In article <34EBE78E.3066 at netcom.ca>,Tom Matthews <tmatth at netcom.ca> wrote:
> I will assume that you mean identical twins rather that fraternal twins
> which are merely brothers.
>> Even identical twins, however, are of at least two kinds. All share
> original nuclear DNA, but some may have different mitochondrial DNA.
It could happen, but there's only about 2000 mitochondria in a cell.
With a population of that size, an initially varied mitochondria
genepool would drift to fixation in only about 4000 cell divisions,
which is only about 100 or so human generations. Mitochondrial
mutants are much rarer than that, so the overwhelming proportion
of eggs will have every mitochondria genetically identical. So
while identical twins could get differing proportions of their mother's
mitochondrial genes, in the vast majority of circumstances all
2000 will be the same and there's nothing to vary.
I imagine there's nothing to find in the literature because nobody
thought it would be common enough to justify a study.
Curt Adams (curtadams at aol.com)
