Along with the chromosomes that rearrange themselves every time a new human being is conceived, there is some genetic material which passes unchanged from mother to daughter. It is called mitochondrial DNA. Of course, it can mutate, as does our other genetic material, due to exposure to radiation and to some drugs, but we can learn a lot by studying those mutations.
Every time a mutation occurs, it produces a branching of the human family tree – one branch with the mutation and one without. There are fairly simple methods for finding which mutation occurred before another. So scientists can build up a picture of the family tree.
We can put all the detectable mutations in a time sequence, and give a rough idea of the date when each happened. From the distribution of people with that mutation today, we can get a rough idea of where each occurred. From this we can make an estimate as to where on earth each branch of the family tree first emerged.
That simple use of logic enables scientists to trace how all our sisters’ mitochondrial DNA has mutated over time. Each mutation produces a new branching of the family tree and it is not really surprising that when they have finished putting the whole picture together the human family tree is one tree. Every woman alive today carries mitochondrial DNA that can be traced back to one woman. She lived about 220,000 years ago somewhere in east Africa. It follows that if all our sisters are daughters of that first woman, then we men must also be her sons. You can call her Eve if you like. She was “mother of all the living”.
So the whole human race is literally one family, even if we can’t all trace all the details of how we are related to each person we meet. For example, we don’t deny that we are related to anybody with the same mutupo – even if we can’t trace the relationship exactly.
Our elders would try to identify how closely we are related, especially if it’s a question of a son of one and a daughter of the other wanting to marry, but nobody denies a relationship just because they can’t pinpoint the link. We all know that if I am Soko Murehwa, then everyone whose mother is Soko Murehwa will call me sekuru and their mother will call me hanzvadzi. We recognise we are related and we act accordingly.
We are all members of one African family. Only a very small number of us left Africa and raised families, who add up by now to a large number of descendants, all over the world. That is obvious from the observation that there is more genetic and linguistic diversity among the peoples of Africa than in all the rest of the world. In simple language, that means that some Africans are more different from us than are all the “non-Africans”. No matter what stories we have been told to divide us, we are all one family.
All the evidence suggests that for more than half the history of the human race, we all lived in Africa. Those of us who still live on our home continent might congratulate ourselves on that – and why not? But we need to remember the rest of the human race, the diaspora, are still our family. They aren’t as different as the colonialists, or some of our own elders, would have us believe. And I hear some Chinese are trying to claim on the evidence of some old bones that they are not the same species as the rest of us, but that mitochondrial DNA proves them wrong. We are all one family.
So why can’t all the children of African Eve behave like the members of one family?Post published in: Opinions & Analysis