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The hand of Homo naledi
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Pandora
Oct 6, 2015, 4:11:35 PM10/6/15
to
The hand of Homo naledi.
Abstract
A nearly complete right hand of an adult hominin was recovered from
the Rising Star cave system, South Africa. Based on associated hominin
material, the bones of this hand are attributed to Homo naledi. This
hand reveals a long, robust thumb and derived wrist morphology that is
shared with Neandertals and modern humans, and considered adaptive for
intensified manual manipulation. However, the finger bones are longer
and more curved than in most australopiths, indicating frequent use of
the hand during life for strong grasping during locomotor climbing and
suspension. These markedly curved digits in combination with an
otherwise human-like wrist and palm indicate a significant degree of
climbing, despite the derived nature of many aspects of the hand and
other regions of the postcranial skeleton in H. naledi.
http://www.nature.com/ncomms/2015/151006/ncomms9431/full/ncomms9431.html
Pandora
Abstract
A nearly complete right hand of an adult hominin was recovered from
the Rising Star cave system, South Africa. Based on associated hominin
material, the bones of this hand are attributed to Homo naledi. This
hand reveals a long, robust thumb and derived wrist morphology that is
shared with Neandertals and modern humans, and considered adaptive for
intensified manual manipulation. However, the finger bones are longer
and more curved than in most australopiths, indicating frequent use of
the hand during life for strong grasping during locomotor climbing and
suspension. These markedly curved digits in combination with an
otherwise human-like wrist and palm indicate a significant degree of
climbing, despite the derived nature of many aspects of the hand and
other regions of the postcranial skeleton in H. naledi.
http://www.nature.com/ncomms/2015/151006/ncomms9431/full/ncomms9431.html
Pandora
JTEM
Oct 8, 2015, 9:17:25 AM10/8/15
to
It's the linear models here that hurt...
Pandora wrote:
> These markedly curved digits in combination with an
> otherwise human-like wrist and palm indicate a significant degree of
> climbing, despite the derived nature of many aspects of the hand and
> other regions of the postcranial skeleton in H. naledi.
That's linear.
Why not two or more populations? Why not having a species
evolve, radiate out and then each group adapting to it's
own unique environment? Why not having all these different
groups bumping into each other, interbreeding, exchanging
genes JUST ENOUGH to moderate all that adaptation?
Understand?
With MANY gene pools instead of just the one, beneficial
traits are more likely to arise, pop up much more often
than with a single gene pool. And those traits could and
would still be passed along to the other populations.
What is also great about this model is that only the
traits which are beneficial to ALL the populations (or
the most populations) are the ones that everyone is
going to retain & compound. So an arboreal adaption
isn't going to last very long in a coastal population,
regardless of how beneficial it is to the forest
dwellers. But, say, a communications or intelligence
gene might not only be retained by the other populations,
but thanks to all their unique environments they may
actually refine it (evolutionary speaking), carry it to
the next level.
So, the "Multi Regional" model, this "Hybridization"
model seems quite effective, while the 19th century
linear model doesn't so much as effectively explain
WHY evolution would take place, much less how.
-- --
http://jtem.tumblr.com/post/130743017443
Pandora wrote:
> These markedly curved digits in combination with an
> otherwise human-like wrist and palm indicate a significant degree of
> climbing, despite the derived nature of many aspects of the hand and
> other regions of the postcranial skeleton in H. naledi.
Why not two or more populations? Why not having a species
evolve, radiate out and then each group adapting to it's
own unique environment? Why not having all these different
groups bumping into each other, interbreeding, exchanging
genes JUST ENOUGH to moderate all that adaptation?
Understand?
With MANY gene pools instead of just the one, beneficial
traits are more likely to arise, pop up much more often
than with a single gene pool. And those traits could and
would still be passed along to the other populations.
What is also great about this model is that only the
traits which are beneficial to ALL the populations (or
the most populations) are the ones that everyone is
going to retain & compound. So an arboreal adaption
isn't going to last very long in a coastal population,
regardless of how beneficial it is to the forest
dwellers. But, say, a communications or intelligence
gene might not only be retained by the other populations,
but thanks to all their unique environments they may
actually refine it (evolutionary speaking), carry it to
the next level.
So, the "Multi Regional" model, this "Hybridization"
model seems quite effective, while the 19th century
linear model doesn't so much as effectively explain
WHY evolution would take place, much less how.
-- --
http://jtem.tumblr.com/post/130743017443
JTEM
Oct 8, 2015, 9:21:17 AM10/8/15
to
Pandora wrote:
> The hand of Homo naledi.
>
> Abstract
For the record, and in an attempt to get people
> The hand of Homo naledi.
>
> Abstract
to go out on the limb:
I think they're recent. That was my first impression;
that they're WAY younger than has been speculated,
maybe half the age thrown about in the media.
...younger than habilis, younger than erectus.
The 19th century linear model never even occurred
to me. I never once thought that they might be a
"Missing link," that they were an ancestor.
So, yes, that was my immediate impression.
-- --
http://jtem.tumblr.com/post/130743017443
Pandora
Oct 9, 2015, 5:54:32 AM10/9/15
to
On Thu, 8 Oct 2015 06:21:16 -0700 (PDT), JTEM <jte...@gmail.com>
> ...younger than habilis, younger than erectus.
On what basis?
>The 19th century linear model never even occurred
>to me. I never once thought that they might be a
>"Missing link," that they were an ancestor.
>
>So, yes, that was my immediate impression.
Gut feelings are not hypotheses.
Pandora
wrote:
>> The hand of Homo naledi.
>
>> The hand of Homo naledi.
>
>For the record, and in an attempt to get people
>to go out on the limb:
>
>I think they're recent. That was my first impression;
>that they're WAY younger than has been speculated,
>maybe half the age thrown about in the media.
Half of what? What age has been mentioned?
>to go out on the limb:
>
>I think they're recent. That was my first impression;
>that they're WAY younger than has been speculated,
>maybe half the age thrown about in the media.
> ...younger than habilis, younger than erectus.
>The 19th century linear model never even occurred
>to me. I never once thought that they might be a
>"Missing link," that they were an ancestor.
>
>So, yes, that was my immediate impression.
Pandora
crow...@eircom.net
Oct 9, 2015, 2:42:26 PM10/9/15
to
On Thursday, October 8, 2015 at 2:21:17 PM UTC+1, JTEM wrote:
> Pandora wrote:
>
> > The hand of Homo naledi.
> >
> > Abstract
>
> For the record, and in an attempt to get people
> to go out on the limb:
>
> I think they're recent.
The small brain and the range of australopithecine
> Pandora wrote:
>
> > The hand of Homo naledi.
> >
> > Abstract
>
> For the record, and in an attempt to get people
> to go out on the limb:
>
> I think they're recent.
characteristics (including the curved phalanges of the
hand) indicate that these hominids are at the root of
the homo line, and will be dated to around 3 mya.
There is no reason to rule them out from possibly
being ancestral.
Paul
JTEM
Oct 9, 2015, 4:26:54 PM10/9/15
to
Pandora wrote:
> JTEM <jte...@gmail.com> wrote:
> >I think they're recent. That was my first impression;
> >that they're WAY younger than has been speculated,
> >maybe half the age thrown about in the media.
> Half of what? What age has been mentioned?
http://www.dailymail.co.uk/sciencetech/article-3228991/New-species-ancient-human-discovered-Fossilised-remains-15-bodies-unearthed-South-African-cave.html
This is far from the only source claiming 2 million plus.
> > ...younger than habilis, younger than erectus.
> On what basis?
So I speak of IMPRESSIONS and you ask for basis?
A basis for an impression?
There is no basis for any age estimate, bub...
But, in my case, they are exactly the type of
hybrid I would expect, the type that can only
exist AFTER a split, when you've got two or more
very distinct populations.
AND there are many sources that date Australopithecus
to the 1 million year range (a little older).
https://books.google.com/books?id=ystMAgAAQBAJ&pg=PA76&lpg=PA76&dq=south+africa+%22youngest+australopithecus%22+fossil&source=bl&ots=Os_NUqHFZT&sig=r4Vd90doyR0P4z5yMmRrBe_aqp0&hl=en&sa=X&ved=0CB4Q6AEwAGoVChMI4dr8r5u2yAIVi3M-Ch3ckglG#v=onepage&q=south%20africa%20%22youngest%20australopithecus%22%20fossil&f=false
> Gut feelings are not hypotheses.
You're a mindless coward.
Real scientists ALWAYS get impressions, have hunches
and investigate them. They don't cower before usenet
handles and wait for some media source to tell them
what to believe.
This is a discussion group. Discuss, or the hell with
you.
-- --
http://jtem.tumblr.com/post/130831240992
> JTEM <jte...@gmail.com> wrote:
> >I think they're recent. That was my first impression;
> >that they're WAY younger than has been speculated,
> >maybe half the age thrown about in the media.
> Half of what? What age has been mentioned?
This is far from the only source claiming 2 million plus.
> > ...younger than habilis, younger than erectus.
> On what basis?
A basis for an impression?
There is no basis for any age estimate, bub...
But, in my case, they are exactly the type of
hybrid I would expect, the type that can only
exist AFTER a split, when you've got two or more
very distinct populations.
AND there are many sources that date Australopithecus
to the 1 million year range (a little older).
https://books.google.com/books?id=ystMAgAAQBAJ&pg=PA76&lpg=PA76&dq=south+africa+%22youngest+australopithecus%22+fossil&source=bl&ots=Os_NUqHFZT&sig=r4Vd90doyR0P4z5yMmRrBe_aqp0&hl=en&sa=X&ved=0CB4Q6AEwAGoVChMI4dr8r5u2yAIVi3M-Ch3ckglG#v=onepage&q=south%20africa%20%22youngest%20australopithecus%22%20fossil&f=false
> Gut feelings are not hypotheses.
Real scientists ALWAYS get impressions, have hunches
and investigate them. They don't cower before usenet
handles and wait for some media source to tell them
what to believe.
This is a discussion group. Discuss, or the hell with
you.
-- --
http://jtem.tumblr.com/post/130831240992
JTEM
Oct 9, 2015, 4:40:21 PM10/9/15
to
crow...@eircom.net wrote:
> The small brain and the range of australopithecine
> characteristics (including the curved phalanges of the
> hand) indicate that these hominids are at the root of
> the homo line
first of all let me thank you for voicing your impression,
> The small brain and the range of australopithecine
> characteristics (including the curved phalanges of the
> hand) indicate that these hominids are at the root of
> the homo line
even if it's wrong. This is a discussion group, and the
point is to exchange ideas not merely regurgitate something
you once read. Thank you for sharing your ideas. But...
You're wrong. They are vastly more advanced than anything
approximating "The Root."
That's the point.
These look like the very, very LAST of a line, not
the beginning, and the heretofore end of the
australopithecus line was some 2 million years ago,
so this new end has to be WAY after that.
> and will be dated to around 3 mya.
> There is no reason to rule them out from possibly
> being ancestral.
come out, but it's impossible for it to be that old.
It's an australopithecus with lots of very modern
features added, so right there you know it's younger
than what people thought were the last of the
australopithecus line.
-- --
http://jtem.tumblr.com
Pandora
Oct 10, 2015, 7:18:08 AM10/10/15
to
On Fri, 9 Oct 2015 11:42:24 -0700 (PDT), crow...@eircom.net wrote:
>> > The hand of Homo naledi.
>> >
>> > Abstract
>>
>> For the record, and in an attempt to get people
>> to go out on the limb:
>>
>> I think they're recent.
>
>The small brain and the range of australopithecine
>characteristics (including the curved phalanges of the
>hand) indicate that these hominids are at the root of
>the homo line, and will be dated to around 3 mya.
>There is no reason to rule them out from possibly
>being ancestral.
They are more derived than LD 350-1 from Ledi-Geraru at 2.8 Ma,
>> > The hand of Homo naledi.
>> >
>> > Abstract
>>
>> For the record, and in an attempt to get people
>> to go out on the limb:
>>
>> I think they're recent.
>
>The small brain and the range of australopithecine
>characteristics (including the curved phalanges of the
>hand) indicate that these hominids are at the root of
>the homo line, and will be dated to around 3 mya.
>There is no reason to rule them out from possibly
>being ancestral.
currently the oldest specimen assigned to Homo.
They've also been qualified as primitive H. erectus, less derived than
KNM-WT 15000 (Turkana boy) at 1.5 Ma. If the KNM-ER 2598 occipital
fragment also belongs to the derived morph then the age bracket for H.
naledi is ~2.8 - 1.9 Ma.
Note that KNM-ER 1813 (H. habilis) at 1.65 Ma has an endocranial
capacity of 510 cc, well within the range of H. naledi.
Pandora
Pandora
Oct 10, 2015, 7:22:04 AM10/10/15
to
On Fri, 9 Oct 2015 13:26:53 -0700 (PDT), JTEM <jte...@gmail.com>
Homo and Paranthropus, which have been separate clades since at least
2.6 Ma.
>> > ...younger than habilis, younger than erectus.
>
>> On what basis?
>
>So I speak of IMPRESSIONS and you ask for basis?
>
>A basis for an impression?
An impression must be based on an observation, a modicum of data.
Specify, and then perhaps we have something to discuss.
>There is no basis for any age estimate, bub...
>
>But, in my case, they are exactly the type of
>hybrid I would expect, the type that can only
>exist AFTER a split, when you've got two or more
>very distinct populations.
>
>AND there are many sources that date Australopithecus
>to the 1 million year range (a little older).
That opinion dates from the time that everything hominid that wasn't
Homo was lumped into Australopithecus, resulting in a paraphyletic
taxon without much phylogenetic meaning. The former robust
australopithecines that are dated to just over 1 Ma are now considered
to be a highly derived clade of their own, Paranthropus.
>https://books.google.com/books?id=ystMAgAAQBAJ&pg=PA76&lpg=PA76&dq=south+africa+%22youngest+australopithecus%22+fossil&source=bl&ots=Os_NUqHFZT&sig=r4Vd90doyR0P4z5yMmRrBe_aqp0&hl=en&sa=X&ved=0CB4Q6AEwAGoVChMI4dr8r5u2yAIVi3M-Ch3ckglG#v=onepage&q=south%20africa%20%22youngest%20australopithecus%22%20fossil&f=false
>
>> Gut feelings are not hypotheses.
>
>You're a mindless coward.
>
>Real scientists ALWAYS get impressions, have hunches
>and investigate them. They don't cower before usenet
>handles and wait for some media source to tell them
>what to believe.
>
>This is a discussion group. Discuss, or the hell with
>you.
If you can't specify what an impression is based on then it's entirely
subjective and then there's nothing to discuss.
Pandora
wrote:
>> >I think they're recent. That was my first impression;
>> >that they're WAY younger than has been speculated,
>> >maybe half the age thrown about in the media.
>
>> Half of what? What age has been mentioned?
>
>http://www.dailymail.co.uk/sciencetech/article-3228991/New-species-ancient-human-discovered-Fossilised-remains-15-bodies-unearthed-South-African-cave.html
>
>This is far from the only source claiming 2 million plus.
Half of 2.8 Ma equals 1.4 Ma. At that point in time there are only
>> >I think they're recent. That was my first impression;
>> >that they're WAY younger than has been speculated,
>> >maybe half the age thrown about in the media.
>
>> Half of what? What age has been mentioned?
>
>http://www.dailymail.co.uk/sciencetech/article-3228991/New-species-ancient-human-discovered-Fossilised-remains-15-bodies-unearthed-South-African-cave.html
>
>This is far from the only source claiming 2 million plus.
Homo and Paranthropus, which have been separate clades since at least
2.6 Ma.
>> > ...younger than habilis, younger than erectus.
>
>> On what basis?
>
>So I speak of IMPRESSIONS and you ask for basis?
>
>A basis for an impression?
Specify, and then perhaps we have something to discuss.
>There is no basis for any age estimate, bub...
>
>But, in my case, they are exactly the type of
>hybrid I would expect, the type that can only
>exist AFTER a split, when you've got two or more
>very distinct populations.
>
>AND there are many sources that date Australopithecus
>to the 1 million year range (a little older).
Homo was lumped into Australopithecus, resulting in a paraphyletic
taxon without much phylogenetic meaning. The former robust
australopithecines that are dated to just over 1 Ma are now considered
to be a highly derived clade of their own, Paranthropus.
>https://books.google.com/books?id=ystMAgAAQBAJ&pg=PA76&lpg=PA76&dq=south+africa+%22youngest+australopithecus%22+fossil&source=bl&ots=Os_NUqHFZT&sig=r4Vd90doyR0P4z5yMmRrBe_aqp0&hl=en&sa=X&ved=0CB4Q6AEwAGoVChMI4dr8r5u2yAIVi3M-Ch3ckglG#v=onepage&q=south%20africa%20%22youngest%20australopithecus%22%20fossil&f=false
>
>> Gut feelings are not hypotheses.
>
>You're a mindless coward.
>
>Real scientists ALWAYS get impressions, have hunches
>and investigate them. They don't cower before usenet
>handles and wait for some media source to tell them
>what to believe.
>
>This is a discussion group. Discuss, or the hell with
>you.
subjective and then there's nothing to discuss.
Pandora
JTEM
Oct 10, 2015, 2:39:42 PM10/10/15
to
Pandora wrote:
> Half of 2.8 Ma equals 1.4 Ma.
And?
> Half of 2.8 Ma equals 1.4 Ma.
> At that point in time there are only
> Homo and Paranthropus, which have been separate clades since at least
> 2.6 Ma.
talking about a totally new species here -- this claim of
yours that we know everything, that we've already found
all the fossils there are to find would still be wrong, and
not in a subtle way.
> >So I speak of IMPRESSIONS and you ask for basis?
> >
> >A basis for an impression?
> An impression must be based on an observation
thinking. You may share your impressions or not. It's
up to you.
> >AND there are many sources that date Australopithecus
> >to the 1 million year range (a little older).
> That opinion dates from the time that
to go on (and on & on) voicing it. Perhaps something
other than "I think it's old" would be in order here?
> If you can't
You can't. You didn't.
You don't like one cite because of it's age. You
were incapable of demonstrating why it was wrong.
You don't even know enough to read a post BEFORE
responding, so you went off about my stating an
impression without basis even though I did in fact
provide basis.
You're not what you think you are.
-- --
http://jtem.tumblr.com/post/130892432058
garron...@gmail.com
Oct 15, 2015, 11:27:40 PM10/15/15
to
It is interesting that Homo Naledi has started to climb back into the trees.
I believe I came across an hypothesis in, I think, Leakey's "Origins Reconsidered", where the Habilis type of early Homo made a living as a meat thief, stealing the kills of predators such as leopards and others which stored their kills in trees. Having access to stone tools, they would have been able to break the skin of the kills. This might explain "ample fossil evidence indicates H. habilis was a staple in the diet of large predatory animals, such as Dinofelis" (wikipedia.)
This might help explain why Homo Naledi has a hand adapted to using stone tools and also enhanced tree-climbing ability, compared to A'piths.
It would have been important for A'piths and Naledi to sleep in trees, to avoid predators. So being able to climb was more important than for Erectus and Ergaster, who had the mobility to camp away from water sources. However Naledi has even more reason to climb trees, to steal the prey of predators.
I am assuming that Naledi has the short thigh-bone like Habilis and Floresiensis. This means that Naledi is not any sort of distance runner, has to live close to water sources, and as a result is so threatened by predation that sleeping in trees is important.
Anyway, it is a theory I have come across in my pop-science reading, and I thought I would like to see it discussed in this thread.
Peter G.
I believe I came across an hypothesis in, I think, Leakey's "Origins Reconsidered", where the Habilis type of early Homo made a living as a meat thief, stealing the kills of predators such as leopards and others which stored their kills in trees. Having access to stone tools, they would have been able to break the skin of the kills. This might explain "ample fossil evidence indicates H. habilis was a staple in the diet of large predatory animals, such as Dinofelis" (wikipedia.)
This might help explain why Homo Naledi has a hand adapted to using stone tools and also enhanced tree-climbing ability, compared to A'piths.
It would have been important for A'piths and Naledi to sleep in trees, to avoid predators. So being able to climb was more important than for Erectus and Ergaster, who had the mobility to camp away from water sources. However Naledi has even more reason to climb trees, to steal the prey of predators.
I am assuming that Naledi has the short thigh-bone like Habilis and Floresiensis. This means that Naledi is not any sort of distance runner, has to live close to water sources, and as a result is so threatened by predation that sleeping in trees is important.
Anyway, it is a theory I have come across in my pop-science reading, and I thought I would like to see it discussed in this thread.
Peter G.
JTEM
Oct 16, 2015, 1:52:45 AM10/16/15
to
pete...@gmail.com wrote:
> It is interesting that Homo Naledi has started to
> climb back into the trees.
That's a conclusion -- an opinion.
> It is interesting that Homo Naledi has started to
> climb back into the trees.
> This might help explain why Homo Naledi has a hand
> adapted to using stone tools and also enhanced
> tree-climbing ability, compared to A'piths.
The model you advocate here is extremely linear, and
does not match what we find elsewhere albeit much
later (neanderthal, etc). Which is to say, separate
and distinct populations interbreeding.
You get far MORE diversity with such a model -- the
non linear model -- and the potential for infinitely
faster evolution.
"Quantum Leaps," so to speak, are much more feasible.
You would also expect to see some sort of hybridization...
> It would have been important for A'piths and Naledi
> to sleep in trees, to avoid predators.
you just indicated that habilis was a common meal for
predators. Here, I quote you:
: This might explain "ample fossil evidence indicates
: H. habilis was a staple in the diet of large predatory
: animals, such as Dinofelis"
You call habilis a "Staple" in the diet of large
: animals, such as Dinofelis"
predators.
So what does this mean? Well, at the very least it
means that "Avoiding Predators" is NOT as important
as you imply. Other survival strategies could have
applied.
NOTE: Evolution does NOT concern itself with the
individual but the population. Regardless of how
many individuals die, so long as the population is
sustained then evolution has done it's work. This
means that sacrificing the individual for the sake
of the population is a viable strategy.
> I am assuming that Naledi has the short thigh-bone
> like Habilis and Floresiensis. This means that Naledi
> is not any sort of distance runner, has to live close
> to water sources, and as a result is so threatened
> by predation that sleeping in trees is important.
to survival of the POPULATION. And it is the POPULATION,
not the individual, that evolution works on.
> Anyway, it is a theory I have come across in my pop-science
> reading, and I thought I would like to see it discussed in
> this thread.
in many ways quite at odds with the evidence.
How so?
It posits a single breeding population. And this clearly
was never true, not until some time AFTER Homo sapiens
were on the scene... assuming it was ever true then.
Introduce the concept of separate & distinct populations
and the model no longer works. And as all evidence points
to numerous populations OR EVEN SPECIES, I would have to
conclude that we are not dealing with the linear model.
In short: I would suggest that if we are seeing what
looks like a mix of traits, we are looking at a mix
of traits which evolved in parallel within separate
populations, only to later interbreed and hybridize.
-- --
http://jtem.tumblr.com/post/131254848170
garron...@gmail.com
Oct 19, 2015, 5:02:04 AM10/19/15
to
On Friday, October 16, 2015 at 4:52:45 PM UTC+11, JTEM wrote:
> pete...@gmail.com wrote:
>
> > It is interesting that Homo Naledi has started to
> > climb back into the trees.
>
> That's a conclusion -- an opinion.
Well the OP says: "However, the finger bones are longer
> pete...@gmail.com wrote:
>
> > It is interesting that Homo Naledi has started to
> > climb back into the trees.
>
> That's a conclusion -- an opinion.
and more curved than in most australopiths, indicating frequent use of
the hand during life for strong grasping during locomotor climbing and
suspension."
I assume the OP meant locomotor climbing and suspension in trees. I doubt any other sort of climbing was inferred. So in this thread, a return to the trees can be perhaps taken as a fact to be explained.
the hand during life for strong grasping during locomotor climbing and
suspension."
> The model you advocate here is extremely linear, and
> does not match what we find elsewhere albeit much
> later (neanderthal, etc). Which is to say, separate
> and distinct populations interbreeding.
>
> You get far MORE diversity with such a model -- the
> non linear model -- and the potential for infinitely
> faster evolution.
> > It would have been important for A'piths and Naledi
> > to sleep in trees, to avoid predators.
>
> Not just extremely doubtful, but rather inexplicable as
> you just indicated that habilis was a common meal for
> predators. Here, I quote you:
>
> : This might explain "ample fossil evidence indicates
> : H. habilis was a staple in the diet of large predatory
> : animals, such as Dinofelis"
>
> You call habilis a "Staple" in the diet of large
> predators.
>
> So what does this mean? Well, at the very least it
> means that "Avoiding Predators" is NOT as important
> as you imply. Other survival strategies could have
> applied.
>
> NOTE: Evolution does NOT concern itself with the
> individual but the population. Regardless of how
> many individuals die, so long as the population is
> sustained then evolution has done it's work. This
> means that sacrificing the individual for the sake
> of the population is a viable strategy.
Regarding sleeping in trees, I am unsure what you find "inexplicable". Chimpanzees and gorillas sleep in trees. I assume they do this to avoid predators. Since A'piths and especially Naladi appear to have hands and feet adapted to climbing, and they appear to have lived in environments where there were at least some trees, it is plausible that they did so. There might be other reasons for tree climbing ability, such as access to fruit. However since a'piths, Habilis, and Erectus would all like some fruit no doubt, then it is difficult to differentiate between them.
I do not see how you can simply dismiss predator pressure out of hand as an evolutionary factor, especially in the face of fossil evidence of its occurrence. It is obvious to link climbing ability with predator pressure and sleeping in trees, the need to sleep near water for the daily drink, or the ability to camp at a safe distance.
>
> > I am assuming that Naledi has the short thigh-bone
> > like Habilis and Floresiensis. This means that Naledi
> > is not any sort of distance runner, has to live close
> > to water sources, and as a result is so threatened
> > by predation that sleeping in trees is important.
>
> Or, just like habilis, it wasn't important at all, not
> to survival of the POPULATION. And it is the POPULATION,
> not the individual, that evolution works on.
>
> > Anyway, it is a theory I have come across in my pop-science
> > reading, and I thought I would like to see it discussed in
> > this thread.
>
> It strikes me as very old fashioned, very linear, and
> in many ways quite at odds with the evidence.
>
> How so?
>
> It posits a single breeding population. And this clearly
> was never true, not until some time AFTER Homo sapiens
> were on the scene... assuming it was ever true then.
>
> Introduce the concept of separate & distinct populations
> and the model no longer works. And as all evidence points
> to numerous populations OR EVEN SPECIES, I would have to
> conclude that we are not dealing with the linear model.
>
> In short: I would suggest that if we are seeing what
> looks like a mix of traits, we are looking at a mix
> of traits which evolved in parallel within separate
> populations, only to later interbreed and hybridize.
>
>
>
If one creature such as Habilis has short thigh bones and hands and feet somewhat adapted to a climbing existence, and the other creature such as Erectus has long thigh bones with non-climbing hands and feet, then I would find it difficult to accept that they were the same species, irrespective of whether Sapiens and Neanderthals could interbreed.
Saying that early Homo was all one variable species does not provide any explanations about oddities such as this climbing ability evident in the OP.
I would concede that the variation in other skeletal features does make an unclear evolutionary picture.
JTEM
Oct 19, 2015, 3:23:28 PM10/19/15
to
pete...@gmail.com wrote:
> Well the OP says:
You're not thinking, you're YIELDING your brain to
a cherry picked authority.
Again: You're quoting AN OPINION, not a fact. It's
not even a good opinion!
> "However, the finger bones are longer
> and more curved than in most australopiths, indicating frequent use of
> the hand during life for strong grasping during locomotor climbing and
> suspension."
Great. And the feet suggests a habitual upright walker
on our (modern) level.
Thus, what it looks like is a hybrid. Why not call it a
hybrid?
> So in this thread, a return to the trees can be perhaps
> taken as a fact to be explained.
Which is completely the opposite of the FACTS surrounding
the feet.
> I would assume that Sapiens and Neanderthals have much
> the same body plan and ecological niche, being biological
> races of a species temporarily separated due to climate
> change. I doubt the same can be said for Habilis and Erectus.
So you're arguing that erectus did NOT evolve from
habilis? Because if habilis is an ancestor, they
were EXACTLY related to erectus as neanderthals were
to so-called "moderns," only habilis was eventually
so further separated that the two split into different
species.
Put another way:
Modern Europeans/Asians/Africans are exactly as
distantly related as habilis was at one time from
erectus. But as time went on habilis & erectus
grew even further apart, eventually fully breaking
into distinct species.
Now it could be that time isn't the biggest factor,
that environmental changes were the major driver here,
but the model is the same. They started as one population,
split into two or more and eventually grew so different
they separate species.
> With respect to the "staple" quote, I was quoting the
> wikipedia article on Homo Habilis which states the words
> quoted regarding Habilis being a staple of Dinofelis. I
> assume from the wording that there is more evidence that
> Habilis was preyed upon than for A'piths.
Which, if true, if it's not an artifact of preservation,
could mean any number of things.
> Regarding sleeping in trees, I am unsure what you find "inexplicable".
You're way off base here. It's that linear thinking...
Chimpanzees evolved from an upright walking tool user. The
molecular distance doesn't seem to allow for anything else.
And even the "Molecular Clocks," which are uniformly too
old, place the LCA well within the range of australopithecus,
suggesting (to me at least) that it was likely a later and
not an early australopithecus population.
The question here is what mechanism forces an upright
walking australopithecus off the ground and into the
trees? Linear models as those you propose can't work.
> Chimpanzees and gorillas sleep in trees.
And humans don't and horses don't. But humans & horses
did not evolve in the same place at the same time,
responding to the same pressures. Neither did chimps
and gorillas.
> I assume they do this to avoid predators.
Quite frankly, in the case of chimps, I assume it's
to avoid humans.
> Since A'piths and especially Naladi appear to have
> hands and feet adapted to climbing
Completely wrong. The foot of naledi is very human like.
It's not a human foot, it's not going to fool the
experts, but it's CLOSER to us humans than pretty any
of their kin:
: ...They show the H. naledi foot shares many features
: with a modern human foot, indicating it is well-adapted
: for standing and walking on two feet.
http://phys.org/news/2015-10-foot-homo-naledi.html
> I do not see how you can simply dismiss predator pressure
> out of hand as an evolutionary factor
Why do you pretend that humans are not a predator?
-- --
http://jtem.tumblr.com/post/131254848170
> Well the OP says:
You're not thinking, you're YIELDING your brain to
a cherry picked authority.
Again: You're quoting AN OPINION, not a fact. It's
not even a good opinion!
> "However, the finger bones are longer
> and more curved than in most australopiths, indicating frequent use of
> the hand during life for strong grasping during locomotor climbing and
> suspension."
on our (modern) level.
Thus, what it looks like is a hybrid. Why not call it a
hybrid?
> So in this thread, a return to the trees can be perhaps
> taken as a fact to be explained.
the feet.
> I would assume that Sapiens and Neanderthals have much
> the same body plan and ecological niche, being biological
> races of a species temporarily separated due to climate
> change. I doubt the same can be said for Habilis and Erectus.
habilis? Because if habilis is an ancestor, they
were EXACTLY related to erectus as neanderthals were
to so-called "moderns," only habilis was eventually
so further separated that the two split into different
species.
Put another way:
Modern Europeans/Asians/Africans are exactly as
distantly related as habilis was at one time from
erectus. But as time went on habilis & erectus
grew even further apart, eventually fully breaking
into distinct species.
Now it could be that time isn't the biggest factor,
that environmental changes were the major driver here,
but the model is the same. They started as one population,
split into two or more and eventually grew so different
they separate species.
> With respect to the "staple" quote, I was quoting the
> wikipedia article on Homo Habilis which states the words
> quoted regarding Habilis being a staple of Dinofelis. I
> assume from the wording that there is more evidence that
> Habilis was preyed upon than for A'piths.
could mean any number of things.
> Regarding sleeping in trees, I am unsure what you find "inexplicable".
Chimpanzees evolved from an upright walking tool user. The
molecular distance doesn't seem to allow for anything else.
And even the "Molecular Clocks," which are uniformly too
old, place the LCA well within the range of australopithecus,
suggesting (to me at least) that it was likely a later and
not an early australopithecus population.
The question here is what mechanism forces an upright
walking australopithecus off the ground and into the
trees? Linear models as those you propose can't work.
> Chimpanzees and gorillas sleep in trees.
did not evolve in the same place at the same time,
responding to the same pressures. Neither did chimps
and gorillas.
> I assume they do this to avoid predators.
to avoid humans.
> Since A'piths and especially Naladi appear to have
> hands and feet adapted to climbing
It's not a human foot, it's not going to fool the
experts, but it's CLOSER to us humans than pretty any
of their kin:
: ...They show the H. naledi foot shares many features
: with a modern human foot, indicating it is well-adapted
: for standing and walking on two feet.
http://phys.org/news/2015-10-foot-homo-naledi.html
> I do not see how you can simply dismiss predator pressure
> out of hand as an evolutionary factor
-- --
http://jtem.tumblr.com/post/131254848170
m_ver...@skynet.be
Dec 11, 2015, 5:42:05 PM12/11/15
to
Long thumbs are primitive: humans kept long thums, and apes reduced thumb length (Homo>Gorilla>Pan>Pongo): naledi's long thumbs are no indication naledi should be placed without Homo. The curved hand-bones indicate vertical climbing in the branches above the swamp (fossilisation in mud-stone = stagnant water). The flat forefeet suggest frequent surface-swimming-wading in wetlands, in search for waterlilies, sedges, frogbit & other aquatic herbaceous vegetation (cf dentition), like bonobo so, but more frequently (google bonobo wading).
researchGate marc verhaegen
> The hand of Homo naledi.
researchGate marc verhaegen
> The hand of Homo naledi.
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