Re: "Where is Noah?" Then and now.
Posted: Sun Jun 19, 2011 10:30 pm
O, we have been over this before Leg
http://en.wikipedia.org/wiki/Mitochondrial_Eve
Common fallacies
see below fromFurther, there is the genetic evidence. If we track that genetic information of the female line, we should be able to track it all the way back to Eve, and so we do, we call her mitochondrial Eve. However, if we track the male line, there was not one, but two seperate times in history when there was one single male ancester of all men. The first was Adam, and the second was Noah, the ancestor of all 3 other men living, although their wives were daughters of three seperate women. As such, the male line genetic information for Adam would have been overwritten by that of Noah, and thus the date of this falsly named Y-chromasonal Adam (actually Noah) would read as considerably later than Eve. This is axactly what we do read.
http://en.wikipedia.org/wiki/Mitochondrial_Eve
Common fallacies
Not the only woman
One of the misconceptions of mitochondrial Eve is that since all women alive today descended in a direct unbroken female line from her that she was the only woman alive at the time.[10][11] However nuclear DNA studies indicate that the size of the ancient human population never dropped below some tens of thousands;[10] there were many other women around at Eve's time with descendants alive today, but somewhere in all their lines of descent to present day people there is at least one male (and men do not pass on their mothers' mitochondrial DNA to their children, so the mitochondrial inheritance chain is broken). By contrast, Eve's lines of descent to each person alive today includes precisely one line of descent to each person which is purely matrilineal.
Not a contemporary of "Adam"
Sometimes mitochondrial Eve is assumed to have lived at the same time as Y-chromosomal Adam, perhaps even meeting and mating with him. Like mitochondrial "Eve", Y-chromosomal "Adam" probably lived in Africa; however, this "Eve" lived much earlier than this "Adam" – perhaps some 50,000 to 80,000 years earlier.[12]
Not the most recent ancestor shared by all humans
Mitochondrial Eve is the most recent common matrilineal ancestor, not the most recent common ancestor (MRCA). Since the mtDNA is inherited maternally and recombination is either rare or absent, it is relatively easy to track the ancestry of the lineages back to a MRCA; however this MRCA is valid only when discussing mitochondrial DNA. An approximate sequence from newest to oldest can list various important points in the ancestry of modern human populations:
The Human MRCA. All humans alive today share a surprisingly recent common ancestor, perhaps even within the last 5,000 years, even for people born on different continents.[13]
The Identical ancestors point. Just a few thousand years before the most recent single ancestor shared by all living humans comes the time at which all humans who were alive either left no descendants or are common ancestors to all humans alive today. In other words, from this point back in time "each present-day human has exactly the same set of genealogical ancestors". This is far more recent than Mitochondrial Eve.[13]
"Y-Chromosomal Adam", the most recent male-line common ancestor of all living men, was much more recent than Mitochondrial Eve, but is also likely to have been long before the Identical ancestors point.
Mitochondrial Eve, the most recent female-line common ancestor of all living people.