New DNA Study Helps Explain Unique Diversity Among Melanesians

Eureka Alert ^ | 2-28-2007 | Temple University - Preston Moretz

[Pharmboy]

Yes...but you said above that Cavalli Sforza had the Melanesians the farthest away from the Africans. THAT doesn't seem to make sense if they are also old--they should be closest to the originals, the Africans.

[Varda]

Genetic distance is a measure of the dissimilarity of genetic material. The more dissimilar, the further away (in time) from the point of divergence. For this to work, you have to believe that there is a constant rate of mutation that can be translated into time.

[Pharmboy]

I understand that...but it still makes NO sense that two populations considered VERY old would be VERY distant from each other.

[Sam Ketcham]

"New Guinea highlanders" I'll bet they look cute in their plaid grass skirts.

[blam]

"I was told that Africa has more genetic diversity than the rest of the world combined."

The Toba eruption 75,000 probably is responsible for killing most of the other genes outside Africa. Albeit, the Neanderthals and apparently the 'Hobbits' on Flores suevived that eruption. It was the 'nuclear-winter' effect that did the killing, btw.

[Varda]

One is the founding population and the other is maybe the first daughter population. Both populations continue evolving, accumulating mutations. Over time they become more and more different. Because of the early split, this first daughter population doesn't contain the entire catalog of mutations of the founder population. The population with the most unique mutations compared to another population is the most distant from that population.
More recent daughter populations will contain the recent mutations and will not have had enough time to accumulate many unique mutations of it's own. These populations are considered closer in genetic distance.

[Varda]

The human race seems to have had some really close calls. I think it's possible other Homo erectus populations survived too (New World maybe).

[Pharmboy]

OK--so what you're saying is that the population closest to the original differs the most from it based on mutations occurring since the fission. These suppose different mutation rates of different populations and would then throw out the biogenetic clock.

[Dustbunny]

Interesting

[To Hell With Poverty]

"I'm not physically or mentally deficient. Nor am I Muslim. But genealogy is fun for me because so many of my lines converge on common ancestors. Us Southerners had ancestors who lived in rural areas with limited access to new blood. We did ok."

LOL, maybe you should change your FReeper name to "Twig" then, as in "if your family tree doesn't fork...." ;-)

[SunkenCiv]

GGG managers are SunkenCiv, StayAt HomeMother & Ernest_at_the_Beach	join list or digest view topics view or post blog bookmark post a topic subscribe
Blast from the Past. Just updating the GGG info, not sending a general distribution. To all -- please ping me to other topics which are appropriate for the GGG list.