The majority of mutations result in killing the organism, or
rendering the organism incapable of reproducing. This is a safety mechanism, and
it's ignored
or glossed-over by scientists, because mutations are accepted as
the primary cause of Evolution.
This is not quite true, according
to reports I've seen from (a) geneticists and (b) medical researchers.
The
geneticists report that each human genotype carries about 100 mutations with
respect to its parents' genotypes. I don't know the error bars on this number,
and it's too late tonight to try to find them. Nor do I have data for other
species, whether animal, vegetable, or otherwise.
Medical researchers report
that somewhere between 35% and 50% of human fœti fail to produce a
living baby human. (The 35 and 50 seem to approximate the error bars, here.)
This effect includes, it seems, everything from implantation failure through
observable spontaneous abortion to full-term stillbirth (like one of my older
sisters). It does not seem to include first-week-of-life deaths in hospital
(like my other older sister and my youngest brother).
I don't have figures
for infertility, much less broken down by genetic-caused vs other-caused,
but we can observe that total infertility is not a majority issue. The figures
I find lump transient and permanent infertility together, and don't separate
endogenous vs exogenous causes. The range from 3% to 14%. Many
mutations are known that do not impair fertility.
Putting these figures
together in the middle of the night indicates that, even assuming, without
evidence, that mutation is the sole source of fœtal failure, the
probability of failure in H. sap sap caused by mutation is between .35%
and .5%, two orders of magnitude less than "a majority." Most other species
have genomes that are even less prone to terminal mutations. ---
--Bill.
NAL: question the answers, especially mine. [ Reply to This | Parent | # ]
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