Skin Deep

Imported from my former Tumblr blog.  Originally posted 05/11/11.

The differences between us are more than what is visible.  You can certainly look at someone and say,"They have very dark skin, they must be from Africa" or,"They have a single eyelid, they must be Asian".  What some people forget is that there are far greater biological differences between us that go beyond body shape, skin tone and facial structure.

I'm not talking about the intrinsic individuality that all humans undoubtedly have.  Of course we are all different.  People make different decisions which lead to individual outcomes and we posses unique personalities, just to name a couple.  What I am talking about are biological differences that many people aren't aware of when discussing differences among races.

This entry stems from numerous conversations that I would have with my mother.  Being that I live in Canada and not on the west coast, I am able to witness the annual event which is a cold winter.  I'm not even going to get into the discussion of where winter is coolest or how I have no right to complain because I don't live in an exotic place such as Siberia or the high Arctic.  I think it is an accurate guess if I am to say that the temperature variance between the hottest summer days and coldest winter days is around 50 degrees Celsius (-20C-30C).  Those would be true temperatures and don't take into account the Humidex or Windchill.  Well, whenever it's winter here I am miserable.  It's not the snow that bothers me, but rather the decrease in daylight hours and the straight to the bone cold.

No, I'm not whining.  That's what my mom always used to tell me, "Suck it up, you've lived here for so many years.  You were born here!".  And I honestly tried.  I wore more layers thinking that maybe I wasn't dressing properly.  I slept earlier and exercised so that I would have more energy.  Imagine my disappointment when I would go places and find that compared to everybody else I was dressed in double the layers, or that no matter what I couldn't keep my eyes open when it was dark outside.  My mother continued to shake her head and I began to think that maybe there was something wrong with me.

I heard a catchphrase on a t.v. show once, "I have a low core temperature".  Is that even possible?

For a while I believed that maybe I just have a low core temperature, or perhaps poor circulation.  Unfortunately the thermometers told me that my body temperature was right where it should be, and the doctor told me that I had a very healthy heart.  Thank goodness that the heart is healthy!

The reasoning behind the television characters nonchalant declaration that he had a low body temperature was that he is Hispanic.  He claimed that having family heritage and having grown up in a warmer environment caused his body to adapt and that it was perfectly normal and natural.  I figured this was just a fantasy, another over exaggeration written for television. Turns out that he was onto something.

I was sitting in my first year biology class when something the professor said caught my attention.  We were on a unit talking about chromosomes and introductory genetics.  We had just gotten through a section talking about the factors that determined skin tone (interesting enough by itself).  Later in the lecture the professor went on to say that there had been a recent study which proved that those with recent heritage from tropical environments were more susceptible to cold.  Take that mom!

As it turns out, northern human populations have developed a biological adaptation to help them deal with the colder environment.  I'm talking about something beyond the development of clothing.  These populations over time developed a specialized form of fat, I believe the professor referred to it as a type of brown fat.  This is a healthy fat, not the same type of fat that we talk about when we discuss obesity and overweight populations.  This fat acts as an insulator.

It was found that in populations living in tropical or very warm environments that this fat had disappeared from the population. Of course, if someone immigrated from a northern climate to one of these warm climates, they would still posses the insulating fat.  Furthermore if someone moved from a warm climate to a cold climate their genetic line would eventually develop this type of fat.

Could this possibly be used to explain why I can't tolerate the cold very well?  Being that I am half Jamaican, perhaps I didn't immediately inherit the insulating fat.  My mother however has lineage from North-Western Europe and perhaps that is why the cold doesn't bother her... as much.  Unfortunately I wasn't able to find any articles about what I just wrote.  I didn't search very hard mind you, but I'm not even sure of the scientific name of the brown fat so I'm not sure I would be able to find it anyways.

So there we have it, an example of how we are all different beyond the visual evidence. Another difference that I am aware of is that those with darker skin require more exposure to sunlight because they are not able to absorb vitamin D as quickly.  I'm sure many of you were are that darker skin is an evolutionary adaptation to offer protection from the sun.  This is why darker skinned races typically have origins in tropical areas, where daylight consistently hovers at around 12 hours per day instead of fluctuating as it does further towards the poles.  In order to get enough vitamin D, those with darker skin tones require up to 20 times more sunlight exposure in order to get the required daily amount of vitamin D.

These are the challenges I am faced with as a person with darker skin and tropical heritage.  Challenges here go beyond the typical social troubles that minorities and majorities come to expect.  By examining simple biology, it is nice to be able to gain an explanation of why things are the way they are.  Those of us with dark skin weren't given dark skin as a holy punishment (I choose to believe), but rather as an advantageous adaptation in the warm environments we all love.