Unravelling the Mystery of Human Diversity

“None of the observable traits that people associate with race are simple genetic traits. Complex traits are influenced by several genes as well as environment.”
(Jeffrey C. Long, Geneticist)

What is race, really? Try this quiz, offered by the American Anthropological Association:

The answers may surprise you.

Many of us grew with an essentialist view of race. The human population is divided into a number of distinctive groups, which will remain distinctive despite any mixing that may occur with other groups. If you go back in history far enough, you will find the original pure strains of these groups. This view was opposed by Darwin in The Descent of Man in 1871. He postulated that the entire human population, with all its diversity, came from a common gene pool. The essentialist view prevailed because it was a convenient justification for oppressing races deemed inferior, and for practising eugenics, selective breeding to improve the population.

Contemporary anthropologists view race as a cultural invention. Janis Hutchinson, a biological anthropologist, explains: “When you begin to understand the biology of human variation, you have to ask yourself is race is a good way to describe that.” Variations in skin color, height, susceptibility to disease and other characteristics are generated by a complex dance of genes, environment, and cultural experiences. All these factors are under the anthropological umbrella.

Modern anthropologists favor the population concept for describing diverse groups. A race is defined as a cluster of local populations which differ genetically from other clusters. Each member of the population is an individual, but yet shares many characteristics of his or her group. Except in isolated populations, which are becoming more and more rare (perhaps because anthropologists keep studying them, bringing in new influences), the division between members and non-members is arbitrary. Human diversity is a constantly evolving continuum.

Skin color, one of the most visible ways of classifying people, is probably an adaptive trait rather than a racial one. Populations which lived in hot climates replaced their body hair with additional sweat glands. This made them more susceptible to UV radiation. UVR is useful because it helps Vitamin D facilitate the absorption of calcium, but too much of it will strip folate, another essential nutrient. Skin color is the body’s attempt to balance the need for UVR and the need to protect its folate.

Many genetic traits can be linked to geographical adaptation. For example, the sickle cell gene, which is responsible for sickle cell disease, also confers resistance to malaria. Any genetic trait that increases survival until reproduction will be passed on into the genetic pool of the next generation. Evolutionary advantages are not always unmixed blessings.

Anthropologists have been important in catalysing a new understanding of human diversity because they use several lenses to view human development. In the early twentieth century, Franz Boaz, who played a pivotal role in forming the American Anthropological Association, promoted the “four field” concept of anthropology: physical anthropology, linguistics, archeology, and cultural anthropology. He promoted the idea that the biological characteristics, language, and culture of societies are all autonomous areas of anthropology, each equally important to human nature. Margaret Mead and Ashley Montagu were his pupils. In the 1940s, Montagu argued that race was a product of perceptions rather than biological fact. He published Man’s Most dangerous Myth: The Fallacy of Race in 1942, and authored the the UNESCO Statement of Race in 1950.

Darwin’s common ancestor theory has been confirmed by the Human Genome Project, which found that the genetic variations in European and Asian populations are subsets of the variations in the African population. Fossil evidence also suggests that the cradle of humanity was in Africa. There are no qualitative genetic differences between perceived races. We share a common ancestry, and the differences among people are not as great as they seem. While we struggle to assimilate this new information, anthropology continues to explore the mechanisms driving human diversity.

Sources and resources:
American Anthropological Association website about race

Human Genome Project