Notes
Introduction
Morgan/Hardy
present AAT
as if "the
aquatic phase is itself taken as an established fact."
Criticizes the adaptationist program (a la Gould and Lewontin).
AAT
is a 'Just
So Story.'
"We might as well argue that the fine balance controls and
other characteristics that enable us to ride bicycles must have been
developed during a bicycle-riding phase in the Pliocene - perhaps with
tandems as reinforcing devices for ensuring monogamous coupling (although
not necessarily in transit)" p133
The Adaptationist Scenario
Gould/Lewontin - 'The adaptationist programme' AAT is a first-class example
'taken to the extreme' every traits not positively hydrophobic taken as a
product of natural selection during an aquatic phase.
Morgan "under
the flimsy pretext of examining the supposedly competing 'hypotheses'
of
neoteny and a strictly savannah origin"
The neoteny argument is a straw doll (Morgan 1982 p 22)
The savannah theory is not difficult to criticise. "Many such efforts appear
in the secondary literature, often written by people with no greater claim
to expertise in current evolutionary theory (and its major points of debate)
than familiarity with popular notions of Darwinian natural selection,
survival of the fittest and adaptation as an overall outcome" p135.
"But all such
interpretations, by synthesisers or specialists, correct in their details or
otherwise, set the hominids within a generalised woodland-savannah mosaic of
the
kind clearly
indicated for eastern Africa during the plio-pleistocene." p 135
"Savannah theory does not stand in competition with one or other rival
theories, as Morgan suggests" p136
Macro-evolutionary events happened - no doubt about that. Other mammals were
similarly affected.
On
the Beach
3 pts about Hardy/Morgan AAH: body hair/sc fat, implications of our apparent
aquatic adaptations and significance of fossil evidence.
1. Body hair.
'Hair loss for faster swimming. "The evidence is merely a claim by Hardy
(1977) that members of the Sydney University
swimming
team shaved one
second in a hundred-yard swim
by
shaving off all their body hair" p 136.
2. Human aquatic adaptations - like diving reflex are criticised.
'Human 'adaptations' to aquatic life are, by comparison (to the Weddell
Seal) rather feeble, among the range in animals able to cope in water rather
than those that have to exist in it permanently of for much of their time."
- Just so story. |
3. Fossil evidence. Hardy - need to look in different places. Morgan
contests that fossil evidence is intrinsically more valid than other
evidence.
Takes
Morgan
to task for citing a' piths as potential swimmers when they show no signs of
swimming. (streamlining etc.)
"Fortunately for
the AAT supporters the aquatic phase took
place
during the undocumented gap in the fossil record before 4mya, presumably at
the same time they believe we were losing our hair in order to be able to
swim faster than sharks." p138
Conclusion
"what is apparent from these in-house disputes, however, is the need for an
awareness of the basic issues involved, and the theoretical underpinnings of
the subject."-like
humans
competing with sharks!
"There is more to understanding evolution" he concludes p 140 "than a belief
in natural selection and the construction of adaptationist scenarios, and if
specialists can be shown to have fallen into that trap then the non
specialists may need to exercise great caution." p 140.
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Counter-Arguments
Clearly Turner has made an impression in the official circles.
Many
(e.g. Aeillo at UCL)
call the
AAT a 'Just
so story' and Collard
(also at UCL)
used the facile
'bike
analogy' too.
1. Bikes did not exist in the Pliocene. Nor did musical instruments etc. We
are capable of many things but if you strip away technology we are not
capable of many of them - e.g. living in polar or mountainous regions.
Wading,
Swimming and diving on the other hand are hindered not helped by technology
(clothing) we can swim perfectly adequately naked.
2. The "We
experts know best"
ex cathedra argument is not very convincing. If the AAT is so weak
professional paleoanthropologists should be able to run rings around it, but
they can't.
Academic inculturation is a known phenomenon.
The AAH
has never even
been
properly
studied
so how can experts claim to have even considered it, let alone dismiss it.
3. Macro-climate changes. The fact of Africa drying is not in dispute. The
consequences are. If it gets drier forests shrink nearer to water and
hominids would become even more dependent on it.
This is the basic principle of my 'River
apes' model.
4.
Hair
loss helps swimming speed - fact.
Although in 1987 Hardy's claim that shaving body hair
made a difference to
human swimming speed might have sounded far fetched, he has since been
proved right. For example
Sharp & Costill (1989) showed clearly that even
shaving off a bit of body hair gives a 3-4% speed
improvement and better measurements in terms of anaerobic efficiency. This,
remember is scientifically tested in
young
human males -
what if it had been
someone as hairy as
a chimp?
Other studies have confirmed
this independently.
His counter argument? - "are we really to believe that a swimming primate in
a life-or-death contest with a superb swimmer such as a shark would achieve
much by the loss of body hair?" - arguing by personal incredulity is rather
weak.
Swimming events
need not be very frequent. Even once a week would amount to hundreds in a
lifetime before
maturity is reached.
5. Comparing us with seals to say how feeble we are completely misses the
point.
It ignores the crucial
consideration of cladistics.
The only
valid comparison is with chimpanzees - our nearest relative and we theirs.
Compared to them we are supremely adapted to water.
6. The timescale point is fair. Hardy/Morgan never focused in on it
enough.
I
take
Verhaegen's line on
that -
at least
up to 3mya:
An
aquatic ape living in aquarboreal wading niche. Chimps/gorillas became more
terrestrial humans more aquatic. That makes sense.
7. Astonishingly
arrogant ex cathedra view - especially when he clearly demonstrates
that he hasn't even
grasped
one of the most basic concepts of evolution himself.
The
putative swimming
hominids are not
competing with shark
predators, but with each other,
as anyone who knows about Darwinian natural selection should know!
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