origins of bipedalism (Re: A critique of the BBC aquatic ape programme and the transcript.

"Algis Kuliukas" <algis@xxxxxxxxxxxxx> wrote in message
news:1121865328.395831.12940@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx

>> > Heck, even your own paper Verhaegen et al (2002) refers to wade/wading
>> > in the context of bipedalism 24 times, including this... "We find
>> > nonwading explanations for human bipedalism [1-3] (e.g. standing up to
>> > reach fruit in trees, aggressive posturing, looking over savannah grass
>> > and carrying tools, food or babies) unconvincing, because the
>> > advantages appear to be only of a temporary nature, and because no
>> > other primates or savannah mammals have developed bipedalism for
>> > similar reasons." Verhagen et al (2002:212)

>> Yes. And? Does this mean we find the wading explanation convincing??

> So when you wrote that, you really, secretly meant that you *didn't* find
> it convincing?

secretly?? You're a bit paranoic, Algis - no wonder after all your
"discussions" with the dry ape fools here... :-D
1) It's no question of conviction, but of data! We left the question open:
IMO we don't have enough data at this moment. So difficult IYO??
2) I guess (not enough comparative data, but see below) that wading was part
of how our locomotion evolved, although I don't see how & why they would
have waded exactly (for salmon? cf grizzleys on 2 legs? for cattails?),
except perhaps in the very latest phase (eg, early-sapiens? fishing with
nets??).
3) All wading mammals are quadrupedal, so obviously wading is not the key
factor. If non-human waders are quadrupedal, how can you argue that wading
leads to bipedalism?? For some reason, you believe that humans are an
exception - very unscientific attitude, Algis. Lowland gorillas wade usu.on
2 legs in forest swamps, but walk usu.on 4 legs on land.

> Is that what you're saying now? Why do you have to talk in riddles? Why
> not just say what you *do* think so that we don't have to second guess
> you're meaning all the time?

Why on earth should you want to guess what I mean?? I don't feel the need to
guess what you mean, Algis... My meaning is unimportant: just look at the
facts & think a bit.

> Look. At least have the honesty to admit that it's confusing, Marc. You
> published a paper where you say you find *non*wading explanations for
> bipedalism unconvincing and now, just three years later, you're acting all
> surprised that people should consider a wading origin for bipedalism part
> of the AAH. (e.g. "AAT does not claim for the evolution of bipedalism.")

consider? Where did I say that we shouldn't consider wading??? Please, a
bit honest, Algis...

>> Again: all non-human wading mammals are quadrupedal! Is this my fault??

> It is your fault that you don't seem to see the significance of the fact
> that apes (our own clade remember) are most predictably bipedal in depths
> of water where practically every other mammal is quadrupedal or would
> swim. I just find it bizarre that I'm having to argue with you about such
> things. Who would have thunk it?

You, if you had used your brain a bit: just compare how lowland gorillas
move in water & on land.

>> > In fact I thought it was the AAH's strongest and most demonstrable
>> > argument as water is clearly the factor which compels apes to move
>> > bipedally. That's why I've been studying it for the last five years.

>> Why do you want to put everything in a wading basket??

> I'm not putting *everything* in the wading basket, I'm putting *bipedal
> origins* in the wading basket.

Sorry, I meant: Why do you put human locomotion in a wading basket?

As for *bipedal origins*, a lot of Mio-Pliocene apes are believed to have
been "bipedal" (Oreopith, Sahelanthr, Orrorin, Ardipith, Australopith), but
I don't see how this can explain human but not Afr.ape locomotion.

> I'm doing this because apes are most predictably bipedal in depths of
> water where practically every other mammal is quadrupedal or would swim. I
> think that is a bit of a clue. I think it's certainly a much more
> compelling argument

Ah?? Why don't you look at gorillas in water & on land?

> than the notion that diving (a horizontal, effectively weight*less* form
> of locomotion) had anything to do with the origin of humanlike bipedalism
> (a vertical, weight *bearing* form of locomotion.) Algis

- "horizontal diving"? What might that be?

- As I argued numerous times, our *bipedal origins* lie obviously in our
arboreal past.
(I'm less sure whether all bipedalisms originated in the trees: birds &
kangaroos yes, likely, but, eg, Pedetes?)

- It's clear that our locomotion is unique, so if you want to explain it,
you have to analyse it:
1) plantigrade (unlike ostrich)
2) striding (unlike indri hopping)
3) long legs (unlike Lucy)
4) aligned body (unlike ostrich)
5) bipedal (unlike tapir wading)
etc.
Now, look at groups of 2 of these elements and try to find examples. For
simplicity, look only at bipeds. Most bipeds are birds, but that's no
problem: bats & birds also belong to different orders & have converged
strongly.
1+2) penguin, wading-birds? Do wading-birds hop AFAYK?
1+3) kangaroo=plantigrade? predom.wading-birds? Perhaps we have your
wading-argument here, Algis!? :-)
1+4) penguin, no others??
2+3) ostrich, heron...
2+4) penguin, others??
3+4) example? unique?? If unique, long legs & aligned body have to be
explained by different locomotions?
Algis, if you want to know how much our ancestors waded, I think you have to
make a study of wading-birds (body size? diet? rel.leg length? aligned body?
BHBK? plantigrady? foot length? striding? broad body? valgus? lifestyle
incl.flying? diving? beach-combing? running on dry land? etc.), and compare
them to other birds.
In any case, our locomotion perfectly fits our scenario that our Homo
ancestors were once seaside omnivores who collected coconuts, fruits, bird
eggs, turtles, shell-, crayfish, algae... This explains many typically Homo
traits (ie, not seen in apes or apiths) a lot better than all other
scenarios do AFAIK (or do you have an alternative? :-)): brain size, diving
skills, breathing control, vocality, small mouth & chewing muscles, hyoid
descent, longer airway, projecting nose, reduced olfaction, handiness, tool
use, late puberty, long legs, body alignment, reduced climbing, fatness, fur
loss, high needs of water, sodium, iodine & poly-unsaturated fatty acids
etc. This waterside episode is clearly reflected in the Plio-Pleistocene
diaspora of Homo along the Afr.& Indian Ocean coasts: 1.8-Ma Homo remains
come from Algeria, Iran, Kenya, Georgia, Java... always near lakes or seas
(R.Dennell 2003 JHE 45:421). Homo much more than apith remains have been
found amid shells, corals & barnacles, from 1.8 to 0.1 Ma, ie, throughout
the Pleistocene, in coasts all over the Old World: Mojokerto, Terra Amata,
Table Bay, Eritrea, even on islands that could only be reached by sea, eg,
Flores 0.8 Ma http://allserv.rug.ac.be/~mvaneech/outthere.htm
http://www.onelist.com/community/AAT
http://groups.yahoo.com/group/AAT1

--Marc


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Relevant Pages

  • Re: AAT = (Plio)Pleistocene Homo spread along the coasts & got a littoral diet.
    ... Sorry, Algis, I have no time to read it all again. ... >> water, IOW, it's probably the climbing past that makes the difference. ... Aquarboreal doesn't mean it necessarily includes wading. ... > terrestrial but still no tendency towards bipedalism there either. ...
    (sci.anthropology.paleo)
  • Re: AAT = (Plio)Pleistocene Homo spread along the coasts & got a littoral diet.
    ... Algis. ... > that led to the evolution of hominid bipedalism? ... Because, for the Xth time, no wading mammals are bipedal. ... IMO your hybridisation view is wrong: living humans show very little ...
    (sci.anthropology.paleo)
  • Re: Bipedalism in different substrates
    ... >kind of statement that proto-hominin x ate food source y in habitat z ... parsimoniously infer that proto-hominins may have eaten a wide variety ... underlie selection leading to obligate terrestrial bipedalism. ... >wading they did, the more bipedal they would become. ...
    (sci.anthropology.paleo)
  • Intellectual Stealth
    ... Does this mean we find the wading ... You're a bit paranoic, Algis - no wonder ... IOW, Marc, you don't find the data convincing? ... >> for bipedalism unconvincing and now, ...
    (sci.anthropology.paleo)
  • Re: AAT = (Plio)Pleistocene Homo spread along the coasts & got a littoral diet.
    ... Marc Verhaegen wrote: ... > Aquarboreal doesn't mean it necessarily includes wading. ... Why does surface swimming act as a good precursor to bipedalism? ... Algis!? ...
    (sci.anthropology.paleo)
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