Jim Swayze wrote:

> According to Dr. Sara Johnson of Cal State Fullerton, the
> development of alcohol dehydrogenase was -- like the
> development of lactose tolerance in some -- an "adaptation to
> agriculture." 

This argument about lactase and alcohol dehydrogenase is by the way very
limited and misleading, and I would say it is sufficiently misleading to say
that Dr. Johnson is wrong or that you are misquoting her opinion. Does she
support her view with good arguments?

The comparison is misleading because lactase, the enzyme for metabolizing
lactose, has been necessary for as long as mammals have been nursing their
offspring (i.e., for 60+ million years). Tolerance to lactose in adulthood
evolved in people of European descent only because of a relatively tiny
evolutionary step to the continued production of lactase beyond infancy.

It is much less likely that we could have evolved an entirely *new* enzyme
for metabolizing alcohol at the dawn of agriculture merely because we
learned to make beer from grains, as you say is the argument of Dr. Johnson.


In fact if this Dr. Johnson is correct then the entire premise of paleodiet
theory is false: if we evolve new enzymes so quickly then humans evolve much
faster than we think and we should be quite well-adapted to most
non-paleolithic foods. 


-gts