understand the lives of our ancestors, and learn the reasons why they migrated from one place to another.

In this interview with the French newspaper Nouvel Observateur, anthropologist Evelyne Heyer, author of L'Odyssee des Genes, says that DNA has been a universal memory for living organisms since the emergence of single-celled organisms 3.5 years ago. Billions of years, all the way to humans.

History of each type

Haier explains that monitoring the differences between nucleotides enables tracking of the history of each type of organism separately, knowing the periods of their growth and degradation and the nature of their migrations.

With regard to the extent to which genetic mutations are related to the laws of evolution resulting from the adaptation of species to their environment, the researcher believes that these mutations occur without a goal or purpose, as they are simply “errors in the reproduction of the genetic code. If these mutations are harmful, then they disappear, but if they are useful, they continue across generations. But most of them are neutral and have no particular benefit.

And for humans specifically, Haier says, scientists have been surprised by the discovery of the low number of genes linked to the beneficial mutations that distinguish us from our closest ancestors.

This indicates that the human mind is not the product of a series of evolutionary mutations, as we think.

The Nature of Human Migrations

In response to a question about the nature of the first human migrations, Haier says that our ancestors moved very slowly, maintaining a distance of a few miles between them.

Monitoring the mutation rate allows tracking of the period in which human groups disintegrated, geographically.

By comparing the genome of modern African populations with those of other continents, scientists were able to trace the path of human migrations.

After leaving Africa about 70,000 years ago, humans did not reach northern Europe until 30,000 years later, which means walking at a rate of 3 kilometers per generation.

Archaeologists and anthropologists have long wondered about the arrival of humans in Australia, and could it have been done on foot?

By redrawing the map of the ancient world and sea currents, the researchers discovered that the nearest land point to reach Australia required crossing a sea of ​​about 50 kilometers, and they concluded that the first mass sea crossing occurred during that period, although the number of adventurers there was not enough to withstand the time long.

From studying the genome we were able to trace the course of human migrations (Urotsig - Wikipedia)

Demographic growth of the human race

And about the potential impact of demographic pressure on humans' continuous search for new areas to live, Haier emphasized that humans did not reproduce in large numbers millions of years ago, as is the case with great apes that were 10 times more than humans.

The period in which man left Africa, about 70 thousand years ago, was not characterized by a large population growth, but on the contrary, it witnessed a decline in the number of people.

Haier adds that the number of people was increasing as the resources increased, so a population boom occurred with the emergence of agriculture in different parts of the world about 10 thousand years ago.

With the settlement in agricultural areas, human groups began to benefit from crops periodically, food diversified and the number of births increased.

With regard to the unprecedented decline that humanity is currently witnessing in the birth rate, Haier confirmed that this dangerous phenomenon is still going through in the shadows due to the high rate of life at birth, which relatively limits the rates of demographic decline, but this is not hidden in countries experiencing aging rates. Accelerated.

The French researcher expects that the world population will shrink after reaching a peak of between 9 and 11 billion people.

In light of the tightening of immigration procedures between countries, Haier says that this will not stop the movement of people from one place to another, but it will only make migration conditions more miserable.

In her opinion, "We must not overlook that all of our ancestors were immigrants, as our DNA shows."