Friday, October 16, 2009

A nice question


In a function / or a party occasionally, a familiar face walks to you and asks the question : "Do you remember who I am ? ".
You might reply "No".
(S)he might reply " I am your (fa/mo)ther's blah blah ..."

This is a very common situation, right ?

Now here is a very interesting study(at least I found this interesting) about relations which might startle that "familiar face" referred above :

Consider all the living females on this planet. They all have descended from a single female who lived about 1.25 million years ago. This female is called the mitochondrial eve. This is proved , because the mitochondrial gene passes on only from mother to daughter (not sons).

So mathematically :

Let x be an element belonging to F, the set of all females who are living today.
Then for all x, M(M(M(.........M(x)))))) = will lead to Mitochondrial Eve. M(x) is defined as Mother of x.

Now my questions to the reader who has kept his attention until this point:-
a) Was there a single Adam and Eve pair when this Mitochondrial Eve lived ?
b) Was she the only female living then ?

Update with Answer :-

Here is a graph which is showing the Mito eve of the 4th generation tracing back to the 1st generation.

2 comments:

richie said...

b) The same mutation can happen at two different places at a similar time(unlikely, but possible), and hence, there could be multiple females. That would also imply that there could have been mitochondrial eves?

sudeep said...

Answer is right,(there were multiple females). But the explanation is as follows :-

Assume there are 4 females at the time of Mitochondrial Eve. At some point of time, for three females, the female line got terminated. Means, their descendants' descendants became only sons and no daughters. Hence the mitochondrial gene was lost. Whereas for one female, the female line has continued till date. She becomes the Mitochondrial Eve.