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Re: Morgab tears /salt
Elaine Morgan (Elaine@desco.demon.co.uk)
Tue, 21 Nov 1995 13:22:15 GMT
In article: <48biup$rr1@geraldo.cc.utexas.edu> Alex Duncan
<aduncan@mail.utexas.edu> writes:
> a
>
> There's one particular point here that is unclear to me: are you
> suggesting that there are lots of viruses and bacteria present in sea
> water that are capable of infecting humans? If so, I would like to see
> some documentation, and frankly, documentation based on samples from
> modern sea water wouldn't do, because modern sea water is so
contaminated.
I am not suggesting that there are any more ( or any fewer) bacteria and
viruses in sea water than there are in the air. I am pointing out that in
land mammals the secretion of tears protects against the danger of
infection, and that the tears - even the constant small secretion of
tears to coat the eyeball - are present all the time. I am suggesting
that if you are moving through water with your eyes open this secretion
is going to be washed away, and need more constant renewing than if you
spend all your time on land.
s.
>
> Let's think this though in the simplest possible manner. We have a
> potential difference between humans and chimps (protective elements in
> tear fluid) that needs explanation. The possibility that human tears
may
> have higher concentrations of these "protective" materials suggests
that
> humans are more susceptible to infection via the eye balls than chimps.
> Well, 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. Urban living has been
> demonstrated time and again to put humans at special risk for the
> epidemic spread of contagious diseases. Urbanity has been a feature of
> human social behavior for at least several thousand years, 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.
>
> This explanation has two major advantages over the one Ms. Morgan has
> offered:
>
> 1) It is based on observed differences in the lifestyles of chimps and
> humans.
>
> 2) It doesn't require an implausible "aquatic phase" for which no good
> evidence has been found.
>
>No, but what it does require is a further proliferation of time scales
for all the different types of anomaly in human physiology. We are asked
to believe, wwithout any evidence one way or the other, that all these
unique attributes emerged serially. Bipedalism first, for a reason that
is still up for grabs, nakedness later at an unspecified time for an
unspecified reason, laryngeal descent at some other time for some even
more mysterious reason, and now the tears thing latest of all - it sounds
as if you are post-dating this to the Industrial Revolution.
>
There is no evidence that they didn't happen at the same time and for the
same reason, which would be far more parsimonious. The only reason for
rejecting this supposition is that the one thing that may logically
link them is water,
I don't think there is or can be any evidence that neanderthals lived in
conditions more conducive to the apread of disease than many other
species, especially pack animals and burrowers like rabbits or prairie
dogs. And I haven't hear that they weep.
Elaine Morgan
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