Troubling the waters of anthropology:
Is wading the missing factor in the evolution of hominid bipedalism?
AV Kuliukas, N Milne & P Fournier 2010 AAPA

Largely missing from the debate about the evolution of hominid BPism is a discussion of the possible role of wading in shallow water.
We review the literature that considers the concept,
we suggest that it is the idea’s mere association with the "aquatic ape hypothesis" which accounts for its disapproval:
specific objections are largely absent.
Outstanding questions exist about hominid origins relating to how BPism may have been practiced, before traits evolved to make that mode of locomotion efficient.
Recent findings have suggested solutions to these problems.
One such study suggested that early hominids already walked with a Fully-upright (FUp) gait, by showing that the Bent-Hip-Bent-Knee (BHBK) gait is 50-60 % more energetically costly than a FUp human gait on land.

Here, I report a similar study which confirmed these findings, but also showed that in water the cost differential between these gaits is markedly reduced, esp.
-in deeper water,
-at slower speeds,
-with greater knee flexion, e.g.
-- walking in waist-deep water, at 0.6 m/s, with a 50° knee flexion, reduced the cost differential between FUp & BHBK gaits to 18 % (p<.001),
-- moving through water to the depth of the xiphi-sternum, at 0.3 m/s, there was no significant difference at all (p=.631).

On the basis of these findings, wading appears to be an extra factor, which can only add value to the various models that have been published regarding the evolution of early forms of “non-optimal” hominid BPism.

littor...@gmail.com wrote:

> we suggest that it is the idea’s mere association with the
> "aquatic ape hypothesis" which accounts for its disapproval:
> specific objections are largely absent.

Technically, it's not "Aquatic Ape" per se. It's the fact that it
contradicts the official OOA narrative. Wouldn't matter if it was
Aquatic Ape, Out of Asia or Multiregionalism, if it contradicts
the official narrative then it is rejected.

But bipedalism makes sense in the context of Aquatic Ape.
Obviously we can't hold our breath for hours, we never evolved
that ability, so the further out we want to reach, collecting &
carrying a load of shellfish (probably), the more we needed to
stand with our heads above the water.

Standing upright translates directly to moving out further/deeper
into the water without having to hold our breath.

It increases our foraging range, the amount of food available to
us.

Resources that were available at low tide would be reachable in
high tide. Even resources beyond that could be reached.

-- --

https://jtem.tumblr.com/post/657086938953777152

Algis Kuliukas still believes our waterside ancestors lived +-like waterside humans today,
but our ancestors were anatomically clearly different from us:
-- Pleistocene Homo: pachyosteosclerosis, platycephaly, full plantigrady, platymeria, platypelloidy, brain enlargement, shorter legs, wider thorax, more projecting nose...:
obviously "archaic" Homo (e.g. erectus) were predom.shallow-water divers, most likely for shellfish etc.
-- Pliocene hominids: +-australopith-like: obviously "aquarboreal" (google)..

______

Op maandag 19 juli 2021 om 18:55:50 UTC+2 schreef I Envy JTEM:

> > we suggest that it is the idea’s mere association with the
> > "aquatic ape hypothesis" which accounts for its disapproval:
> > specific objections are largely absent.

> Technically, it's not "Aquatic Ape" per se. It's the fact that it
> contradicts the official OOA narrative. Wouldn't matter if it was
> Aquatic Ape, Out of Asia or Multiregionalism, if it contradicts
> the official narrative then it is rejected.
>
> But bipedalism makes sense in the context of Aquatic Ape.
> Obviously we can't hold our breath for hours, we never evolved
> that ability, so the further out we want to reach, collecting &
> carrying a load of shellfish (probably), the more we needed to
> stand with our heads above the water.
>
> Standing upright translates directly to moving out further/deeper
> into the water without having to hold our breath.
>
> It increases our foraging range, the amount of food available to
> us.
>
> Resources that were available at low tide would be reachable in
> high tide. Even resources beyond that could be reached.