Re: Morgab tears /salt

Thomas Clarke (
16 Nov 1995 13:23:51 GMT

In article <48biup$> Alex Duncan
<> writes:

In reaction to Elaine Morgan pointing out a difference in composition
between ape and human tears (which as is her wont she attributes
to an aquatic phase) Alex replied:

> Let's think this though in the simplest possible manner....
> what do humans do differently than chimps that might make us more
> susceptible to this kind of thing? The most obvious one that jumps to
> mind is that the majority of humans live in incredibly dense population
> clusters in comparison to all other primates. ... and it could
> be argued that conditions for epidemic spread of diseases have been
> present at least since Neandertal times (cave dwelling). Thus, the
> simplest explanation for differences between the content of tears in
> humans and chimps is that there has been selection in humans for
> individuals who are capable of withstanding the viral/bacterial onslaught
> that occurs in dense population clusters.

Thus you prefer an explanation which invokes conditions that only
obtained in the past 10,000 years or less, or with a bit of hand
waving in the past half a million.

I don't think anyone has yet commented on my suggestion that there
is a tendency among PAist to favor explanations for ape/human
differences that place the changes as late as possible.
I think you reaction to the stipulated tear composition problem
illustrates this. Putting aside the AAT explanation, explanations
could be thought up based on exposure of the eyes to windblown dust
on the savannah etc that would place the change much further back in time.

The impulse seems to be to go for the recent explanation.
Curious in a metascientific way..

Tom Clarke