Re: Mr. K and Mr. S... was: Death of a hypothesis

13 Aug 1996 12:40:19 GMT

Elaine Morgan ( wrote:
: In article <> wrote...

: > Paul Crowley <> wrote:
: >
: > >The aspect that I find hard to cope with is the sheer quantity of
: > >water that the sweating mechanism requires. The early hominids
: > >must have lived right beside fresh water streams or springs.
: > >And given the heat stress that we all agree they were subject to, this
: > >can't have been in a forest. It means that their habitat must have
: > >been extremely limited.

: Flooded forest maybe? Gallery forest?

: The trouble I have in imagining this mosaic (apart from the fact that if
: they were all living in it it wouldn't account for the himinds shooting
: off in an entirely different direction) is: Since the climate over this
: mosaic would not presumably have varied much from one spot to another,
: why would some patches have trees and others only grass? It could have
: been accounted for by mountains but I am not aware that mountain areas
: are included in the imagined habtitat. The difference would surewly
: have to be in ground water, standing water, flowing water, lakesides
: etc. The forested bits would be the wetter bits. Some parts could well
: have been at least seasonally flooded, like the bonobo habitat.

Harry Erwin here.

Lake Victoria (I don't know what the new name is, BTW) creates just such a
climatic mosaic. Within a few miles of the lake, the climate is very humid
with areas of rain forest, while further away, you get savannah,
semidesert, and desert. You also have major highlands in the area, which
create rain shadows. This has been going on in that area since the late

The existence of such climatic variability (patchiness) in the area is
just the precondition needed for high variability in the characteristics
of local populations, particularly if prior to H. erectus there wasn't
much hominid tolerance of niche variability. Behaviorally-based speciation
would have been rapid, chaotic, and unobservable in the fossil record.

Harry Erwin, Internet:, Web Page:
49 year old PhD student in computational neuroscience ("how bats do it" 8)
and lecturer for CS 211 (data structures and advanced C++)