Monday, 10 March 2014

We were all black - once !

Skin colour has had a huge influence on how we lived our lives for centuries.  In most cases it delivered an informal type of caste system.   The whiter a persons skin, the higher he or she ranked on the social chain.  Why people have different skin colours was the stuff of interesting legend - and it was often artfully crafted into religious theology.

Charles Darwin, ( 1809 - 1882 ) the great English naturalist created a furore with his theory of evolution.  Since then, science has probed deeper and it seems a proven fact that homo sapiens made the crossing from our less developed ancestors in the Rift Valley of Africa - many thousands of years ago.  It would seem a reasonable conclusion that they were probably black skinned.   It is certainly a fact of life that the people living in the equatorial belt around the centre of planet earth are dark skinned.

Our early ancestors were mainly hunter/gatherers - and they began to explore planet earth.   In the early days they were few in numbers and it took centuries to break free of Africa and now science has a very reasonable explanation as to why we have such a range of colour diversity across this world.

One of the needs for humans to stay alive is for their body to absorb Vitamin D  from sunlight.  Vitamin D is essential to allow us to synthesize the Melanin in our skin to strengthen bones and maintain a healthy skeleton.   Unfortunately, exposure to strong sunlight also leads to various skin cancers and a black skin acts as a filter, regulating the balance and blocking excess.   We know that the lighter a persons skin, the more they are prone to skin cancer, ranging from basal-cell cancers to deadly carcinomas.

It also seems that Darwin was right in concluding that the evolutionary process brings necessary change where it is needed - and this happens over a long period of time.    As the human race moved to northern areas of the planet it experienced colder climes - and much weaker sunshine. The need for covering to shelter from the cold limited the amount of skin exposed for Vitamin D collection.  Our black skin then became a handicap.   It was filtering out too much of the weak sunshine and disrupting the Vitamin D effect.   Evolutionary need kicked in - and out skin colour lightened.

From there - it is pure history.    It was the dominant tribes of cold, weak sunshine Europe who mastered the art of creating sailing ships and invading the rest of the world.   Now we have entered the twenty-first century with a mix of skin colours across every part of this world - and with mixed mating of the world's tribes - it seems possible that sometime in the far future the common world skin colour will be a light brown !

If that eventually happens, it will remove racism from contention - but human nature being what it is - we will surely find another subject to continue the argument !


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