Most Recent Common Ancestor Only 3,500 Years Old?

[Falloutdude]

I've been thinking and talking about this with a few other members. It's essentially sparked by an article in Nature, a reputable scientific Journal which regularly writes articles about and on evolution. So it's not fueled by creationists. Also the data was gathered based on data about people on the last 20,000 years, implying the people who did it (from MIT and Yale) weren't driven by a creationist agenda/is secular.

 

http://www.nature.co...ature02842.html

 

I'm just wondering if anyone can explain this to me/understands this, how can turn out such a recent date? especially when there's evidence people in Australia and the Americas being isolated well before this (50,000 and 10,000 years respectively. Not just this, but their projected "Identical Ancestor's Point", where all ancestors are identical, is only 5,000-15,000 years BP (In 2002).

 

The model made it into Nature in 2004 (Unfortunately a subscription is needed to read the whole thing, I got the full article through my college's online database, but it prohibits posting to sites.) Basically it's saying the complex computer simulation came up with that even the most conservative and liberal "assumptions" about migration and reproduction that our most recent common ancestor is around 5,000 to 2,000 years BP. This of course doesn't seem to make any sense based on our knowledge of evolution and anthropology. However it is obvious from the extensive citation on the second link (describing the process in more detail), they extensively accessed the anthropological record of the time while constructing this model/ computer simulation (which has less accurate theoretical precedents it has built on about common ancestry)

 

http://tedlab.mit.ed...de-MRCA-two.pdf

 

Here is my explanation of the "MRCA" Portion, at least that i've thought of.

 

"But after so many generations the genetic influence is inconsequential, that is, it cannot be traced. Plus i don't think this is meant to disprove evolution, or even that it implies that it does. I think it's just saying that he has a "genetic hand" in everyone's DNA who are alive today. That is, even if minimal, everyone who is alive today has some genes from this guy or girl. Not that we all came from him. I think i read it's not saying that everyone came from him, rather that even with very little migration a settler's offspring would contribute to the entire local population by a certain amount of years."

[Sexton Blake]

If a common ancestor of all living humans is defined as an individual who is a genealogical ancestor of all present-day people, the most recent common ancestor (MRCA) for a randomly mating population would have lived in the very recent past

 

 

you are looking at an ancestor of all MODERN people, all the modern types of people (with all the latest divisions) and not the ancestor of just "people" as in:

 

 

http://news.discovery.com/history/ardi-human-ancestor.html

 

 

From 4.4 million years ago.