Christian Long

Nina Jablonski: Breaks the Illusion of Skin Color

In TED Talks on April 18, 2010 at 5:50 pm

Reflection by GABRIELLA B.

Original TED page w/ speaker bio, links, comments, etc:

Nina Jablonski:  Breaks the Illusion of Skin Color

Now, what do you think of when someone says the word Evolution?

The first thing that comes to mind is probably Charles Darwin. You remember, right? Repetitive passages in biology text books on natural selection and survival of the fittest, perhaps a few paragraphs in some dusty history class on his book, On the Origin of Species. You’ve probably seen the overly dramatized cartoons of Darwin with a monkey’s body. And heard outraged creationists renounce the heretical idea that they were ever descended from monkeys.

But really Darwin, throughout his life said little about the evolution of humans. In fact his famous work On the Origin of Species has only one line pertaining to humans. It very ambiguously states, “Light will be thrown on the origin of man and his history.”

Whether or not you are creationist or evolutionist, atheist, god fearing, or not, As Nina Jablonski delves into the mystery of human skin tone, she explains the scientific and medical reasoning for our varied sepia hides.

Remarkably, although Darwin did take note of the varied skin tones of humans throughout his travels and stated that, “of all the differences between the races of men, the color of skin is the most conspicuous and one of the best marked.” He followed this with, “These differences do not coincide with corresponding differences in climate.”

Now whether this exceptional forward thinking, intellectual and observant man was simply falling under the unfortunate mind-blank society imprints upon us all or a genuine oversight we may never know. However with new technologies we now, not only understand, from observation that humans in tropical climates have darker toned skin than those in cold, but have NASA satellite imagery of the annual ultraviolet radiation earth receives.

From this it is clear that not only is there a direct link from human skin tone to climate but also that our skin has developed as it has in order to protect us from the three types of dangerous ultraviolet rays. UVC rays which are all filtered by our atmosphere as well as UVA and UVB which are not.

This is because in areas both north and south of the equator, near the poles, sunlight reaches earth at an angle, passing through a thicker layer of atmosphere than at the equator, this means that all or most of the dangerous UVB radiation has been filtered out. Unfortunately UVB is also the necessary catalyst for the development of vitamin D.

People who inhabit equatorial areas have dark skin pigmented and protected by melanin, much like our earliest ancestors who inhabited Africa. They have remained unchanged over the millennia unlike their northern counterparts whose skin has lightened as their changing environment demanded, producing less melanin in order to better absorb the necessary amounts of UVB rays.

Now how does all of this affect us today?

We as a society like to think that we are not blinded by stereotypes of race. As we were in the earlier centuries of our development and whether that is true or not many factors in recent and less than recent times have caused huge shifts in population all over the world.

The trans-Atlantic slave trade, similar Caucasian colonization of Africa and Asia, all these are historical examples of people adapted to high UV environments moving to low and vice versa. Present day technologies that allow us to cross continents over night have played no small role in this generous genetic mixing.

But this mix of skin tones across the globe has had a consequence on our health. Lightly pigmented peoples must be wary of sun burn and skin cancer very obvious problems, but this is not the only draw back, darkly pigmented people can suffer from vitamin D deficiency and the whole host of problems that brings on.

So what ever you take away from this, be it a new way to explain and understand evolution’s process of natural selection, or an interesting tidbit about health. Light and dark we can all appreciate the technological advancements in health and science that have allowed us to better understand the delicate environment we inhabit.

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