https://www.nature.com/articles/s41559-022-01929-2
Published: 05 January 2023

Abstract
The longitudinal arch of the human foot is viewed as
a pivotal adaptation for bipedal walking and running.
Fossil footprints from Laetoli, Tanzania, and Ileret,
Kenya, are believed to provide direct evidence of
longitudinally arched feet in hominins from the
Pliocene and Pleistocene, respectively. We studied
the dynamics of track formation using biplanar X-ray,
three-dimensional animation and discrete element
particle simulation. Here, we demonstrate that
longitudinally arched footprints are false indicators
of foot anatomy; instead they are generated through a
specific pattern of foot kinematics that is
characteristic of human walking. Analyses of fossil
hominin tracks from Laetoli show only partial evidence
of this walking style, with a similar heel strike but
a different pattern of propulsion. The earliest known
evidence for fully modern human-like bipedal kinematics
comes from the early Pleistocene Ileret tracks, which
were presumably made by members of the genus Homo. This
result signals important differences in the foot
kinematics recorded at Laetoli and Ileret and underscores
an emerging picture of locomotor diversity within the
hominin clade.

"The longitudinal arch is often cited as an important
evolutionary innovation of the human foot that contributed
to proficient bipedal walking and adept endurance running
in our fossil relatives..."

"Given the challenges of interpreting arches from fossil
feet, the Laetoli and Ileret tracks are considered the
least equivocal evidence for a deep history of
longitudinally arched foot morphologies in hominin
evolution."

"While isolated analyses of skeletal fossils have
generated conflicting interpretations about whether
the A. afarensis foot functioned like that of a modern
human, our analysis of the arched Laetoli footprints
provides a unique kinematic synthesis. Brought into view
through this new lens is a pattern of foot function and
bipedal locomotion that was human-like in some ways
yet still importantly different."

"In contrast, 1.5 Ma tracks from Ileret, Kenya, preserve
the earliest evidence for a fully human-like pattern of
foot kinematics. Tracks from Ileret (total n = 4 from
three trackways) have RAVs where we would expect similarly
deep modern human tracks to fall (Fig. 4a). These data
provide new evidence to support inferences of human-like
foot kinematics in Homo erectus. We emphasize, however,
that our track ontogeny results simultaneously invalidate
direct association between arched footprint morphology and
arched foot anatomy at Ileret11. In contrast with the
Laetoli examples above, it appears that the Ileret tracks
are fully consistent with not only a heel–sole–toe rollover
pattern but also a pattern of forefoot propulsion closer to
that observed in modern humans."

"The results of our track analyses suggest that important
changes to foot anatomy and function occurred at or before
the emergence of the genus Homo, where a suite of postcranial
changes could correspond to selective influences of locomotor
behaviours such as long-distance walking or endurance running."

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Pro Plyd wrote:

Fossil footprints from Laetoli, Tanzania, and Ileret,
Kenya, are believed to provide direct evidence of
longitudinally arched feet in hominins from the
Pliocene and Pleistocene, respectively.

Odd that the fossils would not.

And what does "Believed" mean in your native tongue?

Who believes? And was there a poll taken? Who were
the participants?

If you want to "Argue" a position then argue a position,
but you want to preach the gospels here, and you're
just not good at it. At all.

Here, we demonstrate that
longitudinally arched footprints are false indicators
of foot anatomy;

Hmm. This doesn't seem to be saying what you think it's
saying.

"Their feet were arched! Well, no they weren't. The footprints
are false indicators of arched feet. But they were arched."

instead they are generated through a
specific pattern of foot kinematics that is
characteristic of human walking.

You mean "Bipedal" locomotion?

The earliest known
evidence for fully modern human-like bipedal kinematics
comes from the early Pleistocene Ileret tracks, which
were presumably made by members of the genus Homo.

And yet you "Believe" that this is proof of something else...

So the piece is saying that there's a difference between
THESE footprints here and THOSE footprints there, and
that your arched feet aren't arched but only look arched
because of the way they walked... and that only Homo
had arched feet.




-- --

https://jtem.tumblr.com/post/715256725101592576

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https://www.nature.com/articles/s41559-022-01929-2
Published: 05 January 2023 Abstract
The longitudinal arch of the human foot is viewed as
a pivotal adaptation for bipedal walking and running.

:-DDD "viewed" by whom??
Don't waste your time with reading the rest of these prejudices.

Cursorial=runnning mammals are invariably not plantigrade, but
- cursorial herbivores are typically unguligrade: hooves (3rd or 3rd+4th rays are much longer),
- cursorial carnivores: digitigrade: claws (middle digital rays are longer).

Human feet are plantigrade + rel.very long 1st & 5th digital rays:
only incredible imbeciles think these feet were "cursorial".

Hominoid & Homo evolution is not so difficult if we use simple comparative data:
- Mio-Pliocene "apes" (hominoids) were (google) "aquarboreal",
- early-Pleistocene (perhaps already late-Pliocene) Homo also frequently dived for shellfish etc.
https://www.gondwanatalks.com/l/the-waterside-hypothesis-wading-led-to-upright-walking-in-early-humans/

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peter2...@gmail.com wrote:

On Thursday, July 13, 2023 at 2:20:38 PM UTC-4, JTEM is my hero wrote:

Pro Plyd wrote:

JTEM is my hero wrote:

Pro Plyd wrote:

Fossil footprints from Laetoli, Tanzania, and Ileret,
Kenya, are believed to provide direct evidence of
longitudinally arched feet in hominins from the
Pliocene and Pleistocene, respectively.

Odd that the fossils would not.

Really? Why do you believe that?

If you had reading comprehension, you could read the
above and see that they are claiming that it's footprints,
not fossils, which are the evidence.

"Fossil footprints" was the term used, and the technical term
for them is "ichnofossils" and the less technical but still
official term is "trace fossils."

And ichnofossils are indeed evidence.

Where do you get "not fossils"?

I thought it was clear that it was speaking of footprints...

oo! I know: It just never occurred to you that you don't
need to establish things that are already established.

That, if fossils establish something, you don't need
footprints to establish it.

You allege that fossils [of foot bones] established it? Where is your evidence for that?

The stems from his ignorance regarding ichnofossils. Paleontology
records and reports on finds like footprints. For example

http://onlinelibrary.wiley.com/doi/10.1111/let.12098/abstract
Estimating body weight and habitat type from extinct avian
and avian-like theropod footprints

These are every bit as valid a bit of evidence as a bone.

And also the gratuitous assumption that all this arch stuff had to be the result of Aquatic Ape behavior. Or beneficial to it.

Marc keeps trying to simulate a connection by juxtaposing the two
things, arches and aquatics, but never producing anything but more juxtaposition.

He reminds me of creationists who try to associate all kinds of
phenomena with the Noah Flood, including the glaciers
that covered half of North America.

That's insulting to creationists.

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