The Monogenistic theory of human origin Explains that the human being as we know it today has a unique 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 genist comes from"genesis"meaning birth. It could be translated as"single birth".
Map of places where fossils of the first hominids have been found.
According to this theory, each human race had the same African origin and various factors were those that modified their physical characteristics.
It is the most accepted theory about the origin of Homo Sapiens , Being contrary to the Polytechnical theory Of human origin. This establishes that the Homo Sapiens come from different racial lineages.
The theory of common origin does not have a single author who formulated it. In fact, 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 monogenistic theory of human origin
There were two thoughts of Charles Darwin That gave base to the people who soon would formulate the monogenista theory.
His first thought was this:
"It is inadmissible that the modified offspring of two organisms, which differ from one another in a marked way, can then converge to such an extent that the whole of their organization is almost identical."
And the second, perhaps of more renown was this:
"Naturalists, who admit the principle of evolution, like most modern ones, find no difficulty in recognizing that all human races come from a single trunk first."
Darwin at the time created the theory of the common ancestry of species. It was not anything more than 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 should have a common ancestor.
In order to defend his two positions on the common origin of human races, he explained that visible external differences do not constitute the human being. The human structure has an innumerable number of similarities, beyond the external aspect.
Therefore, for Darwin it was impossible for all these structural characteristics to be independently developed 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 several researchers came to the conclusion that it was in Africa that the birth of Homo sapiens was born.
The origin of all races was African and due to the 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: The Grimaldi man and the common mitochondrial ancestry.
The African Mitochondrial Eve
The discovery of mitochondrial Eve is the biological basis of this theory. It was the one that shaped the consideration of a common racial ancestor and that this was African.
The Mitochondria Are DNA sequences that lie outside the cell nucleus. But, unlike the chromosomes that are given by both parents, mitochondrial DNA is inherited only from the mother.
3 researchers came up with the discovery of"Eve": Rebecca Cann, Allan Wilson and Mark Stoneking. Following the research 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 make a series of experiments extracting DNA from the mitochondria of thousands of placentas of different races: the African, the Asian, the Australian, etc.
They realized that the mitochondrial sequence was the same and with the construction of a phylogenetic tree, demonstrating that all humans are related at the mitochondrial level.
All this lineage of mitochondria took them to Africa, approximately 120,000 years ago. There came the conclusion about the mother of humanity; The African Mitochondrial Eve.
This Eve was not one woman. It refers to several women who were in that particular space of time in the first Homo Sapiens of the world.
These women were mothers of migrant humans. Thanks to the mitochondria, it was discovered that every human being is related to the same ancestor.
The Grimaldi man and physical change for adaptation
This discovery occurred in Italy and it was 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 negroide. However, the structure of the forehead and nose possessed completely"European"features.
Multiple advocates of this theory, especially the anthropologist Cheikh Diop, explained that it was a proof of the migration of the African man to Europe.
The blackish structure but with slight changes, meant the adaptation of the African man to the climate and the conditions of the north of the world.
The Grimaldi Man had changed to survive the colder surroundings; To then become what is now the"Caucasian man".
Another defense of the monogenist theory is that nature has never created a being twice.
The detractors of the theory are based on that it is impossible that the external factors could have conditioned the physical aspects and that it is permissible that the races had their own origin separated from the others.
Bears as proof of physical and evolutionary change
An example of whether these changes are possible is the case of Polar Bear and Brown Bear.
Following the Darwinian theories, all the bears come from a common ancestor. In fact, science indicates that Polares and Pardos were one species, until about 400 thousand years ago.
Although the direct link between these two bear species can be found, they are physically very different.
Nature did not create different species of Bear, the species evolved from the same ancestor.
In fact, it is thought that the Pardo bear went to the Arctic and there adapted to the climatic conditions. As a result in that process of adaptation, it became the Polar Bear. His coat changed and his jaw too, to suit the food and climate of the Arctic
References
- Diop, C"The African origin of civilization: Myth or Reality"Issue N ° 30 (1989) Lawrence Hill. U.S.
- Darwin, C"The Origin of Man"PDF Retrieved on July 18, 2017 from books.google.com
- Hirst, K (2017)"Out of Africa Hypothesis - Did All Humans Evolve in Africa?"Retrieved on July 18, 2017 from thought.co
- (2014)"Population Genomics Reveal Recent Speciation and Rapid Evolutionary Adaptation in Polar Bears"Retrieved on July 18, 2017 from cell.com
- "Origin of modern humans"Retrieved on July 18, 2017 from wikipedia.org
- "Grimaldi Man"Retrieved on July 18, 2017 from en.wikipedia.org
- Khan Academy"Where did humans come from"Retrieved on July 18, 2017 from khanacademy.com
- Yin, S (2016)"Why Do We Inherit Mitochondrial DNA Only From Our Mothers?"Retrieved on July 18, 2017 from nytimes.com
- Gitschier, J (2010)"All About Mitochondrial Eve: An Interview with Rebecca Cann"Retrieved July 18, 2017 from journals.plos.org.