October 28, 2005

DO WE ALL TRACE BACK TO ONE GUY?

I saw a documentary on the National Geographics Channel a few days ago "DNA MYSTERY: A SEARCH FOR ADAM." It was extremely interesting and, sort of disturbing in an enlightening type of way.
Basically the premise is that all "men" have a common ancestor who lived in South East Africa around 60,000 years ago. This was formulated by DNA testing, and apparently all "men" have a common gene that goes back to this one dude. I'm not a DNA expert at all, but it has something to do with our Y chromosone.
The guy who came up with this theory isn't denying evolution, as he knows other men coexisted with this "Adam" guy. He does believe that for some reason, the other guys lines were killed off in time unless their descendants crossed with an "Adam" descendant. He thinks that Adam was the first modern day thinker and had lots of kids, and Adams line became predominant.
The variation in the Y chromosone isn't found in man over approximately 60,000 years old. Interestingly, he traces modern female genes to a "female" who lived around 150,000 years ago, which means that "Adam" and his line didn't have to be so incestuous necessarily.
I'm thinking that the dates are probably correct, but I don't get why it had to be a gene change in one guy at one time. Again, I don't pretend to understand all this stuff. I was always under the premise that when an evolutionary change occurs within a species, it doesn't just happen to one individual but most individuals in a specific region. But I can also see how it might just be one man: it is possible.
It brings up interesting thoughts though. What happened to the other guys lines who coexisted at that time? Sure, they had children who had children, but in order for their line to survive, one of the women in their lineage had to have children crossed with a guy from "Adams" lineage eventually. Those who didn't cross are now extinct, because all men alive today has "Adams" common chromosone, which leads me to believe that according to this theory, that a disease may have wiped out everyone without "Adama" Y chromosone, or maybe a few series of diseases over time.
Heck, I still believe that it was a species change around 60,000 years ago. Maybe I'll learn more about it and change my mind. Unlike some people who have their head in the sand, I am open to changing my viewpoint based on new information.

2 comments:

  1. I beleive the current modification to evolutionary theory is called punctuated equilibrium.

    A mutation causes an advantage in one gene line from that originator and it provides enough advantage that that group of descendants takes over the niche.

    http://en.wikipedia.org/wiki/Punctuated_equilibrium

    Wikipedia is your friend.....

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  2. One day in the distant future man will have no appendix. I would just think that it would happen to the masses as opposed to just one guy.

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