I find human ancestry fascinating. How are we all related? What did my ancestors look like, and where did they live? What are the stories of our forbearers as they struggled for survival, made discoveries, and lived together?
Adam and Eve were African. That’s not a new discovery, but many people have never heard it. The immediate consequence is that you yourself, regardless of where you come from or where you live now, have African ancestors. The reason that we can be sure of that comes from population genetics.
Here’s a TED Talk that took place in my home-country, Tanzania, that explains in simple terms how you can be sure that you have an African heritage. The speaker is Spencer Wells, who is the director of the Genographic Project. They analyze DNA from indigenous people around the world, building a family tree for the human races. If you want to purchase the kit, you can actually participate in the project yourself by sending in your own DNA for analysis.
Here’s what I found interesting about this talk:
Adam and Eve never met each other. That’s because, by ‘Adam’, I mean the most recent common ancestor of all the men that are alive today (according to the biblical account, ‘Noah’ would have been a better name since all men are said to descend from him more recently than Adam). Correspondingly ‘Eve’ refers to the most recent common ancestor of all the women that are alive today (Noah’s wife).
Now men generally have more disproportionate reproductive success. That is, some men father many children while others father none. For example, Ghengis Khan had so many concubines that it is believed he is an ancestor to more than half the men on the planet (does that explain a lot to you 
?). Women, on the other hand, are generally more evenly reproductively successful. The consequence of this difference between men and women, is that ‘Adam’ appears in our history far more recently than ‘Eve’. So much so, that they lived in completely different time periods and could never have met.
Another interesting realization about Adam and Eve, is that they weren’t the first “humans”. Far from it. The origin of our species dates much earlier, but we defined Adam and Eve as the most recent common ancestors. To find the actual first “humans” is an impossible task, given that evolution works along gradients making only gradual changes. It would be like trying to find the first moment that a child is “grown-up”.
Finally, Adam and Eve lived side-by-side with other non-human bipedal apes. Actually it’s been that way throughout our history. There has almost always been other walking, thinking hominids living with us. It’s a fair question to ask why there’s just our species left now. Did we kill-off, or out-compete the others?
Well, if you find ancestry like this interesting, I highly recommend Richard Dawkin’s book “The Ancestor’s Tale”. It takes you on a journey back to the most recent common ancestors of humans, apes, mammals, vertebrates, and eventually all of life. It’s a beautiful book.
