Re: Dating with DNA? Problems and Current Approaches

prd wrote:

I have actually done this. Dating something like Oetzi is particularly
problematic and I do have to bring in an eastern example. Ad*** et al did a sequence of LM3 and claimed it was as divergent from humans as Neandertals. I looked at the sequence and there appears to be examples
of cytosine deamination. The core eastern/east african mtDNA sequence is present in LM3 sequence but many other substitutions are present.

In general mtDNA, particularly HVR1 cannot be used to date migrations
unless a very large sampling is done.

Dating with mtDNA has been flakey from the beginning. The first time it was published it did nothing more than assume a rate of mutation. Immediatedly a paper was published showing a much higher rate. I never came across a definitive resolution just more claims using the original, low rate assumption.
....
For example. 24,000 years/24 years per generation = 1000 generations so that
0.001 mutation is expected per generation. So let us say you had
1,000,000 people all with the same original mtDNA you could
assess the age by looking at the number of mutations.

And here is one example. A genetic generation is birth to birth. A girl is born, 14 years later hits puberty and 9 months after that gives birth to a girl. Repeat. Gives birth to a boy? The 15 yo boys to marry/impregnate (depending upon the civilization level) the 14 yo girls have to come from some place.

15 maybe 16 not 24 years per generation. We so commonly use the word generation but there are several different lengths for it depending upon the context in which it is used.

IOW with your assumption I just got you 1500 generations instead of 1000. That is a significant difference. Each child from the same mother would have the same chance of a DNA mutation to there is no point in averaging the child-bearing years.

--
Prevent the end of the world. Destroy Israel today.
-- The Iron Webmaster, 3681
nizkor http://www.giwersworld.org/nizkook/nizkook.phtml
Iraqi democracy http://www.giwersworld.org/911/armless.phtml a3
.