Re: Parasites and paleoanthropology
Paul Crowley (Paul@crowleyp.demon.co.uk)
Fri, 19 Jul 96 21:43:13 GMT
In article <4sohbh$oak@lyra.csx.cam.ac.uk>
nmm1@cus.cam.ac.uk "Nick Maclaren" writes:
> .. a survey of human parasites ALONE would not prove anything,
This is not true. Let's say it was proved that the human flea
(assuming it is definitely specific to humans) split off from
its nearest relative at, say, 2 mya; we'd have good evidence
that hominids had fixed home bases by that time. Let's say
it was proved that the Guinea worm (dracunculus) speciated at
1 mya; we'd have good evidence that before that time hominid
populations were in permanent residence around the types of
water holes inhabited by certain species of water snails and
that they had achieved a certain level of population density.
This information could point to a definite type of habitat and
indicate probable diets.
In fact EACH parasite could give us good information on hominid
ecologies and population densities.
> but comparing the number of our parasites that have a water-borne
> stage with other animals from the savannah and lakesides might.
Such comparisons would, undoubtedly, be very useful. But it would
be more for avoiding mistakes. There are problems, of course, with
our closest relatives, such as chimps. They can catch human
parasites that would almost certainly have not proliferated in a
natural chimp environment. Measles, for example, requires a
minimum population of about 500,000 and could not have existed
before cities. That a chimp has measles, or polio, or a liver
fluke, or even dracunculus, might only indicate that it had some
direct or indirect contact with humans. In each case the full
ecology and evolution of the parasite (and its other hosts) needs
to be investigated and objective conclusions derived. One
preconception that would need to be removed from the investigators'
heads is that prior to about 10 kya h.s.s and its ancestors went
around in nomadic bands of about 50.
Paul.
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