Re: Questions about human aquatic past
- From: VtSkier <vtskier@xxxxxxxxxxxxx>
- Date: Sat, 27 Jun 2009 01:42:10 -0400
Oops! Sorry Ross, I listed your name below
without looking first and got is wrong. My
apology.
VtSkier wrote:
Algis Kuliukas wrote:.On Jun 26, 8:04 am, VtSkier <vtsk...@xxxxxxxxxxxxx> wrote:So I posted, in reply to another thread,
what I understand about the possible semi-
aquatic past period in human development.
I got zero, zip, nada, in response. Are you
guys going to continue to fight with each
other or would you like to try to educate me?
Sorry. You deserved a better response. If I'd have seen the posting
I'd have responded anyway. Better late than never...
So, one of the arguments for Human 'specialness'
and perhaps other characteristics is the
possibility that some ancestor(s) spent enough time
in a shore or semi-aquatic environment for some
'adaptations' to occur and stick with us.
That's right. The key observation here is that although human beings
are the chimpanzee's closest relative (not by much mind, and the error
bars are high enough to suggest that it might still be the gorilla)
there is no doubt that we are the odd man out of the four great apes.
The 'odd' features are not distributed evenly. It's not like we talk,
chimps walk and gorillas are naked. We got all three - and about
thirty others besides, whilst they've have none of them.
So, the usual Darwinian response is to ask why? What could have
happenned to us to make us so remarkably different?
Now, for donkey's years (long before Dart even) the orthodox paradigm
has been what might be labelled "the savannah theory". Elaine Morgan
did label it that. No-one had bothered before because they were so
sure it was right, in the same way that no-one ever coined a term like
'The God Theory' before Darwin.
The trouble is if you look for convergences - the thing evolutionary
biologists should do - between humans ans savannah mammals you don't
find any. Well very few in any case. Hairlessness, being fat, big
brained, k-selected infants etc are not associated with savannah
mammals but they are associated with some aquatic mammals. So, the
question is could there have been some additional selection from
moving through water that could have influenced our phenotpye in this
way? Some of us thin the answer is a clear, definite YES!!!
Most authorities, however, have been too busy rolling their eyes or
turning a blind eye to the idea that, in 50 years since Hardy first
came out on the idea there has been just one decent attempt to
critique the idea published in a 'proper' anthropological journal -
John Langdon's 1997 paper in JHE. Unfortunately, what he did - and
what most aquasceptics do - is exaggerate the idea to breaking point.
They really never get beyond the label. They ask: Was there even an
aquatic ape? Even I would answer 'no' to that.
The other key point that people usually misunderstand (I suspect
willfully) is that "it" is not one idea but several. That's why I like
to call THEM waterside hypotheses (plural) of human evolution. Hardy/
Morgan originally postulated a kind of 'semi-aquatic' phase - in the
sense that humans were 'on their way' to becoming a fully aquatic
mammal, and then there was this U-turn. Verhagen et al propose that
our great ape ancestors were already somewhat aquatic - what they call
'aquarboreal' (wading-climbing) - and that early Homo evolved on the
coasts and became pretty well adapted to swimming and diving. To them,
australopithecines are nothing to do with our evolution and H sapiens
kind of reverted to being terrestrial in another kind of U-turn. There
are other views too and clearly they differ gretly in timescale etc.
My own model is called "River Apes... Coastal People" which I think is
self explanatory. (I have a web site - unfortuantely a little out of
date and crappy but some of it is good) where you can read more about
it at www.RiverApes.com but basically I think our ancestors have
pretty much always lived by the water's edge - so no U-turns. Our
'aquatic adaptation' I think peaked at the time of the H sapiens
speciation event at around 300Ka - 500Ka. I think my view differs from
most because it appreciates, more than the others, just how LITTLE
selection is needed to make a profound effect on phenotype. I accept
humans are 100% (to the nearest integer) terrestrial today and
probably have been for 2.6Ma, BUT if we did ANY appreciable amounts of
wading, swimming and diving since then it would EASILY account for the
otherwise bizarre phenotypic differences we are trying to explain.
Maybe, maybe not. But some of the arguments
for human 'specialness' among primates just
don't hold water (so to speak):http://www.impactlab.com/2008/03/26/swimming-monkeys/
I've know about swimming macaques for a very long time.
These monkeys, in addition to swimming, dive, swim
under water, feed on aquatic life and additionally
have a little fun in the water.
Oh, yeah. In order to find food under water as the
video clip shows, they must keep their eyes open.
You cannot doubt that humans are the odd man out of the apes. We are
naked, they are not. Our babies are fat, their's are not. We can
speak, they cannot. We swim and dive far better than they do. We have
far bigger brains than they have. Our infants are more k-selected than
their's are.
Stephen Oppenheimer, in his Journey of Mankind,
posits a shoreline hugging migration route for early
modern humans as they populated the world. While
the seaside habitat would afford good support for
the migrating population, I think the time line is
too recent for some of the benefits purported
for this lifestyle to have made much of an impact
on physical adaptations.
If the semi-aquatic lifestyle had any effect, it
had to have happened, oh, say 2 million years ago
or so.
Well this is where you would agree with Marc et al. That's what they
think. My view is that even a coastal migration out of Africa (if it
was a universal that every human ancestor went through) would be
sufficient. I don't actually think it is quite sufficient though,
because clearly many modern human African populations never had such a
coastal migration like that, which is why I propose that the H sapiens
speciation itself happenned on the coasts and that the genus Homo have
basically been living there (and in other waterside habitats) for at
least 2.5 Ma.
I hope this helps to give you some balance to help you to make your
own mind up about this idea.
Algis Kuliukas
Thank you for your reasonable reply. I have
previously thanked and responded to Pat Crowley
and Robert McFarland for their responses also.
In my reply to Pat Crowley I noted that my
personal interest was in discussing and learning
about what happened to (mainly) modern humans
AFTER they became what we are now and BEFORE
we started down the road to civilization.
In other words, I am looking for Anthropological
studies rather than Zoological studies. I think
the discussion of what was the 'first cause' of
the physical adaptations which we now carry fall
into the latter and that discussions of culture,
and other responses to the world about us falls
into the former. I also asked if this was the
place for such discussions. Robert kindly gave
me the names of a couple of listserves which
might suit my purposes better than here, but I
prefer the easiness and informality of newsgroups
as long as the noise to signal ratio isn't too
high.
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- From: VtSkier
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