Black Parents/White Baby- A Look at Skin Color, Evolution, and Genetics

Since the slave trade, race and skin color became hot button issues.  But skin color provides an interesting example of evolution and genetics.  Not only does the topic dramatically affect life in American, but one family in Britain is learning a lot about the genetics and impact of skin color.


We know that our skin color will be very similar to the skin color of our parents, which is similar to their parents.  This lineage of skin color travels back far in time.  People whose ancestors come from outside the tropics tend to have lighter skin, while those with ancestors in the tropics have darker skin.  I hope to explain this in more detail in a later post, but it all happens thanks to UV Radiation, Folic Acid, and Vitamin D.  The relationship between these factors creates the skin color kaleidoscope we see on Earth.  We collect these groups of people with similar skin color into racial groups, at the expense of understanding heritage and the true meaning of skin color.


I say this because skin color only exists in the 1mm of epidermis on the surface of our skin.  And even then, skin color only relates to the amount of a special protein, called melanin, that your body produces.  Dark-skinned people have far more melanin than light-skinned people.  Dark-skinned people have more ancestors from the tropics which receives a far greater amount of UV Radiation.


So what controls the production of melanin?  A few genes determine the amount of melanin that your body produces.  Mutations in these genes alter the amount of melanin that the body makes.  The most striking of these mutations is called Albinism.  In albinism, the body produces little to no melanin so the individual appear light-skinned, light-eyed, and light-haired.  There are actually several versions of albinism, which confuses many people.


It definitely confused a couple in England.  A pair of Black Brits, originally from Nigeria, gave birth to a white baby.  The article says that people were confused, and I can imagine that.  Interestingly, albinism occurs more frequently in West Africa than other places.  Because albinism inherits as a recessive gene, neither parent would have known that they carried the gene.  When the egg was fertilized, the baby received both recessive copies and she inherited light-skin from her dark-skinned parents.


Probably a similar mutation occurred in the tribe of humans moving out of Africa and into Europe about 50,000 years ago.  Anyways, the topic of albinism can really go a lot of directions- evolution, racism, sociology, history, genetics, proteins, etc.  It provides a nice discussion topic in a biology class.