Re: Evolution of human diet
pete (VINCENT@REG.TRIUMF.CA)
22 Nov 1995 21:17:48 GMT
Ward Nicholson (wardnik@southwind.net) sez:
[a whole lot about evolution and diet]
Wow, this is a huge topic. I'll just touch on a few points. Other more
knowledgeable folk can address some of the others, and correct me
if necessary.
first, I guess it should be said there are no certain answers. Overall
body shape, structure and wear patterns of teeth, comparisons with
modern creatures, and evidence of the contemporary flora and fauna
give us a basis to project the likely diet of our ancestors, but
ultimately, diet doesn't fossilize (pace the occasional cuprolith),
so there is an irreducible level of uncertainty.
`circa 7,000,000 B.P. - Meat begins to account for greater importantance in
`the human line as it diverges from the last common ancestor with modern
`ape family.
It is possible that we branched off from the pongid line a considerable
time before meat became more significant in our diet. Recent evidence
suggests that we were bipedal while still in a forest environment,
just prior to 4Mya, but it may be that meat didn't figure largely
until we moved out into the savannah and started scavenging large
predator kills, possibly as late as 3Mya.
`1,700,000 to 400,000 B.P. - Homo erectus' hunting activity increases over
`homo habilis so that meat assumes greater importance in the diet. (How
`much importance never seems to be specified.) First in human line to
`control and use fire (POSSIBLY FOR COOKING? This is my own question never
`seemingly broached in the anthropological literature looking at this time
`period). Date for discovery/control of fire seems exceedingly vague, with
`estimates going back as far as 1.4 million years ago, but maybe only as
`recently as 500,000 years ago.
`1,000,000 B.P. - Spread of homo erectus to colder Asian/European climates
`and more probable beginnings of use of fire/heat for cooking and
`processing foods (as best I can tell "reading between the lines.")
Recent findings put H. erectus in asia as early as it is found in africa.
`35,000 to 15,000-10,000 B.P. Cro-Magnons perfect big-game hunting and meat
`temporarily assumes great importance in the diet, perhaps up to as much
`50% of total food consumption during this time period.
The fact that big game held a great significance in Cro-Magnon culture
does not necessarily translate to a larger percentage of meat in the
diet. Contemporary Americans make a big deal about eating turkey
at major celebrations, and the animal figures largely in celebratory
art, but the actual feasts represent only two days in a year.
`12,000 to 10,000 B.P. Advent of agriculture coincides with rapidly
`increasing human population. Infectious disease rates rise dramatically
`beyond those prior to agriculture. (Big question: Is this/could this be a
`result of the shift in diet to agriculturally domesticated and processed
`foodstuffs as opposed to eating more wild foods? The usual investigations
`seem to look primarily at population concentrations inducing higher
`communicability of disease while ignoring the role of changing foodstuffs
`the species did not evolve on lowering resistance to infectious
`organisms.)
There is some evidence that overall nutrition declined during the
early millenia of the agricultural era, as people lost the benefits
of a diverse hunter-gatherer diet.
--
==========================================================================
vincent@triumf.ca <== faster % Pete Vincent
vincent@freenet.vancouver.bc.ca % Disclaimer: all I know I
% learned from reading Usenet.
|