New fossils of Australopithecus sediba reveal a nearly complete lower back

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Primum Sapienti

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Nov 24, 2021, 1:35:51 AM11/24/21
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Paper is public

https://elifesciences.org/articles/70447

Abstract
Adaptations of the lower back to bipedalism are frequently discussed but
infrequently demonstrated in early fossil hominins. Newly discovered lumbar
vertebrae contribute to a near-complete lower back of Malapa Hominin 2
(MH2), offering additional insights into posture and locomotion in
Australopithecus sediba. We show that MH2 possessed a lower back
consistent with lumbar lordosis and other adaptations to bipedalism,
including
an increase in the width of intervertebral articular facets from the upper to
lower lumbar column (‘pyramidal configuration’). These results contrast with
some recent work on lordosis in fossil hominins, where MH2 was argued to
demonstrate no appreciable lordosis (‘hypolordosis’) similar to Neandertals.
Our three-dimensional geometric morphometric (3D GM) analyses show that
MH2’s nearly complete middle lumbar vertebra is human-like in overall shape
but its vertebral body is somewhat intermediate in shape between modern
humans and great apes. Additionally, it bears long, cranially and ventrally
oriented costal (transverse) processes, implying powerful trunk musculature.
We interpret this combination of features to indicate that A. sediba used its
lower back in both bipedal and arboreal positional behaviors, as previously
suggested based on multiple lines of evidence from other parts of the
skeleton
and reconstructed paleobiology of A. sediba.

"...the lower part of the human spine has a forward curve that supports an
upright posture; whereas the lower backs of chimpanzees and other apes –
which walk around on four limbs and spend much of their time in trees – lack
this curvature."

"The new fossils are mainly bones from the lower back, and they fit together
with the previously discovered MH2 fossils, providing a nearly complete lower
spine. Analysis of the fossils suggested that MH2 would have had an upright
posture and comfortably walked on two legs, and the curvature of their lower
back was similar to modern females. However, other aspects of the bones’
shape suggest that as well as walking, A. sediba probably spent a significant
amount of time climbing in trees."

"Despite the presence of climbing adaptations, A. sediba also demonstrates
clear evidence for bipedal locomotion. The knee and ankle possess human-like
adaptations to bipedalism, demonstrating a valgus angle of the femur and a
human-like ankle joint..."

"Furthermore, analysis of dental calculus from Malapa Hominin 1 (MH1)
indicates
that this individual’s diet was high in C3 plants like fruit and leaves,
similar to
savannah chimpanzees and Ardipithecus ramidus..."



littor...@gmail.com

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Nov 24, 2021, 9:03:52 AM11/24/21
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> https://elifesciences.org/articles/70447

:-)
= wading bipedally + climbing arms overhead in swamp forest, as we predicted >20 years ago,
google our Trends paper "Aquarboreal Ancestors?".

> ... Newly discovered lumbar
> vertebrae contribute to a near-complete lower back of Malapa Hominin 2
> (MH2), offering additional insights into posture and locomotion in
> Australopithecus sediba. We show that MH2 possessed a lower back
> consistent with lumbar lordosis and other adaptations to bipedalism,
> including
> an increase in the width of intervertebral articular facets from the upper to
> lower lumbar column (‘pyramidal configuration’). ...
> MH2’s nearly complete middle lumbar vertebra is human-like in overall shape
> but its vertebral body is somewhat intermediate in shape between modern
> humans and great apes. Additionally, it bears long, cranially and ventrally
> oriented costal (transverse) processes, implying powerful trunk musculature.
> We interpret this combination of features to indicate that A. sediba used its
> lower back in both bipedal and arboreal positional behaviors, as previously
> suggested based on multiple lines of evidence from other parts of the
> skeleton & reconstructed paleobiology of A. sediba. ...
> "... Analysis of the fossils suggested that MH2 would have had an upright
> posture and comfortably walked on two legs, and the curvature of their lower
> back was similar to modern females. However, other aspects of the bones’
> shape suggest that as well as walking, A. sediba probably spent a significant
> amount of time climbing in trees. ...
> Despite the presence of climbing adaptations, A. sediba also demonstrates
> clear evidence for bipedal locomotion. The knee and ankle possess human-like
> adaptations to bipedalism, demonstrating a valgus angle of the femur and a
> human-like ankle joint..."
> "Furthermore, analysis of dental calculus from Malapa Hominin 1 (MH1)
> indicates
> that this individual’s diet was high in C3 plants like fruit and leaves,

So far, no problem.
But then this savanna nonsense, based on 0:

> similar to savannah chimpanzees and Ardipithecus ramidus..."

:-DDD
Only incredible idiots assume their Plio-Pleistocene ancestors ran after antelopes.

Primum Sapienti

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Nov 29, 2021, 1:19:15 AM11/29/21
to
littor...@gmail.com wrote:
>
>> https://elifesciences.org/articles/70447
>
> :-)
> = wading bipedally + climbing arms overhead in swamp forest, as we predicted >20 years ago,
> google our Trends paper "Aquarboreal Ancestors?".

No mention at all swamps.
Based on dental evidence.

>> similar to savannah chimpanzees and Ardipithecus ramidus..."

Based on dental evidence.

:-DDD


> Only incredible idiots assume their Plio-Pleistocene ancestors ran after antelopes.

Only incredible idiots assume their Plio-Pleistocene ancestors had snorkel
noses.

littor...@gmail.com

unread,
Nov 29, 2021, 8:54:08 AM11/29/21
to
Op maandag 29 november 2021 om 07:19:15 UTC+1 schreef Primum Sapienti:

> >> https://elifesciences.org/articles/70447

> > :-)
> > = wading bipedally + climbing arms overhead in swamp forest, as we predicted >20 years ago,
> > google our Trends paper "Aquarboreal Ancestors?".

> >> similar to savannah chimpanzees and Ardipithecus ramidus..."

> Based on dental evidence.

-DDD
Based on wishful thinking.
0 evidence.
Savanna chimps running after antelopes??? :-DDD
The antelope runners become more & more idiotic:
evidence = MH1 had chimp-like diet.

> Only incredible idiots assume their Plio-Pleistocene ancestors had snorkel
> noses.

Only incredible idiots are convinced human noses could not have been used for diving:

OI, BIG NOSE !
New Scientist 2782 p 69 Lastword 16 October 2010

Why do humans evolve external noses that don’t seem to serve any useful purpose – our smelling sensors are inside the head. Our nose is vulnerable to damage, and the majority of primates and other mammals manage with relatively flat faces. Traditional explanations are that the nose protects against dry air, hot air, cold air, dusty air, whatever air, but most savannah mammals have no external noses, and polar animals such as arctic foxes or hares tend to evolve shorter extremities including flatter noses (Allen’s Rule), not larger as the Neanderthal protruding nose.

The answer isn’t so difficult if we simply consider humans like other mammals.

An external nose is seen in elephant seals, hooded seals, tapirs, elephants, swine and, among primates, in the mangrove-dwelling proboscis monkeys. Various, often mutually compatible functions, have been proposed, such as sexual display (in male hooded and elephant seals or proboscis monkeys), manipulation of food (in elephants, tapirs and swine), a snorkel (elephants, proboscis monkeys) and as a nose-closing aid during diving (in most of these animals). These mammals spend a lot of time at the margins of land and water. Possible functions of an external nose in creatures evolving into aquatic ones are obvious and match those listed above in many cases. They can initially act as a nose closure, a snorkel, to keep water out, to dig in wet soil for food, and so on. Afterwards, these external noses can also become co-opted for other functions, such as sexual display (visual as well as auditory) in hooded and elephant seals and proboscis monkeys.

But what does this have to do with human evolution?

The earliest known Homo fossils outside Africa – such as those at Mojokerto in Java and Dmanisi in Georgia – are about 1.8 million years old. The easiest way for them to have spread to other continents, and to islands such as Java, is along the coasts, and from there inland along rivers. During the glacial periods of the Pleistocene – the ice age cycles that ran from about 1.8 million to 12,000 years ago – most coasts were about 100 metres below the present-day sea level, so we don’t know whether or when Homo populations lived there. But coasts and riversides are full of shellfish and other foods that are easily collected and digested by smart, handy and tool-using “apes”, and are rich in potential brain-boosting nutrients such as docosahexaenoic acid (DHA).

If Pleistocene Homo spread along the coasts, beachcombing, wading and diving for seafoods as Polynesian islanders still do, this could explain why Homo erectus evolved larger brains (aided by DHA) and larger noses (because of their part-time diving). This littoral intermezzo could help to explain not only why we like to have our holidays at tropical beaches, eating shrimps and coconuts, but also why we became fat and furless bipeds with long legs, flat feet, large brains and big noses.

Primum Sapienti

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Dec 13, 2021, 1:17:27 AM12/13/21
to
Based on the dental evidence, not just so stories.

> 0 evidence.
> Savanna chimps running after antelopes??? :-DDD
> The antelope runners become more & more idiotic:
> evidence = MH1 had chimp-like diet.
>
>> Only incredible idiots assume their Plio-Pleistocene ancestors had snorkel
>> noses.
>
> Only incredible idiots are convinced human noses could not have been used for diving:

Even dogs can dive... no snorkel noses...

> OI, BIG NOSE !


https://advances.sciencemag.org/content/4/2/eaaq0250.full
Nasalization by Nasalis larvatus: Larger noses audiovisually advertise
conspecifics in proboscis monkeys
Science Advances 21 Feb 2018:

Abstract
Male proboscis monkeys have uniquely enlarged noses that are prominent
adornments, which may have evolved through their sexually competitive
harem group social system. Nevertheless, the ecological roles of the
signals encoded by enlarged noses remain unclear. We found significant
correlations among nose, body, and testis sizes and a clear link between
nose size and number of harem females. Therefore, there is evidence
supporting both male-male competition and female choice as causal factors
in the evolution of enlarged male noses. We also observed that nasal
enlargement systematically modifies the resonance properties of male
vocalizations, which probably encode male quality. Our results indicate
that the audiovisual contributions of enlarged male noses serve as
advertisements to females in their mate selection. This is the first
primate research to evaluate the evolutionary processes involved in
linking morphology, acoustics, and socioecology with unique masculine
characteristics.


https://www.menshealth.com/uk/sex/a36339905/bigger-penis-large-noses/
Men With Larger Noses Have Bigger Penises, According to New Study
Your beak may be giving away more than you think

BY MEN'S HEALTH 05/05/2021
Published in the medical journal Basic and Clinical Andrology, the
researchers of
the study found that men with larger noses had a ‘stretched penile length’
of at
least 5.3 inches, while men with smaller noses had a penis length of 4.1
inches
erect.

The team of researchers drew this conclusion by looking at the dead corpses of
126 men within three days of death and measured different parts of their body.
After taking into account varying factors such height, weight and measurements
of the penis (there were no links between feet size and appendage size, before
you ask), the authors of the study then worked out the "stretched penile
length"
(SPL) of each cadaver. This was measured by, and sorry to be so graphic,
by pulling
the penis up as far as it would go. Hopefully they used gloves.


https://bacandrology.biomedcentral.com/articles/10.1186/s12610-021-00121-z
Nose size indicates maximum penile length

Abstract
Background
In a previous report, we investigated whether the size of male genitalia
similarly
exposed to serum testosterone during aging could change with age and found
that penile length almost stopped increasing during adolescence and decreased
in older males. In this report, to determine what factors other than age
are related
to penile length, we performed a multivariate analysis of the
relationships between
stretched penile length (SPL) and other measurements of genital organs,
nose size,
height and body weight in 126 adults in their 30s–50s.


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