On Wed, 19 May 1999, Bernard Lischer wrote:

> My use of the term "energy intake" is intended in a quantitative sense, so
> perhaps it is too specific.  In any case (including where foreign proteins
> are concerned) I think that quantity is anything but irrelevant.  The higher
> the yearly intake, the greater the selective pressure.

Perhaps the key here is the more *occasions* of exposure to the
protein per year, the greater the selection pressure.  But note
that this also counts against, say, apples, which are only
available in the wild for a few weeks in the fall.

> Optimal foraging theory pretty much rules out the use of things like grains
> in all but the leanest of times.  In other words, the energy spent gathering
> them delivers less of a return than an equal amount of energy spent
> gathering or hunting other food sources.

I think the theory is too simplistic in that it ignores the
division of labor possible in a simple human society.  Children
who are too young to hunt, for example, can gather seeds and
grains.  During the brief period when grains can be harvested, it
is not such a chore.  If I think of it I'll try to dig up the
post on the Paleodiet list where the caloric yield for
hand-gathered ripe grain was calculated.  If I remember right,
the yield in dry weight was on the order of kilograms per hour,
which isn't bad.

> So unless more profitable food
> sources run short, grains are ignored.  My understanding is that a wide
> variety of easily attained foods were available to paleolithic peoples
> during the months of the year when grains are mature.

Gathering grains is easy enough before they fall to the ground.
I see no reason to believe that they would be ignored, but I can
accept that exposure to them was minor in the yearly scheme of
things.

Todd Moody
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