On Sun, 6 Sep 1998, Ray Audette wrote:

> As for breeding to consume less meat, domestic dogs have been eating a
> largly vegetable diet for many more generations than any humans and any
> dog will still do better on a wolf diet just as any human will do better
> on a Neanderthal(a non domesticated Hominid) diet.  Modern humans and
> dogs are almost identical in their degree of DNA differences when
> compared to wolves and Neanderthals respectively.

This just won't do.  It's not about what dogs, or humans have
been eating.  It's about how what they've been eating creates
selection pressure for adaptation.  Domestic dogs have been
subjected to the artificial selection pressures of human
breeders; humans have been subjected to the natural selection
pressures of environment.  Some populations of humans have been
subjected to pressure to adapt to an all-meat (or nearly so)
diet.  Some populations have not been subjected to this pressure
or have been subjected to pressure to adapt to a different kind
of diet.

There is no single non-domesticated hominid diet.  It doesn't
exist.  There is no reason to believe that all humans are
optimally adapted to a diet that doesn't exist.  There is
probably good reason to believe that all humans are optimally
adapted to some diet or other on the paleolithic spectrum.

And I think you know that degree of DNA difference is an utterly
irrelevant metric for discussing divergent adaptation on this
small scale.  If adaptation is not involved, how do you explain
the following observations of Eaton's?

        Recently-studied hunter-gatherers have serum total
        cholesterol levels averaging 125 mg/dl (Eaton, 1988), a
        value within the range for free-living non-human primates
        (Eaton, 1992).  Human societies with similar average
        serum total cholesterol levels have vanishingly low
        prevalences of CHD.  Americans and other affluent
        Westerners, conversely, have average total serum
        cholesterol values exceeding 200 mg/dl - well outside the
        "natural" primate range - and, for these populations, CHD
        is the single leading cause of mortality.

Some of these recently studied HGs would be on a diet at or near
the all-meat end of the spectrum.  But Stefansson's cholesterol
was over 200, and Andersen's was about 400 while on that diet.
Why didn't their blood lipids return to the HG/primate norm, if
an all-meat diet is ideal for all HGs and primates?  Two possible
explanations are possible:  Either the Stefansson/Andersen diet
was significantly different from the typical HG/primate diet,
causing the difference in cholesterol, or Stefansson and Andersen
were themselves sufficiently different from the typical HG and
primate to experience this different outcome.  Or both, of
course.

Todd Moody
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