The notion of race is still in good health in popular terms. We are talking about breeds of dogs and cats, purebred horses and black or white men and women.
Classical anthropology , heir to the ancient conceptions by which humans around the world were classified into categories, sustained the existence of five races , distributed by region: African , Asian , European , Native American , and Oceanic . The classification took, as a starting point, the observable traits of individuals (phenotype), such as skin color and height .
The problem is that, although it has a historical tradition and is reflected in common use, the concept of race , at least applied to humans , does not withstand exhaustive scientific analysis.
Since the 16th century , the subgroup, within the same species , that has certain observable traits transmitted from parents to children, has been called a race . Associated with nationality and ethnicity , the idea became very popular in the 19th century , when attributes such as intelligence and character were added to the physical characterization of races .
Scientists like the American doctor Samuel Morton went down in history for establishing the idea of racial hierarchy : some races were superior to others, more intelligent and good . Morton , considered the father of ” scientific racism “, considered that humans of the white race ( Caucasians ) were at the top of that hierarchy , while the black race was the worst endowed.
This class of pseudoscientific theories mixed the social position occupied -for cultural reasons- by some human peoples, with measurements of the internal volume of skulls from different sources ( craniometry ). A nonsense that, despite not having the minimum scientific seriousness, served to justify slavery and segregation .
With the advent of the 20th century and the advancement of genetics, we were able to begin to learn more about how differences are produced and inherited . And it seems increasingly clear that the concept of race is more of a social and arbitrary construction than a valid scientific concept.
If there were indeed five human races , biologically speaking, the individuals originating from each region would have to have a relatively uniform genetic identity . Those putative races would form separate categories , and we should be able to find enough genetic variation among such races to confirm this.
In addition, there should be enough alleles (the different variants with which a gene is expressed) specific to each region, exclusive, that do not occur in other regions .
But it’s not like that. The reality is that we are very mixed .
A 2002 study published in Science revealed that only 7.4% of more than 4,000 alleles analyzed were specific to a geographic region. And, as if that were not enough, they were only present in 1% of the people in that region.
As the research of recent years indicates, each of us can present more genetic variation compared to people of the same origin than compared to people with very different external features. For example, two people of European descent may be genetically more similar to an Asian person than to each other. Something that, of course, completely blurs the concept of race associated with genes.
Current scientific evidence tells us that visible differences between people from different regions are rather accidents of history, not justifying biological classification into races . Differences that, as striking as they may be, reflect adaptation to the environment , and are an expression of how our ancestors dealt with exposure to the sun, the environment , and geography . But not much else.
Our case, Homo sapiens sapiens , is very different from that of “purebred” dogs , much more genetically similar to each other than to dogs of other breeds. Humans, in fact, have a more common genetic repertoire between individuals, regardless of our origin, than any other primate .
And if we insist on looking for genetic differences between humans, the biggest differences are not in our skin color: there are more genetic differences between humans in Africa (such as the Khoisan and the Pygmies , who were separated for tens of thousands of years) than anywhere else. of continents together.
Human beings present different external features that, over time, we have accumulated by evolution . It would be absurd to deny the differences in our skin color, height , hair and eye color, etc., since they are obvious and largely correlate with latitude .
The question is: is there any use in making classifications in this sense? It seems that yes, although, more than paying attention to the visible features, it will be necessary to attend to the genetics of the individuals.
Currently, the scientific concept that is beginning to replace the imprecise notion of the human race is “ genetic ancestry ”, something like a family tree of human populations, rooted in Africa .
One of the fields of study that benefits from the clues of the genotype is that of biomedicine , where handling a certain technical definition of populations is useful to investigate and prevent diseases that have a greater presence depending on which genetic profiles.
References:
Bhopal, R. 2007. The beautiful skull and Blumenbach’s errors: the birth of the scientific concept of race. Bmj, 335(7633), 1308-1309.
Fujimura, J. H. et al. 2011. Different differences: The use of ‘genetic ancestry’versus race in biomedical human genetic research. Social Studies of Science, 41(1), 5-30. DOI: 10.1177/0306312710379170
Rosenberg, N. A. et al. 2002. Genetic structure of human populations. science, 298(5602), 2381-2385.
Tishkoff, S. A. et al. 2004. Implications of biogeography of human populations for’race’and medicine. Nature genetics, 36(11), S21-S27.
Yudell, M. et al. 2016. Taking race out of human genetics. Science, 351(6273), 564-565.
