This is the fourth in a series of “who am I?” posts. My curiosity is a factor of aging. Now that I’m no longer distracted by professional challenges, family duties or the need to earn a living, I find myself pondering more and more the wonder of being human in this amazing world. How is it that I fall asleep for eight ours each night and waken in the morning, oblivious to what’s happened during the night? How do I continue breathing twenty-four hours a day, even though “I” am not doing the breathing?
Recently I started wondering about how we, as the human race, developed.
If you’d asked me about my ancestry a few months ago, I’d have told you I’m the result of a long line of blond, blue-eyed men and women. My light-skinned forefathers and foremothers immigrated to Canada from England, Ireland and Scotland. They chose to settle in southwest Ontario. End of story.
That was before I sent my cheek swab and $100 to the National Geographic’s genome study. For my $100 they told me about other ancestors: those who predated written history.
Here’s what they said: My ancestry began in Africa. In fact, our whole human race originated on that warm continent. My particular group of ancestors migrated out of Africa around 60,000 years ago. They were the first group of modern humans to leave Africa. These early members of my tribe, who had dark skins, kept moving northward, eventually leaving the African continent completely. When they got to Europe they found a world that was covered in ice sheets. As the ice retreated they settled in whatever European lands were now habitable.
Life in a cold climate had its problem. Their dark skin blocked out too much of the weak sun’s vitamins. Over time, in order to survive in the cold their skin grew lighter and lighter so they could absorb Vitamin D.
Narrow noses replaced flared nostrils since breath had to be warmed before it hit the lungs. Of course, their relatives who remained in hot countries kept their dark skins and their physical adaptations to a hot climate.
78% of my ancestors ended in Great Britain and Ireland. 16% went to western and central Europe. The fascinating thing is this: my ancestors (and probably yours) weren’t the only inhabitants walking about on two legs. Our ancestors met with another hominin group, the Neanderthal. These two lines interbred. That’s how I ended up having a DNA of 1.2% Neanderthal. If your ancestors left sub-Saharan Africa for Europe and Asia, you too have some Neanderthal in your DNA. 2.1% is average. Interestingly, early humans who stayed in sub-Saharan Africa and did not migrate, have no Neanderthal DNA.
Other than finding I had Neanderthal ancestors in my lineage, there weren’t any big surprises: 12% Scandinavian, 9% Central European, 5% Southern European, 2 % Eastern European and 2% Jewish Diaspora.
Knowing the scientific history of our human species is important. How can we be racially biased now that we realize the colour of our skins results from adapting to the climate in which our ancestors lived? If some people remained dark-skinned in order to survive the blazing sun, while pale skinned people evolved to absorb sufficient energy from the sun, where’s the social judgment? We’re all the product of the human race’s ability to adapt in order to survive.
I’d like to hear from you. What do you think? Are you interested in having your own DNA analyzed? If you are, you can go to www.genographic.com.