WHAT IS THE MONOGENIC THEORY OF HUMAN ORIGIN? - HISTORY - 2025

The monogenic theory of human origin explains that the human being as we know it today has a single and common origin. This theory reveals that Africa was the place where Homo sapiens originated; from there they began to migrate in several waves to different parts of the world.

The name is of Greek origin, "monkey" means one, while genista comes from "genesis" which means birth. It could be translated as “unique birth”. According to this theory, each human race had the same African origin and various factors were those that modified their physical characteristics.

Map of places where fossils of the first hominids have been found.

It is the most accepted theory about the origin of Homo sapiens, being contrary to the polygenic theory of human origin. This establishes that Homo sapiens come from different racial lineages.

The common origin theory does not have a single author who has formulated it. In reality, this has been the result of multiple investigations by scientists, anthropologists and historians.

The investigations that gave foundation to this theory were based on some Darwinian ideas extracted from the book "The Origin of Man" published in 1873.

Ideas that formed the monogenic theory of human origin

There were two thoughts of Charles Darwin that gave basis to the people who would later formulate the monogenist theory. His first thought was this:

"It is inadmissible that the modified descendants of two organisms, which differ one from the other in a marked way, can later converge to such a point that their organization as a whole is almost identical."

And the second, perhaps more renowned, was this:

"Naturalists, who admit the principle of evolution, like most of the more modern ones, find no difficulty in recognizing that all human races come from a single trunk first."

Darwin created at the time the theory of the common ancestry of the species. It wasn't just about humans, nor did it establish what the common origin was. He took as a reference the similarity of many species and determined that in order to be so similar they must have a common ancestor.

To defend his two positions on the common origin of human races, he explained that external visible differences do not constitute the human being. The human structure has an innumerable amount of similarities, beyond the external aspect.

Therefore, for Darwin it was impossible for all these structural characteristics to have been developed independently by each race. Finally these characteristics were similar or equal to all the others.

Africa, the cradle of humanity

The formulation of this theory took shape when various researchers came to the conclusion that it was in Africa that Homo sapiens was born.

The origin of all races was African and due to climatic changes, certain “racial” traits were distinguished. It occurred approximately 120,000 years ago.

There are two discoveries that form the basis of the theory: Grimaldi man and mitochondrial common ancestry.

Mitochondrial African Eve

The discovery of mitochondrial Eve is the biological basis for this theory. It was the one that shaped the consideration of a common racial ancestor and that this was African.

Mitochondria are DNA sequences found outside the cell nucleus. But, unlike chromosomes that are given by both parents, mitochondrial DNA is inherited only from the mother.

Three researchers came up with the discovery of "Eva": Rebecca Cann, Allan Wilson and Mark Stoneking. Following the investigations of WM Brown, who postulated common mitochondrial ancestry, the 3 researchers decided to go further and find out where it came from.

They began to do a series of experiments, extracting DNA from the mitochondria of thousands of placentas of different races: African, Asian, Australian, etc.

They realized that the mitochondrial sequence was the same and with the construction of a phylogenetic tree, showing that all humans are related at the mitochondrial level.

All this lineage of mitochondria brought them to Africa, roughly 120,000 years ago. There he reached the conclusion about the mother of humanity; the mitochondrial African Eve.

This Eva was not a single woman. It refers to several women who were in that certain period of time in the first Homo sapiens of the world.

These women were mothers of migrant humans. Thanks to mitochondria, it was discovered that every human being is related to the same ancestor.

Grimaldi man and physical change for adaptation

This discovery occurred in Italy and it involved two skeletons. These gave a new division to human evolution, calling them Grimaldi Men.

When analyzing the skeletons, they found a structure almost identical to the Negroid. However, the structure of the forehead and nose had completely "European" features.

Multiple proponents of that theory, especially the anthropologist Cheikh Diop, explained that it was proof of the migration of African man to Europe.

The Negroid structure but with slight changes, suggested the adaptation of African man to the climate and conditions of the north of the world.

The Grimaldi man had changed to survive the colder environment; to later become what today is "the Caucasian man." Another defense of the monogenic theory is that nature has never created a being twice.

The detractors of the theory are based on the fact that it is impossible that external factors could have conditioned the physical aspects and that it is admissible that the races have had their own origin separated from the others.

Bears as evidence of physical and evolutionary change

An example of whether these changes are possible is the case of the polar bear and the brown bear.

Following Darwinian theories, all bears come from a common ancestor. In fact, science indicates that Polares and Pardos were the same species, until about 400 thousand years ago.

Although the direct link between these two species of bear can be found, physically they are very different. Nature did not create different species of Bear, the species evolved from the same ancestor.

In reality, it is thought that the brown bear went to the Arctic and adapted to the climatic conditions there. As a result of this adaptation process, it became the polar bear. His coat changed and his jaw changed to adapt to the food and climate of the Arctic

References

1. Diop, C "The African origin of civilization: Myth or Reality" Issue N ° 30 (1989) Lawrence Hill. U.S.
2. Darwin, C "The Origin of Man" PDF Retrieved July 18, 2017 from books.google.com
3. Hirst, K (2017) "Out of Africa Hypothesis - Did All Humans Evolve in Africa?" Retrieved on July 18, 2017 from thought.co
4. (2014) "Population Genomics Reveal Recent Speciation and Rapid Evolutionary Adaptation in Polar Bears" Retrieved on July 18, 2017 from cell.com
5. "Origin of modern humans" Retrieved on July 18, 2017 from wikipedia.org
6. "Grimaldi Man" Retrieved on July 18, 2017 from en.wikipedia.org
7. Khan Academy "Where did humans come from" Retrieved on July 18, 2017 from khanacademy.com
8. Yin, S (2016) "Why Do We Inherit Mitochondrial DNA Only From Our Mothers?" Retrieved on July 18, 2017 from nytimes.com
9. Gitschier, J (2010) "All About Mitochondrial Eve: An Interview with Rebecca Cann" Retrieved on July 18, 2017 from journals.plos.org.