Human beings have domesticated ourselves, just as we did with other species such as dogs, horses, wheat or corn. Various theories defend that Homo sapiens has taken it upon himself to modify his physical features to show a more friendly face. This has allowed us to evolve as less aggressive and more social beings. However, there is no lack of voices against the idea of self-domestication.
artificial selection
Although it may seem like a modern and revolutionary vision, we are dealing with an idea that Darwin already outlined more than 150 years ago. The term “domestication” has been used in a general way for other species of animals and plants, not for the human being. It is the process by which, consciously or unconsciously, humans have intervened in an artificial selection that has been modifying the species according to our tastes, needs or characteristics that suit us best . For many centuries we have been very proactive in this artificial selection and in a few generations we managed to fix certain traits that benefit us. Charles Darwin, already commented that certain visible tendencies in the species domesticated by the human being were also visible in the own human being. That is why we speak of self-domestication.
The domestication of plants and animals led us to a new stage in the history of the human being: the Neolithic. Although at that time we had no idea what DNA was and there were many years to go before Charles Darwin began to talk about natural selection, logic and the results obtained were enough for us to modify species to our liking. Crossing the individuals that most interested us had a consequence in the offspring: it changed the genetics with modifications that improved the species according to our interests.
It is still somewhat surprising that through crossbreeding we have managed to transform animals from wolves to dogs with dwarfism and exotic shapes that today we have as docile pets with adorable physiognomies. Just as in the opposite direction, we have also created much more aggressive and ferocious-looking dog breeds than the social and intelligent wolves from which man’s best friend came.
More friendly and social humans
This same domestication would have been carried out by Homo sapiens with the individuals of Homo sapiens themselves. That is, according to the theory of self-domestication, the modern human being would have sought to reproduce with the kindest and most social subjects . It would be one more element in our adaptation as a species that has brought us to this point where we dominate the planet.
Several researchers defend the veracity of this evolutionary process through genetic studies. The results conclude that Homo sapiens has self-selected to retain juvenile features, especially in the face, eliminating those characteristics that conferred an aggressive appearance in the adult stage : smaller fangs, tighter ears, a less pronounced snout than usual among Homo sapiens. primates and a less marked supraorbital region. In fact, it is surprising how much the face of an adult Homo sapiens resembles that of an infant Neanderthal . This self-selection would have led to collaborative behavior and groups more inclined to socialize.
Against self-domestication
However, there are those who point to certain fissures in this theory of self-domestication. José María Bermúdez de Castro dedicates an interesting chapter to self-domestication in his book “Gods and beggars”. He points out that domestication changed the physical appearance of dogs, but also their behavior. The faces of Homo sapiens seem kinder compared to the reconstructions we have of Homo neanderthalensis :
“But no one can deny the harsh look and face of many human beings, even though we have lost our snouts and our ears are small. We continue to fight bloody wars ruthlessly, committing genocide, carrying out nauseating political practices or wishing evil on our fellow men. We maintain a certain order thanks to the laws and those who enforce them. Where, then, is our hypothetical self-domestication, in which a peaceful and tolerant character would predominate?”
When we are born we receive an education that could resemble a type of domestication. We are not free to do what we want, unless we want to escape from the system in which we live and take refuge in some forest or Antarctica, in areas isolated from contact with other human beings. But this has nothing to do with domestication and artificial selection, not to say that it would be the completely opposite behavior to the objective that our self-domestication would have pursued.
Therefore, it is possible that we are facing a semi- self-domestication. Well, it is true that our face is more friendly than that of our ancestors, but the changes seem to have been only physical. As for our violent behavior, although we have come far with our societies, wars have not only become less frequent, but as our technology advances, they are more and more devastating. In the words of Bermudez de Castro:
“I bet our brains have a face that would scare us if it could materialize.”
References:
Bermúdez de Castro, JM 2021. Gods and beggars. The great odyssey of human evolution. Criticism.
Theofanopoulou, C. et al. 2017. Self-domestication in Homo sapiens: Insights from comparative genomics. PLoS ONE 12, 10, e0185306.
