Re: Parasites and paleoanthropology
Paul Crowley (Paul@crowleyp.demon.co.uk)
Fri, 19 Jul 96 21:35:43 GMT
In article <keith.85.000C8262@GECKO.BIOL.WITS.AC.ZA>
keith@GECKO.BIOL.WITS.AC.ZA "Keith Norris" writes:
> Paul Crowley <Paul@crowleyp.demon.co.uk> wrote:
>
> >I suggest that a thorough and wide-ranging study of h.s.s.
> >parasites (and their evolution) would show that fairly dense,
> >localised and sizeable hominid populations have inhabited areas
> >close to standing bodies of fresh water in the tropics at or near
> >sea-level for many hundreds of thousands of years. In other words,
> >such a study would go to disprove hunting/savannah theories of
> >human evolution.
>
> No it would not. The savannah theory does not mean arid, without water.
AIUI (please correct me if I'm wrong) conventional "hunting/savannah"
theories suggest that nomadic bands of about 50 hominids foraged for
meat and vegetables; and they imply low population densities. It's
very difficult to see how a parasite like the Anopheles mosquito could
have evolved to exploit such a population. Even supposing that it
did, it's much more difficult to see how four species of malaria could
have evolved to exploit both the the mosquito and the nomadic hominids.
By the time the plasmodium had multiplied within the hominid host to
enable it to propagate, the host would have moved on.
Most parasites require *resident* hosts. They spend different
stages of their lives in each host and need to transfer between
hosts when they're ready. The right species of snail has to be
in the right water-hole. It's much, much easier for the parasite
if there's a large population of hominids that uses the same water
holes for many years, if not generations.
> Early man would have needed water from some place, not so?
I'm talking of "late man" not early man. Probably the last million
years at most.
> I suspect that you are trying to propogate the AAT.
I am not. The AAT proposes a phase about 5-4mya. Parasites
should be able to tell us a lot about the last 200 Kyr. They're
most unlikely to tell us anything about hominid life >2mya.
Paul.
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