A question about Adam & Eve concerning genetics.

[albengineer]

I am not good at biology and genetics so I need your help about something I've read.

In the article it is said that using the genetic code information and the mithocondrial DNA, which i specific for females and males, it is concluded that the first female (EVE) has lived 143.000 years ago in Africa and the first male (ADAM) has lived 59.000 years ago in Africa too.

According to this article it is said that Eve's husband was somebody else, which had some other genetic code and the resulting genetic code we have today is some kind of mix.

If you have some explanation (or links) about how this is concluded and how scientists look at this hypothesis it would be very kind of you if you post it here.

Thank you in advance!

 

[gerben]

I do not know what exactly it is that you want to ask. Perhaps you can tell us what article you are talking about?

I expect the article is concerned with mitochondrial DNA and y-chromosomes. Female ancestry can be traced via mitochrondrial DNA, because you exclusively inherit this from you mother. For males, male ancestry can be traced via the y-chromosome since males only get this from their fathers (females do not have an y-chromosome).

 

[gerben]

I guess that what might seem to be a problem is that the common female ancestor is not from the same time as the common male ancestor. This seems to be a paradox, only because of the inconsistent terminology that is used.

The (apparent) problem arises from the fact that we can determine the common female ancestor of us all while we can only determine the common male ancestor of the males (although this is often called the common male ancestor, it is only the common male ancestor of the current males). This explains why the ”common male ancestor” should be younger that the common female ancestor.
The following should clarify:

The common male ancestor, let’s call him Alex, has mated with some female, let’s call her Amber, which in due time gave rise to all current males. This does not entail that their descendants will all have Amber as their common female ancestor (i.e. Amber is not the common female ancestor). This is the case because the female descendants of other humans that lived at the time of Alex and Amber will mate with the male descendants of Alex and Amber, which will produce offspring with female ancestry other than Amber. Obviously this will happen many times, so that their (i.e. our) common female ancestor will go further back than the generation of Alex and Amber.

 

[albengineer]

The article

The article is this:

Adam and Eve Probably Never Met

In an international collaborative effort, Peter Underhill of Stanford University and colleagues have carried out a study of human Y-chromosome variation, by far the most comprehensive and informative ever conducted (Nature Genetics, 01 Nov 2000). Whereas it confirms the 'out-of-Africa' origin of modern humans, it suggests that our most recent common paternal ancestor ('Y-chromosome Adam') would have been about 84,000 years younger than our maternal one ('Mitochondrial Eve'). This suggests that our genetic blueprint evolved as a mosaic in which the modern pieces (of DNA) could have appeared at different times and spread within our population, each with its own pace. The study also suggests that natural selection might have put a specific pressure on the Y chromosome, and may increase understanding of male infertility in our times.

It can be found in this link: http://hum-molgen.org/NewsGen/11-2000/msg09.html

 

[gerben]

Well, that is a comparison of the findings described in a paper of Underhill, Shen, Lin, et al. (Nature Genetics 2000(26) 358-361) with other findings that are not referenced, by Trevor M. D'Souza.

The referenced Nature Genetics paper compares Y-chromosomes, and is thus concerned with male lineage. D'Souza compares this with with female lineage. I think I have answered D'Souza's major question, "How could Adam and Eve have ever begotten us if they never met?”, in my previous post.

 

[albengineer]

gerben,

Thank you for your answers. :)