This is expanding upon a previous post. Geneology itself poses an interesting topic. Everyone has two parents and then four grandparents and then eight great-grandparents and this grows two-fold. Of course there will be some repeats. But eventually the number of ancestors reaches a number larger than the world populations. This brings into mind that two seemingly different people are possibly related to each other. A more recent study shows the most recent common ancestor of all humans to be more recent than previously thought. Some point to as recently as 3,000 years past.Of course the Most Recent Common Ancestor is an elusive person. It is unknown where he or she lived and in what era or conditions. Of course there can be more than one of them. More likely than not, he is a statistical construct and scientists can only conjecture an idea of who he is.

While many can argue the geographic and social barriers, a small amount of crossing over these barriers usually led to more relationships between different groups. These barriers have been incorporated into models that have been run through computer simulations. From there it is deduced that the most recent common ancestor is more common than believed.

There are some who speculate that within 2000 years that everyone will be descended from most of us living today. An important exampe of this is mitochondrial Eve the common female ancestor of all humans. Maternal descent is specified through the mitochondria as the mitochondrial genes are always maternally inherited. Likewise in males, the Y chromosome is paternally inherited only. A possible candidate has been implied who lived around 200,000 years ago.

This study has been corroborated and further studied with DNA evidence of allelic changes in different genes.

This can be summarized by this flash presentation at this link: http://www.pbs.org/wgbh/nova/neanderthals/mtdna.html#

Cited

http://itotd.com/articles/226/most-recent-common-ancestors/

http://www.eurekalert.org/pub_releases/2004-09/yu-rc092904.php

http://www.moonzstuff.com/dna/mrca.html

http://www.pbs.org/wgbh/nova/neanderthals/mtdna.html