On 11/21/2015 04:05 PM, Don wrote:
> I hear a warning buzzer when I hear them say DNA proves someone
> "descended" from some group identified as existing 6000 years ago.
> Evidently they are using just one "marker" to make the link, when
> there must be a mathematically impossible number descending from all
> the mix of DNA pairings. Don't say when the DNA tied in. No
> information about what happens when individuals with widely different
> DNAs reproduce. What are the rules that govern when DNA get to
> evolve/mutate? I want more Darwin's Rules in on this.
mtDNA is non-Mendelian. The mt is 'mitochondrial' not 'maternal'. The
confusion arises since mtDNA is solely inherited from the mother in
humans. Paternal mitochondria get killed off after fertilization. The
mitochondria are also relatively simple with only 37 genes. That makes
them very handy for tracing population flows through mtDNA mutations.
The Jews had it right; it's the mother that determines if you're a
biological Jew or not. Ironically, for the Ashkenazim there appears to
have been a bottleneck, with a very limited number of founding mothers
who seem to have been converts. In other words, for most Ashkenazim by
their own rules -- not.
The Y-DNA, which is only present in males and is the paternal descent
does show more middle eastern influence but that doesn't count. Think
about that for a moment if you are a male. You have one X and one Y
chromosome. Your mother had two X chromosomes. Very little of your Y
chromosome differs from your father's since your mother didn't have one
to combine with it.
Then there are the other 22 chromosomes where all the wife swapping goes
on. Those are called the autosomal chromosomes. If you round up your
close family there will be similarities. Further back it gets really
cloudy. 23andMe, FamilyDNA, and the other companies do test them and
give you some rough idea of your ancestry based on comparisons to native
populations.
For example, 23and Me has three different graphics, Conservative,
Standard, and Speculative. For Conservative, I'm 97.8% European and 2.2%
Unassigned. For Standard, I'm 99.8% European and 0.2 % Unassigned, up to
99.9% for Speculative. The only real difference is they do more guessing
about what is Broadly Northwestern European and Broadly European all of
which can be taken with a grain of salt.
I'm pretty boring and probably won't be eligible for any affirmative
action programs but some people are more colorful.