SKIN TONE AND THE FUTURE

 

Image of Elizabeth and Olumayowa
Photo: Jamie Langenhan

Imagine you're a bird. Now suppose the place where you live has only very hard nuts to eat, but there is one problem: your beak is as thin as a hummingbird’s. What do you do ? You increase the nu mber of fancy proteins you make and poof: a bigger, stronger beak.


In essence that is the main idea behind the field of evo-devo (evolution and development). It invokes the concept that all organisms look the way they do based not only on DNA but on the environment they live in. This idea applies to all organisms, including you. The way you look is most likely the result of a trait being switched on resulting in a changed feature that is better adapted to the stress of the environment. This explains why people from different regions of the world look unique. Over time certain traits that were turned on were selected.


A perfect example in human beings is skin tone. Depending on the constraints of your environment your skin is either dark, fair, or somewhere in between. If you pay attention to where certain races of people come from, it shows a trend. As you move along the planet’s longitudinal lines, people tend to morph from dark at the equator to light closer toward the poles.

 

Since the human species originated in Africa, it is reasonable to say that we all started out dark skinned. We looked this way because the environment placed certain stipulations upon us. Being newly hairless and living in a region characterized by strong sunlight, we developed a way to protect ourselves in the form of permanent sunscreen. We upped the production of larger, more clumped Melan osomes (tin y black particles that give skin its hue) and tada! UV protection. As the human race began to disperse across the earth’s continents we changed in order to meet the demands of what else, the environment. The farther north or south you travel the less sunlight there is. To obtain the necessary vitamin D from the sun, skin became lighter to allow more sunlight to be absorbed. Hence, you are either pale or dark depending on where you come from.


 

Image of Olumayowa and Jennifer
Photo: Elizabeth Savrann


Life’s ability to adapt to its surroundings is truly amazing. No matter the conditions, an organism has developed a way to survive and flourish. With our drastically changing world, it raises the question of how we will adapt to our new setting. Human creations, like global warming, have already begun to have an impact on nature. How will we fit into this new environment? Already the temperature is rising, the glaciers are melting, and the ozone layer is getting thinner. All these changes have the ability to cue the turning on or off certain genes , and ultimately change the way we look. It will allow the switched on genes that result in the new phenotypes to provide more material for dealing with the stress of the newly changed environment.

 

Since the ozone layer that protects us from damaging sun rays is deteriorating, more sunlight is hitting different regions of the planet. This could explain why the occurrence of skin cancer is dramatically higher than it has been in the past. In order to better survive wouldn’t it make sense that humans should turn darker? Turn up the snazzy protein makers and bam - instant sunscreen? Our future selves will have to adapt to the environment we altered, and turning darker would be a beneficial change.


The irony of this situation is that we caused it, so in theory we are the stimulus to our own metamorphosis. We are creating the selective pressure that will affect the appearance of future generations.


Image of Ru
Photo: Ru Wan

Ru Wan: rw1029 at gmail.com
Elizabeth Savrann: beth.savrann at comcast.net

Last Updated:  24 July 2008