Professor Sykes discusses our common ancestors

Student:
Wouldn't that African woman need to be fertilised by some African man, or something? And, are you able to trace our existence to people, like that far back, like the first ever people?

Professor Sykes:
I'm only talking about the research which I've done with this particular M-DNA which is going through the maternal line.

With many, many other ancestors whose DNA's come down in different ways, like for example, a father's line which we can talk about with the y chromosome but many other ancestors, like our father's mother, father's mother, so and so, and so forth, that we're not tracing, but it will still follow the same rules. And of course the woman that we're talking about who lived in Africa, let's say 150 thousand years ago, of course she would have had to have children with the help of a man.

But it's also the case that she certainly wasn't the only woman around, and there were many others around, but their maternal descendants are not alive today so many other women who would have had daughters so you could have passed their M-DNA on. Eventually those lines petered out - either the women didn't have any children at all or if she only had some, so there's only relatively few people, a few women, and ultimately only one whose maternal descendants are alive today.

We do have a common male ancestor who's given us our y chromosomes but he didn't live quite so long ago. And other genes that we have, say blood genes and all these things, will have common ancestors who lived at different times. So we all have, I mean all our genes and all our chromosomes, they're an amazing mixture of loads and loads of different ancestors but the ones that we can really study well, because the inheritance are very simple, only coming through one parent, is the M-DNA and the y chromosome on the male side.