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



Algis Kuliukas wrote:
> JAE wrote:
> > Algis Kuliukas wrote:
> > > JAE wrote:
> > [snip]
> >
> > > In gallery forest habitats prone to flood-desiccation cycles bipedal
> > > wading is going to have clear survival benefits in flood cycles, and
> > > walking efficiently on drying river beds is going to have clear
> > > survival benefits during dry phases. What's your problem with that?
> >
> > You are still not addressing the survival value. Why is the
> > facultative biped at a disadvantage? My problem is that you've got no
> > selection in a adaptationist argument. There's nothing in your
> > argument that differentiates between the facultative biped standing up
> > and the obligate biped that relates to water.
>
> I don't recognise the distinction. They were *all* facultative bipeds
> at the stage I'm assuming this was important. Facultative bipeds that
> were evolving, step by step, towards obligate bipedalism. There were no
> obligate bipeds to compete with, just other, slightly more or slightly
> less, facultative bipeds.

The distiction early on was indeed artificial. But the characteristics
were evolving in a direction. How does looking more like the obligate
biped relate to a survival advantage?

> What gave some of them advantages over others? It's multi-faceted.
>
> During wet phases, when wading was more important:
> Stability of footing and being longer legged (makes them less likely to
> drown) - likely to favour traits like more flat footedness, longer
> legged and more urpight curvature of lower spine.

Since the early bipeds *weren't* long legged, how is this relevent?
Since bipeds are not flat footed at all, but have arched (medial and
longitudinal) feet how do you explain flat footedness as an advantage
when we've not gone in that direction at all? How does the curvature
of the spine relate to a survival difference?

> During dry phases, when walking was more important:
> Greater efficiency of movement on dry ground (more likely to find food
> and water at less cost during harsh times) - like to favour long
> leggedness, traits to optimise gait etc.



> > >
> > > I think you're being too pedantic here. When I suggest that it is in
> > > sub-waist deep water that some (literally watered down) need for the
> > > traits of a terrestrial biped may be selected for, I'm not suggesting
> > > that they spent there lives in that twilight zone. It's just a fact
> > > that as one wades through water there is a continuum of depths. As the
> > > water level goes down there is a shift in locomotor requirements: Less
> > > physical work has to be done to propel the body forward, but more work
> > > has to be done keeping one's balance. It's this shift, that must have
> > > happenned thousands of times in the lifetime of a gallery-forest
> > > dwelling hominid, that honed in those traits that would act as the
> > > perfect precursor to human bipedalism.
> >
> > What is the selective process here? What killed off the facultative
> > bipeds? What made them have fewer babies?
>
> In wet spells predation and drowning would have been a major factor
> killing off early hominins, in dry spells predation, starvation and
> thirst - and specifically an inability to find food and drink often
> enough, efficiently enough, would have been a major killer. You know,
> the usual.

This didn't answer the question at all. Why does the facultative biped
drown? Why is it at a disadvantage?

> > [snip]
> >
> > > I do think it is astonishing that for 150 years paleoanthropologists
> > > have scratched their heads on bipedal origins when, staring them in the
> > > face, they could have gone to any zoo with a moat and seen that apes
> > > move bipedally most predictably even in the shallowest of water. It's
> > > obviously a big part of the answer. I think the tax payer would have
> > > expected a better return from their input. I think they'd be appauled
> > > if they knew how such a simple, plausible idea had been dismissed on
> > > the basis of so little scientific enquiry.
> >
> > You joining Pauli on this "tax payer" kick, huh? This scenario where
> > the general public's democratic cries decide what is and isn't good
> > science? In the U.S. the "tax payers" as a whole would vote to fund
> > "research" into "intelligent design" and 7-day creationism. You're
> > raising a red herring.
>
> Ok, good point. But perhaps in Europe the public are a little more
> critical. Who knows. Anyway, substitute 'science expenditure watchdog'
> for tax payer and you get the same point. 150 years of research into
> human evolution and very little real progress.

You should read (or reread) Descent of Man if you really believe that
there's been no progress in 150 years. There has been much progress.
Do not confuse still having many questions with no progress.

.