Thursday, 4 April 2013
Different Hair Colors and why they are different
Do you know why web hair have different hair colors? Why is hair comes with four colors, blond, brown, red or black? The ultimate answer, of course, is that hair color is genetically determined, the same as skin color. If your parents and earlier ancestors had black skin and black hair, the odds are that you will also have black skin and black hair. Or, if your parents and ancestors had white skin and blond hair, it is very likely that you will also have white skin and blond hair-unless, perhaps, some ancestors with different color skin and hair slipped into your ancestry at some time in the past.
Having said that, the follow-up question is: Why do humans have different skin and different hair colors? Why don't we all have skin and hair of the same color? The best evidence available to science indicates that humans originated in Africa and migrated from there into the rest of the world over a period of several million years. The only human remains from those millions of years are bones; however, it is hypothesized that these early humans had brown or black skin, since that is the heritage indicated by people living in Africa today. White skin and blond or red hair appears to be a mutational development that occurred within approximately the past 50,000 years, probably in or near Europe. Why did this happen? There is no certain answer to that question yet. However, geneticists who trace human genes throughout human history point out that skin and hair color are traits that are highly likely to respond to the evolutionary pressure of climate. Thus, light-colored skin that synthesizes vitamin D more readily than dark skin in response to sunlight could have conferred a survival advantage in northern climates, where sunlight is weak, as humans moved north along the edge of the retreating glaciers of the Ice Age.1
|different hair colors|