Re: Homo : glacials = more marine exploitation?

On Feb 23, 2:12 am, rmacfarl <rmacf...@xxxxxxxxxxxxxxxx> wrote:
On Feb 23, 5:57 pm, rmacfarl <rmacf...@xxxxxxxxxxxxxxxx> wrote:



On Feb 22, 9:10 pm, Marc Verhaegen <m_verhae...@xxxxxxxxx> wrote:

Neandertal diet was not dolphin-safe

Chris Stringer and colleagues (including Finlayson and Barton) have a paper
in the current PNAS early bin describing Neandertal exploitation of marine
mammals in the Gibraltar caves (Vanguard and Gorham's). The Neandertals left
some seals and dolphin bones with cutmarks behind, along with a lot of
mollusk shells.

When I pulled up the paper, it sounded very familiar to me, like I'd written
about it before. And indeed, I had, although I hadn't posted the results. A
couple of years ago I was doing some research on the Gibraltar caves and I
ran across a website from Oxford covering the Gibraltar excavations....

Credit where it's due, which means not to Marc. Anyone unfamiliar with
the Belgian bonehead's esoteric vernacular could be fooled into
thinking that that passage, which Marc posted without attribution,
referred to work he had done himself. Of course, it didn't. The whole
passage was written by John Hawks on his blog, from whence Marc cut &
pasted it:

http://johnhawks.net/weblog/reviews/neandertals/diet/gorhams-vanguard...

Posting someone else's work under your own name without attribution
Marc? That's called "plagiarism", didn't you know that? That would get
you sacked instantly from an academic or journalistic posting. Good
thing no university or science magazine have ever been misguided
enough to give you a job...

Ross Macfarlane

And in case anyone should be wondering how Hawks regards the aquatic
ape theory:

http://johnhawks.net/weblog/topics/pseudoscience/aquatic_ape_theory.html

Here it is:

One of the most common arguments about human evolution on the Internet
is whether hominids ever went through an "aquatic phase" in their
evolution. The Aquatic Ape Theory proposes that such an aquatic phase,
during which ancestral hominids relied on a water habitat, explains
much of the distinctive anatomy of recent humans. Proponents of the
Aquatic Ape Theory compare the predictions of their model with the
predictions that they derive for a traditionalist model, which they
term the "Savanna model". In their view, an aquatic phase provides a
better explanation for many human characteristics that the savanna
model finds difficult to explain.
For example, why do humans lack fur? Most anthropologists believe the
lack of fur derives from selection associated with thermoregulation.
In this account, humans are unlike most primates in using sweating as
a significant source of evaporative heat loss. This system is
efficient in humans because it exploits the latent heat of
condensation to carry away much more heat than is possible through
radiation, convection, or shade alone. But sweating would not work on
a furry hominid, because evaporation from the fur does not carry away
nearly the amount of heat lost by direct skin transfer.
The Aquatic Ape Theory rejects this hypothesis, noting that:
the mechanism of sweating in humans is especially wasteful of water--a
rare commodity in the hot savanna
other medium-sized mammals in the hot savanna environment do not use
this mechanism of heat loss
the loss of fur has required the development of a significantly costly
form of insulation for the human body, a relatively thick layer of
subcutaneous fat
By this argument, the theory proposes that it makes more sense that
humans developed hairlessness and their unique glandular system of
sweating in an environment where water was both plentiful and
continuously available.
Several other distinctive human features are treated by this
hypothesis. Bipedalism itself is suggested for its value in wading
into moderately deep bodies of water.
If the Aquatic Ape Theory explains so much, why do the majority of
anthropologists not subscribe to it? It is hard to find a clear answer
to this question on the Internet. Responses to the Aquatic Ape Theory
both on Web sites and on Internet news groups tend to digress into the
a number of specific topics that detract from an answer this question
instead of answering it. Consider the following list of responses:
"Hominids leading into the water sources available to them would have
nothing to protect them from crocodiles and other large predators."
"Paleontologists have never found fossil evidence of this aquatic ape.
"
"There may be gaps in the fossil record, but it is unlikely that those
gaps will be filled by new primates and entirely different from any
known form in their ecology."
Supporters of the Aquatic Ape Theory can provide answers to each of
these questions. They can talk about the great quantity of littoral
resources for a primate foraging along the seashore. They can talk
about the rarity of crocodiles along the seashore and the failure of
other land predators to pursue their prey into the waves. The can talk
about the geological record of sea level changes, as the reason that
geological strata that might contain these ancestors like inaccessible
to paleontologists.
And they can continue to criticize the "Savanna model" as inadequate
to explain human features-especially soft tissue characteristics. This
process itself displays an element of the disingenuousness,
considering that the fossil evidence increasingly suggests that
hominids did not originate on the savanna at all. In fact all hominid
sites earlier than around 3 million years appear to represent woodland
of an open or closed nature. It appears quite evident now that our
"descent from the trees" didn't take us out of the woods. As the
present evidence continues to develop, the Aquatic Ape debate gets
farther and farther from relevance.
But if all these issues are distractions, how can we explain the
reluctance of anthropologists to seriously examine the Aquatic Ape
Theory? Proponents of the theory tend to argue that this is more than
blindness on the part of the paleoanthropological establishment.
Instead, they argue, professional paleoanthropologists are engaged in
a more or less deliberate conspiracy to exert their hegemonic control
over the field by a marginalizing alternative viewpoints.
In this, some proponents of the Aquatic Ape Theory take the same
position as creationists, arguing that it is the dominant culture of
science rather than the intrinsic value of current scientific ideas
that excludes them from debate.
Like most other professional anthropologists, I am well aware that
there is no active conspiracy under way to preclude strange ideas from
scientific evaluation. In fact I have seen many strange ideas come
down the pike over the years that received far more celebrity than
notoriety. The history of new research in the field will show to any
close observer the value of breaking with scientific norms. This is so
much the case in the study of human evolution that has provoked
published complaints on the part of senior scientists. But despite
these grumblings, there is nothing that anyone can do to prevent the
publication of credible research in the field, and little they can do
to prevent the publication of incredible research. There is much more
to be gained for young scientists in pushing a new or outlandish idea
that has serious empirical support than in mindlessly following the
dictates of the aging graybeards.
From this I think we can conclude at least something small: that many
anthropological eyes looking over the predictions of the Aquatic Ape
Theory would have found by now some serious reasons to support it, if
there were any.
But there is more than a small reason why the Aquatic Ape Theory is
not believed by anthropologists. The large reason is parsimony.
Evaluating the parsimony of hypotheses is a fundamental aspect of the
scientific method. The idea is that hypotheses differ with respect to
the kind of assumptions that the requires to make. Some hypotheses
require a large number of assumptions, others require fewer
assumptions. Some hypotheses require fairly extraordinary assumptions.
One of the characteristics of parsimony is the ability of a hypothesis
to link many different effects with a single cause. It is under this
qualification that the Aquatic Ape Theory appears very appealing. By
positing a single assumption -- that as yet undiscovered hominids
lived in a unique aquatic environment -- the theory is able to
encompass the evolution of several different characteristics of the
human body that otherwise would not appear to be tightly linked to
each other. In other words, the hypothesis appears to be simple as an
explanation for many different characteristics, requiring only one
assumption (and its many associated effects) instead of a separate
evolutionary explanation for every characteristic.
But this appeal ignores another fundamental characteristic of
parsimony: a hypothesis that depends on one explanation is more
parsimonious than a hypothesis that invokes multiple explanations.
Consider the proposed "aquatic phase" of human evolution, which the
Aquatic Ape Theory posits to explain human characteristics that are
uncommon in land mammals. Certainly it makes sense that hominids would
develop new anatomies to adapt to such an alien environment. But once
those hominids returned to land, forsaking their aquatic homeland, the
same features that were adaptive in the water would now be maladaptive
on land. What would prevent those hominids from reverting to the
features of their land-based ancestors, as well as nearly every other
medium-sized land mammal? More than simple phylogenetic inertia is
required to explain this, since the very reasons that the aquatic ape
theory rejects the savanna model would apply to the descendants of the
aquatic apes when they moved to the savanna. This is far from trivial,
since fossil hominids did inhabit open woodland starting by 6 million
years ago, and did move to open savanna by 3 million years ago.
Nor can the theory hide behind the idea of exaptation. One might
propose that the features that were originally adapted in the aquatic
environment found new purposes when the formerly aquatic apes moved
onto land. But each of these features still requires an adaptive
explanation for why it would be maintained. And each of these adaptive
explanations would probably be equally credible as an evolutionary
hypothesis for the origin of the characteristics outside the aquatic
environment.
In other words, the Aquatic Ape Theory explains all of these features,
but it explains them all twice. Every one of the features encompassed
by the theory still requires a reason for it to be maintained after
hominids left the aquatic environment. Every one of these reasons
probably would be sufficient to explain the evolution of the traits in
the absence of the aquatic environment. This is more than
unparsimonious. It leaves the Aquatic Ape Theory explaining nothing
whatsoever about the evolution of the hominids. This is why
professional anthropologists reject the theory, even if they haven't
fully thought through the logic.

I couldn't have said it better myself!
-Spiznet
.

Relevant Pages

  • Re: Homo : glacials = more marine exploitation?
    ... the criticisms of Hawks reveal mainly his ... "Savanna model". ... If the Aquatic Ape ... evidence increasingly suggests that hominids did ...
    (sci.anthropology.paleo)
  • the more "professional", the more lunatic... :-D
    ... Why anthropologists don't accept the Aquatic Ape Theory - One of the most ... ever went through an "aquatic phase" in their evolution. ... Theory proposes that such an aquatic phase, during which ancestral hominids ...
    (sci.anthropology.paleo)
  • Re: The Aquatic Ape Theory
    ... >> weight to the AAT." ... >> apes, not even about australopiths, but only about Homo. ... "Aquatic ape theory" is not wrong, but some simple minds get curious ideas ...
    (sci.anthropology.paleo)
  • Re: For Daryl K. :Wikipedia entry for "human origins" (Aquatic part)
    ... The aquatic ape hypothesis of human evolution proposes a novel answer ... that at some time in evolution humans were coastal dwelling primates. ... aquatic ape theory of human evolution. ...
    (sci.anthropology.paleo)
  • Re: The Aquatic Ape [Was: Asleep at the idiot box]
    ... concentrations and were exapted into an enormously poorly designed ... temperature regulation device. ... *please* tell me you're not still a subscriber to the Aquatic Ape ... If one dumps the Aquatic Ape theory, how does one account for the ...
    (alt.usage.english)