Themes > Science > Life Sciences > Human Races > The Biology of Race


(A Piece of Melanin)

In modern day society, the concept of race is a widely accepted quality of humans.  Race is characterized by the color of an individual’s skin color and their ancestry.  The former, most widely recognized as an indication of one’s race, is accompanied by the presumption that the genetic and biological causes responsible for it, originate from people with a great degree of genetic variations within the human species.  But what is the relationship between skin color and genetics?  Is it important enough to divide humans into separate races?  Does the term race have any scientific merit or is it a manifestation of social stratification?

Phenotype and Genotype

According to James King, author of The Biology of Race, Physical characteristics such as hair color, eye color, height, skin color, build, etc., are the components that make up an individual.  These are the observable characteristics that can be inferred as inborn qualities. From these qualities we assume that the traits are inherited from the parents.  The genotype is the genes that are directly given to the offspring, and the phenotype is the consequence of those genes. For example, we can assume that an individual with blue eyes has received the blue eye color gene from both parents and no genes for brown eye color, because brown is a dominant gene and blue would not be observable.  So the Genotype of blue eyes is two blue eye genes and the phenotype is the blue eyes that we can see (King 111-114).
People of European dissent tend to embody a variation of skin color.  Variation within groups is as strong as the socially recognized variation between ethinicities.  There seems to be a direct relation between parents and their offspring.  When two parents of similar phenotypical pigmentation produce offspring.  The offspring usually embody the sane color.  However, unlike eye color, phenotypically dissimilar pigmentation produce offspring, that offspring tends to be intermediate.  Oddly enough, when two of these intermediate parents produce offspring the result is often to the extreme of the original parents (King 212).
Pigmentation also has a key environmental factor, writes L.C. Dunn author of Heredity and Race (315).  When individuals with pale skin color are exposed to long periods of direct sunlight the result is darker skin.  As the original skin color gets darker the effect of exposure to the sun diminishes.  The darker the skin the greater the resistance to the damage the sun can cause.  Hence, the minimal need for darkly pigmented people to darken.  In this instance it is difficult to infer genotype from phenotype (315).

The Geography of Race

It is hard to ignore the fact that the different proposed races of the human species have originated in separate isolated regions of the earth.  And where crossroads have been formed between these regions a blend of the races has developed.

There are three factors of geography that may be attributed to race (Dunn 315-321).

        1. Physical barriers such as mountain ranges, oceans, desert regions, etc.
        2.  The effect of geography on climate which leads to the variations within species.
        3.  Of less impact are the chemical or mineral variations in terrain and soil.

Physical barriers keep interbreeding between different regions to a minimum.  They restrict the movement of genes from spreading to other populations.  In prehistoric times, the ability of human kind to break these geographical barriers was small.  Once established in an area, years of isolation lead to a variation within that population that other populations would not have had access to (318).  These factors in racial variations had a direct impact on the next two.
Climate has a direct effect on the pigmentation of races.  In areas where peoples were exposed to more direct sunlight, skin pigmentation becomes increasingly darker.  As stated earlier, the skin develops darker pigmentation to effectively protect itself from the sun.  In areas where less sunlight is experienced, the skin does not develop this quality genotypicaly, but embodies the ability to adapt rapidly when exposed to the sun (Dunn 315).
Skin pigmentation is determined by the amount of melanin present in the skin.  The more the melanin the darker the skin.  All races of the human species have this characteristic.  There are isolated instantances of albinos, which are present in every race. This is a genetic mutation that lacks any pigmentation in eyes, hair, and skin (King 114).

In subtropical areas, where tree cover is scarce, such as the African Savannah, the people living there develop extremely dark pigmentation.  In southern Asia, the sun exposure was consistent but it was not as strong and tree cover was present which caused the people’s skin to darken to a lesser degree.  In European areas, the cloudy cover enabled the people to survive without this quality.  As you move further north into the Arctic region, the sun becomes stronger and the glare off the snow mix to create a people more similar to the Asian people ( Dunn 318-320).
The third factor of chemical or mineral variation in the terrain is quite complicated and best understood by a simple example.  In New Zealand, the natives centuries ago had a legend of the “good lands” and the “ bad lands.”  In the bad lands, the cattle and people were often struck with a sickness, today identified as pernicious anemia.  The anti-pernicious factor in humans is a compound of cobalt and in areas where the sickness occurred, cobalt was minimal in the soil.  This further prevented the movement of people (Dunn 320).

Races or Variations?

The presumption that there are a number of different races within the human species implies that there is a different genetic code for these separate races.  King explains, the degree to which the genetic makeup between individuals in different racial categories varies is 6%.  However, within any certain race there is the same degree of difference between individuals.  The development of varying skin pigmentation is not an influential enough of a difference to divide the human species into races.  Skin color is merely a reaction to a dangerous environment.  The same instances have been documented in immunity to diseases.  A people who are endangered by a virus develop a way to survive (Boyd 45).
It can also be argued that the geographical factors stated above are the same factors that have been responsible for the evolution of all species.  Nature and its woes had an influence on the variations that were experienced by the people.  But the amount of time that it takes for a new species to develop is immense.  Human beings started to expand out into the world about 25,000 years ago.  This leaves little space for the evolution of separate species.  At this same time, the people were beginning to develop technology.  It was rather primitive, but its purpose was to make survival easier.  Humans are the only animals that do not adapt to the environment, but rather adapt the environment to fit their needs.  So, with a brief period, being subject to nature, humans adapted to their environment physically, but with the quick advancement of technology the impact of nature became minimal (Dunn 48-51).
Race can also be examined from the angle of interbreeding.  For example the Drosophila. A species of flies. Has a number of documented strains.  When these strains are interbred, fully fertile and sometimes even larger flies are produced.  Yet, when these hybrids reproduce, their offspring are prone to genetic defects and infertility. Further breeding of these offspring leads to more extreme cases of the same.  This scenario has been documented in many different animal species (King 118).
This type of genetic divergence is nonexistent in the human species.  To be classified as separate races, humans would need to possess this hybrid disability.  The “races” of the human species are variable in degrees of melanin, which does not qualify them to be called as such.

Race is a concept of society that insists there is a genetic significance behind human variations in skin color that transcends out ward appearance.  However, race has no scientific merit outside of sociological classification.  There are no significant genetic variations within the human species to justify the division of “ races.”


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