A *Dry* Discussion About The Origin Of Bipedalism

[Rmacfarl]

Mclark,

I'm interested in this idea you've previously floated about
the origin of bipedalism being linked to arboreal origins. I
know it's been brought up usually in opposition to all that
wet theorising, but I'd like to hear you expound on your idea
bit further. Care to have a crack?

[Watery types need not apply...]

Ross Macfarlane

[Jim McGinn]

rmacfarl wrote:
> Mclark,
>
> I'm interested in this idea you've previously floated about
> the origin of bipedalism being linked to arboreal origins. I
> know it's been brought up usually in opposition to all that
> wet theorising, but I'd like to hear you expound on your
> idea bit further. Care to have a crack?
>
> [Watery types need not apply...]
>
> Ross Macfarlane

Clark, expound? Good luck with that. As with previous
expositions by Clark you can expect it to achieve the height
of vagueness.

Classic Misassumptions of the Origins of Bipedalism:

1) Myth: It provided a locomotory advantage; speed or
efficiency.

Fact: It was a locomotory compromise. Bipedal apes are much
slower, and if more efficient at all it is so slight as to be
not worth considering.

2) Myth: Since bipedalism took place during a period of
climatic drying and subsequent thinning of forest its
emergence must be associated with travelling the distance
between stands of forest to gain access to finite
resources.

Fact: There is more than one strategy to deal with resource
shortage. Many of the other species to whom with which they
competed directly for finite food resources (especially during
the dry season) employed migration to gain access to finite
resources. These animals were quadrupedal (or they flew).
About the last thing we'd expect from a species that assumed
such strategies would be a shift to bipedalism. It simply
makes more sense to assume that our ancestors assumed a
strategy that involved territorialism and communalism rather
than migration--especially considering that communalism and
territorialism are consistent with what we see in ourselves
currently.

This opens the question as to how bipedalism enables or
facilitates communal territorialism. (The answers are
contained in my Ecological Gatekeeper Hypothesis.)

3) Myth: The freeing of the hands that bipedalism enabled in
our earliest chimpanzee-like ancestors might have enabled
the use of weapons or tools to achieve hunting or
scavenging.

Fact: These earliest hominids were millions of years away from
having the intellect, cooperative behaviors, and manipulative
abilities necessary to for such a diminutive creature to have
competed with the large agressive social hunters and
scavengers that are evident in the fossil record of east
Africa beginning in the middle miocene, about 8 mya.
(Moreover, only in the context of a scenario that involves
communalism could we ever expect them to evolve such
intellectual and cooperative abilities.)

Jim

[Jim McGinn]

Paul Crowley wrote:
> "Jim McGinn" <jimmcginn@yahoo.com> wrote in message news:11-
> 25126302.708791.228780@f14g2000cwb.googlegroups.com...
>
> > Classic Misassumptions of the Origins of Bipedalism:
> >
> > 1) Myth: It provided a locomotory advantage; speed or
> > efficiency.
> >
> > Fact: It was a locomotory compromise.
>
> A compromise between what and what?

Freeing of hands for other uses (obviously). See my hypothesis
for more details.

> Oh, I know the answer: you haven't a clue. You're just
> making it up as you go along.

Shut-up dimwit.

>
> > Bipedal apes are much slower, and if more efficient at all
> > it is so slight as to be not worth considering.
>
> Agreed. But bipedalism was an ENORMOUS change, and it had
> a cause.

No duh. (All evolutionary changes have a cause.)

>
> > 2) Myth: Since bipedalism took place during a period of
> > climatic drying and subsequent thinning of forest
>
> It didn't.

Fossil evidence proves that the middle to late miocene was
drier than that that proceeded it. This is old news.

The statement is inherently
> nonsensical. The timescales are up the spout.

Read between the lines, dumbass.

> You might as well say that the presidency of
> G.W. Bush took place during a rainstorm. Bipedalism would
> have taken at least 50 kyr to evolve, and probably much
> longer. Episodes of drying (and forest-thinning) are
> much shorter and more variable.

Let the evidence be your guide.

Paul, as usual you want to argue about semantics. Facts are
facts. Get with it.

>
> > 3) Myth: The freeing of the hands that bipedalism enabled
> > in our earliest chimpanzee-like ancestors might have
> > enabled the use of weapons or tools to achieve hunting
> > or scavenging.
> >
> > Fact: These earliest hominids were millions of years away
> > from having the intellect, cooperative behaviors, and
> > manipulative abilities necessary to for such a diminutive
> > creature to have competed with the large agressive social
> > hunters and scavengers that are evident in the fossil
> > record of east Africa beginning in the middle miocene,
> > about 8 mya.
>
> They did somehow, at some point, manage to cope with such
> animals.

Agreed. 3mya at earliest.

They didn't learn
> how to do by avoiding them, or by delaying the contact.

Agreed. My hypothesis indicates constant opposition
starting at 8 mya.

We just have to work out how
> -- and it's not too difficult.

I agree. And I have.

But bipedalism
> came about for an enormously important reason -- and that
> could only have been the 'freeing of the hands'.

On this point we certainly agree.

Jim

[Paul Crowl]

"Jim McGinn" <jimmcginn@yahoo.com> wrote in message
news:1125126302.708791.228780@f14g2000cwb.googlegroups.com...

> Classic Misassumptions of the Origins of Bipedalism:
>
> 1) Myth: It provided a locomotory advantage; speed or
> efficiency.
>
> Fact: It was a locomotory compromise.

A compromise between what and what? Oh, I know the answer: you
haven't a clue. You're just making it up as you go along.

> Bipedal apes are much slower, and if more efficient at all
> it is so slight as to be not worth considering.

Agreed. But bipedalism was an ENORMOUS change, and it
had a cause.

> 2) Myth: Since bipedalism took place during a period of
> climatic drying and subsequent thinning of forest

It didn't. The statement is inherently nonsensical. The
timescales are up the spout. You might as well say that the
presidency of
G.W. Bush took place during a rainstorm. Bipedalism would have
taken at least 50 kyr to evolve, and probably much
longer. Episodes of drying (and forest-thinning) are much
shorter and more variable.

> 3) Myth: The freeing of the hands that bipedalism enabled in
> our earliest chimpanzee-like ancestors might have enabled
> the use of weapons or tools to achieve hunting or
> scavenging.
>
> Fact: These earliest hominids were millions of years away
> from having the intellect, cooperative behaviors, and
> manipulative abilities necessary to for such a diminutive
> creature to have competed with the large agressive social
> hunters and scavengers that are evident in the fossil record
> of east Africa beginning in the middle miocene, about 8 mya.

They did somehow, at some point, manage to cope with such
animals. They didn't learn how to do by avoiding them, or by
delaying the contact. We just have to work out how -- and it's
not too difficult. But bipedalism came about for an enormously
important reason -- and that could only have been the 'freeing
of the hands'.

Paul.

[McLark]

"rmacfarl" <rmacfarl@alphalink.com.au> wrote in message
news:1125114048.973601.63410@f14g2000cwb.googlegroups.com...
> Mclark,
>
> I'm interested in this idea you've previously floated about
> the origin of bipedalism being linked to arboreal origins. I
> know it's been brought up usually in opposition to all that
> wet theorising, but I'd like to hear you expound on your
> idea bit further. Care to have a crack?

Well, if you ask me, I think this whole 90% twist from
horizontal to vertical is a response to the problem of moving
an increasingly large body through the branches of trees. I
think I had this conversation with Pauline a while back and if
I recall (without a search), I think that I said something
about the nature of trees (they have a vertical trunk, in most
cases, branches angle off from this trunk at increasing angles
as they move away from the trunk and that useful resources are
usually found toward the termination of these branches), and
that larger bodies would be restricted by certain physical
laws from employing the normal monkey modes of travel. As
these increasingly large apes were restricted toward the
center of the tree, they were increasingly relegated to
vertical climbing (the vertical trunk), prevented from
brachiating (more central branches are larger). That leaves
them with the upper surfaces of larger branches. Foraging, and
supplementing their balance with their hands by grasping
nearby branches, these apes would find themselves with their
feet both *on the ground* and acting as the sole interface
with the substrate. Add this to the fact that running along
the tops of branches is actually *more* stable that walking,
and the observation that *sitting* adds its own set of
variables to the mix (changes to the lower spine) and you have
a certain inevitability to the notion that those apes thus
pre-adapted to bipedalism would find themselves moving
bipedally when ~whatever~ moved them to the ground. "Whatever"
could be anything that would initiate the move from tree to
terrestrial -- drying and cooling, which would disperse the
trees, a mere local preference for a food source on the
ground, a population shift in geography, etc.

I think R.H Crompton has at least intimated much the same.
Check this out: http://www.liv.ac.uk/premog/premog-pubs.htm

> [Watery types need not apply...]
>
> Ross Macfarlane

[Jim McGinn]

mclark wrote:
> "rmacfarl" <rmacfarl@alphalink.com.au> wrote in message new-
> s:1125114048.973601.63410@f14g2000cwb.googlegroups.com...
> > Mclark,
> >
> > I'm interested in this idea you've previously floated
> > about the origin of bipedalism being linked to arboreal
> > origins. I know it's been brought up usually in opposition
> > to all that wet theorising, but I'd like to hear you
> > expound on your idea bit further. Care to have a crack?
>
> Well, if you ask me, I think this whole 90% twist

90%? Twist?

from
> horizontal to vertical is a response to the problem of
> moving an increasingly large body through the branches of
> trees. I think I had this conversation with Pauline a while
> back and if I recall (without a search), I think that I said
> something about the nature of trees (they have a vertical
> trunk, in most cases, branches angle off from this trunk at
> increasing angles as they move away from the trunk and that
> useful resources are usually found toward the termination of
> these branches), and that larger bodies would be restricted
> by certain physical laws

Uh, gravity?

from employing the normal monkey modes of travel.
> As these increasingly large apes were restricted toward the
> center of the tree, they were increasingly relegated to
> vertical climbing (the vertical trunk), prevented from
> brachiating (more central branches are larger). That leaves
> them with the upper surfaces of larger branches. Foraging,
> and supplementing their balance with their hands by grasping
> nearby branches, these apes would find themselves with their
> feet both *on the ground* and acting as the sole interface
> with the substrate. Add this to the fact that running along
> the tops of branches is actually *more* stable that walking,
> and the observation that *sitting* adds its own set of
> variables to the mix (changes to the lower spine) and you
> have a certain inevitability to the notion that those apes
> thus pre-adapted to bipedalism would find themselves moving
> bipedally when ~whatever~

Whatever?

moved them to the ground. "Whatever" could be
> anything that would initiate the move from tree to
> terrestrial --

Amazing.

> drying and cooling, which would disperse the trees, a mere
> local preference for a food source on the ground, a
> population shift in geography, etc.
>
> I think R.H Crompton has at least intimated much the same.
> Check this out: http://www.liv.ac.uk/premog/premog-pubs.htm
>
> > [Watery types need not apply...]
> >
> > Ross Macfarlane
> >

You make Algis look like a genius in comparison.

Jim

[Rmacfarl]

mclark wrote:
> "rmacfarl" <rmacfarl@alphalink.com.au> wrote in message new-
> s:1125114048.973601.63410@f14g2000cwb.googlegroups.com...
> > Mclark,
> >
> > I'm interested in this idea you've previously floated
> > about the origin of bipedalism being linked to arboreal
> > origins. I know it's been brought up usually in opposition
> > to all that wet theorising, but I'd like to hear you
> > expound on your idea bit further. Care to have a crack?
>
> Well, if you ask me, I think this whole 90% twist from
> horizontal to vertical is a response to the problem of
> moving an increasingly large body through the branches of
> trees. I think I had this conversation with Pauline a while
> back and if I recall (without a search), I think that I said
> something about the nature of trees (they have a vertical
> trunk, in most cases, branches angle off from this trunk at
> increasing angles as they move away from the trunk and that
> useful resources are usually found toward the termination of
> these branches), and that larger bodies would be restricted
> by certain physical laws from employing the normal monkey
> modes of travel. As these increasingly large apes were
> restricted toward the center of the tree, they were
> increasingly relegated to vertical climbing (the vertical
> trunk), prevented from brachiating (more central branches
> are larger). That leaves them with the upper surfaces of
> larger branches. Foraging, and supplementing their balance
> with their hands by grasping nearby branches, these apes
> would find themselves with their feet both *on the ground*
> and acting as the sole interface with the substrate. Add
> this to the fact that running along the tops of branches is
> actually *more* stable that walking, and the observation
> that *sitting* adds its own set of variables to the mix
> (changes to the lower spine) and you have a certain
> inevitability to the notion that those apes thus pre-adapted
> to bipedalism would find themselves moving bipedally when
> ~whatever~ moved them to the ground.

Hmm [grimace]. My experience of climbing is that when you have
to try to get out to the further edges of a thin branch, the
opposite to what you posit above applies. I prefer to get on
all fours & grip on to the branch with my legs while I
gingerly stretch out along a section that feels like it's
about to give way under me.

What I've seen of chimps suggest a similar approach. I have a
mental image of males hunting by climbing outward on all fours
toward a trapped monkey, for example.

Also of course, the actual brachiating ape adaption is for
suspense foraging - hanging under branch, cf. orangutans, as
opposed to Old World monkeys that run on all fours along the
top of branches.

All in all when you're up in the treetops I'd feel more secure
with 3 or 4 points of contact when branch-walking than with 1
or 2. Hence I can't say I find this scenario convincing.

Just my opinion, of course.

> "Whatever" could be anything that would initiate the move
> from tree to terrestrial -- drying and cooling, which would
> disperse the trees, a mere local preference for a food
> source on the ground, a population shift in geography, etc.
>
> I think R.H Crompton has at least intimated much the same.
> Check this out: http://www.liv.ac.uk/premog/premog-pubs.htm

Which of the papers was the specific comment in, do you
recall?

>
> > [Watery types need not apply...]

Nor other loons - i.e. Jimbo & Paulie...

Ross Macfarlane

[Jim McGinn]

rmacfarl wrote:
> mclark wrote:
> > "rmacfarl" <rmacfarl@alphalink.com.au> wrote in message
> > news:1125114048.973601.63410@f14g2000cwb.googlegroups.-
> > com...
> > > Mclark,
> > >
> > > I'm interested in this idea you've previously floated
> > > about the origin of bipedalism being linked to arboreal
> > > origins. I know it's been brought up usually in
> > > opposition to all that wet theorising, but I'd like to
> > > hear you expound on your idea bit further. Care to have
> > > a crack?
> >
> > Well, if you ask me, I think this whole 90% twist from
> > horizontal to vertical is a response to the problem of
> > moving an increasingly large body through the branches of
> > trees. I think I had this conversation with Pauline a
> > while back and if I recall (without a search), I think
> > that I said something about the nature of trees (they have
> > a vertical trunk, in most cases, branches angle off from
> > this trunk at increasing angles as they move away from the
> > trunk and that useful resources are usually found toward
> > the termination of these branches), and that larger bodies
> > would be restricted by certain physical laws from
> > employing the normal monkey modes of travel. As these
> > increasingly large apes were restricted toward the center
> > of the tree, they were increasingly relegated to vertical
> > climbing (the vertical trunk), prevented from brachiating
> > (more central branches are larger). That leaves them with
> > the upper surfaces of larger branches. Foraging, and
> > supplementing their balance with their hands by grasping
> > nearby branches, these apes would find themselves with
> > their feet both *on the ground* and acting as the sole
> > interface with the substrate. Add this to the fact that
> > running along the tops of branches is actually *more*
> > stable that walking, and the observation that *sitting*
> > adds its own set of variables to the mix (changes to the
> > lower spine) and you have a certain inevitability to the
> > notion that those apes thus pre-adapted to bipedalism
> > would find themselves moving bipedally when ~whatever~
> > moved them to the ground.
>
> Hmm [grimace]. My experience of climbing is that when you
> have to try to get out to the further edges of a thin
> branch, the opposite to what you posit above applies. I
> prefer to get on all fours & grip on to the branch with my
> legs while I gingerly stretch out along a section that feels
> like it's about to give way under me.

What are your primary references for this?

>
> What I've seen of chimps suggest a similar approach. I have
> a mental image of males hunting by climbing outward on all
> fours toward a trapped monkey, for example.

You have to be retarded to think this has any relevance to
hominid evolution.

>
> Also of course, the actual brachiating ape adaption is for
> suspense foraging - hanging under branch, cf. orangutans, as
> opposed to Old World monkeys that run on all fours along the
> top of branches.
>
> All in all when you're up in the treetops I'd feel more
> secure with 3 or 4 points of contact when branch-walking
> than with 1 or 2. Hence I can't say I find this scenario
> convincing.
>
> Just my opinion, of course.

Anthrodimwit

>
> > "Whatever" could be anything that would initiate the move
> > from tree to terrestrial -- drying and cooling, which
> > would disperse the trees, a mere local preference for a
> > food source on the ground, a population shift in
> > geography, etc.
> >
> > I think R.H Crompton has at least intimated much the same.
> > Check this out:
> > http://www.liv.ac.uk/premog/premog-pubs.htm
>
> Which of the papers was the specific comment in, do
> you recall?

Like it matters.

>
> >
> > > [Watery types need not apply...]
>
> Nor other loons - i.e. Jimbo & Paulie...
>
> Ross Macfarlane

[McLark]

"rmacfarl" <rmacfarl@alphalink.com.au> wrote in message
news:1125301280.342279.221630@g44g2000cwa.googlegroups.com...
>
> mclark wrote:
>> "rmacfarl" <rmacfarl@alphalink.com.au> wrote in message ne-
>> ws:1125114048.973601.63410@f14g2000cwb.googlegroups.com...
>> > Mclark,
>> >
>> > I'm interested in this idea you've previously floated
>> > about the origin of bipedalism being linked to arboreal
>> > origins. I know it's been brought up usually in
>> > opposition to all that wet theorising, but I'd like to
>> > hear you expound on your idea bit further. Care to have a
>> > crack?
>>
>> Well, if you ask me, I think this whole 90% twist from
>> horizontal to vertical is a response to the problem of
>> moving an increasingly large body through the branches of
>> trees. I think I had this conversation with Pauline a while
>> back and if I recall (without a search), I think that I
>> said something about the nature of trees (they have a
>> vertical trunk, in most cases, branches angle off from this
>> trunk at increasing angles as they move away from the trunk
>> and that useful resources are usually found toward the
>> termination of these branches), and that larger bodies
>> would be restricted by certain physical laws from employing
>> the normal monkey modes of travel. As these increasingly
>> large apes were restricted toward the center of the tree,
>> they were increasingly relegated to vertical climbing (the
>> vertical trunk), prevented from brachiating (more central
>> branches are larger). That leaves them with the upper
>> surfaces of larger branches. Foraging, and supplementing
>> their balance with their hands by grasping nearby branches,
>> these apes would find themselves with their feet both *on
>> the ground* and acting as the sole interface with the
>> substrate. Add this to the fact that running along the tops
>> of branches is actually *more* stable that walking, and the
>> observation that *sitting* adds its own set of variables to
>> the mix (changes to the lower spine) and you have a certain
>> inevitability to the notion that those apes thus
>> pre-adapted to bipedalism would find themselves moving
>> bipedally when ~whatever~ moved them to the ground.
>
> Hmm [grimace]. My experience of climbing is that when you
> have to try to get out to the further edges of a thin
> branch, the opposite to what you posit above applies. I
> prefer to get on all fours & grip on to the branch with my
> legs while I gingerly stretch out along a section that feels
> like it's about to give way under me.
>
> What I've seen of chimps suggest a similar approach. I have
> a mental image of males hunting by climbing outward on all
> fours toward a trapped monkey, for example.
>
> Also of course, the actual brachiating ape adaption is for
> suspense foraging - hanging under branch, cf. orangutans, as
> opposed to Old World monkeys that run on all fours along the
> top of branches.
>
> All in all when you're up in the treetops I'd feel more
> secure with 3 or 4 points of contact when branch-walking
> than with 1 or 2. Hence I can't say I find this scenario
> convincing.

Which was my point, of course. Those 3 or 4 points of contact
are not necessarily the same branch. I can be standing on the
branch below me and support my large mass by bracing against
other nearby branches. Moving out to the periphery of the tree
in pursuit of either the monkeys or the foods they eat is a
dicey proposition. Monkeys know this and react to hunting
groups of chimps by retreating to the smaller branches. Chimps
counter this by hunting in groups. They know that they will be
hard pressed to follow a monkey from one tree to the next so
they position various of their fellows in the adjacent trees
and "herd" the unfortunate monkey from one expectant hunter to
the next. In the resulting confusion, amidst all the screaming
and hollering, the monkey is caught while trying to escape
--by some chimp strategically placed on a large branch.

I know the difficulty. The problem, as I see it, is how you
get an otherwise four-footed primate to stand up whilst
engaged in the normal, everyday activities of a quadruped. It
*may* be that these adjustments are the result of increasing
body size --which may be a reaction to something else (like
scarce resources or sexual politics). Increasing body size
then introduces all these other difficulties --how to move
efficiently in an environment with shrinking possibilities. If
you're restricted to the larger branches, you would be
restricted in your adaptive responses. Once you have a
*climbing* orthograde ape, moving it to the ground becomes a
natural progression. Figuring out what drove this move is
another difficulty hinted at previously. Were they pushed,
pulled, what? Did they leave because the trees dropped out
from under them or were they drawn away by the promise of more
lucrative jobs in the city? I think that it is pretty well
established that at some point our ancestors were *living* in
trees. We now live on the ground. The first ground personnal
were large-bodied, obligate bipeds. The seeds of that
bipedalism *must* have been nurtured in the trees. The
question is how.

> Just my opinion, of course.

And merely mine.

>> "Whatever" could be anything that would initiate the move
>> from tree to terrestrial -- drying and cooling, which would
>> disperse the trees, a mere local preference for a food
>> source on the ground, a population shift in geography, etc.
>>
>> I think R.H Crompton has at least intimated much the same.
>> Check this out: http://www.liv.ac.uk/premog/premog-pubs.htm
>
> Which of the papers was the specific comment in, do
> you recall?

No, I don't. I only know that Crompton has said much the same.
It wouldn't hurt to read what he has to say about the
mechanics involved.

Here is another one. Though slightly quirky, there are a few
gems scattered throughout:

http://www.alexandertechnique.be/English/sit_happens.htm

[..]
> Ross Macfarlane
--
"You might be right but, people shouldn't buy it unless you
can *demonstrate* it through logical reasoning and/or
evidence and I just don't think you have done that." ---Algis
Kuliukas 08/14/05

[Paul Crowl]

"mclark" <biteme@spammer.com> wrote in message
news:enCQe.36627$32.18943@tornado.rdc-kc.rr.com...

> >> Well, if you ask me, I think this whole 90% twist from
> >> horizontal to vertical is a response to the problem of
> >> moving an increasingly large body through the branches of
> >> trees. I think I had this conversation with Pauline a
> >> while back and if I recall (without a search), I think
> >> that I said something about the nature of trees (they
> >> have a vertical trunk, in most cases, branches angle off
> >> from this trunk at increasing angles as they move away
> >> from the trunk and that useful resources are usually
> >> found toward the termination of these branches), and that
> >> larger bodies would be restricted by certain physical
> >> laws from employing the normal monkey modes of travel.

This is another wonderful example of Mikey trying to think.
On the one hand, you want to cheer, and yell encouragement;
on the other, you have to cringe with embarrassment and
grimace with pain. It's somewhere between seeing a
one-year-old taking his first steps and your mother (who's
enormously fat) being on stage trying to sing, when she
hasn't a note of music in any bone.

> >> Add this to the fact that running along the tops of
> >> branches is actually *more* stable that walking, and the
> >> observation that *sitting* adds its own set of variables
> >> to the mix (changes to the lower spine) and you have a
> >> certain inevitability to the notion that those apes thus
> >> pre-adapted to bipedalism would find themselves moving
> >> bipedally when ~whatever~ moved them to the ground.

First, try to remember that the species does not consist only
of adult males -- but of mothers carrying infants up there,
and attending to other small children. (OK, you may _really_
believe that the species consisted only of adult males -- so
treat this as a kind of exercise, or just a good mental
discipline.)

> "rmacfarl" <rmacfarl@alphalink.com.au> wrote in message new-
> s:1125301280.342279.221630@g44g2000cwa.googlegroups.com...

> > What I've seen of chimps suggest a similar approach. I
> > have a mental image of males hunting by climbing outward
> > on all fours toward a trapped monkey, for example.

Chimps RUN along such branches -- they move really fast when
they are catching monkeys.

> Which was my point, of course. Those 3 or 4 points of
> contact are not necessarily the same branch.

For chimps, chasing monkeys, they often are (indeed, that is
usually the case).

> I know the difficulty. The problem, as I see it, is how you
> get an otherwise four-footed primate to stand up whilst
> engaged in the normal, everyday activities of a quadruped.

All you have to do is to see them placed in an environment
where there are NO suitable trees. Of course, that means no
dangerous predators, forcing them to stay in trees. But there
are plenty of such situations: Present- day Borneo or
Madagascar, for example -- assuming that there were no humans
in such places.

> It *may* be that these adjustments are the result of
> increasing body size --which may be a reaction to something
> else (like scarce resources or sexual politics).

Nope. That dilemma is faced by our cousins -- in every
generation. There are only two real answers -- stay small
enough to sleep in trees (chimps), or let the males get so
huge that they can stay on the ground able to fight off
predators (gorillas).

> Increasing body size then introduces all these other
> difficulties --how to move efficiently in an environment
> with shrinking possibilities. If you're restricted to the
> larger branches, you would be restricted in your adaptive
> responses. Once you have a *climbing* orthograde ape, moving
> it to the ground becomes a natural progression. Figuring out
> what drove this move is another difficulty hinted at
> previously. Were they pushed, pulled, what?

'Pushing' is evolutionary nonsense. So is 'pulling' (in nearly
all scenarios). Just put them in an environment where they do
not face the pressures that keep chimps and female gorillas
sleeping in trees on nearly every night of their lives.

> Did they leave because the trees dropped out from under them
> or were they drawn away by the promise of more lucrative
> jobs in the city? I think that it is pretty well established
> that at some point our ancestors were *living* in trees. We
> now live on the ground.

Avoid the word 'live'. It's too vague. Use 'sleep'. Then you
might be able to focus on the problem.

Paul.

[Jim McGinn]

Rich Travsky wrote:
> mclark wrote:
> >
> > "rmacfarl" <rmacfarl@alphalink.com.au> wrote in message
> > news:1125114048.973601.63410@f14g2000cwb.googlegroups.-
> > com...
> > > Mclark,
> > >
> > > I'm interested in this idea you've previously floated
> > > about the origin of bipedalism being linked to arboreal
> > > origins. I know it's been brought up usually in
> > > opposition to all that wet theorising, but I'd like to
> > > hear you expound on your idea bit further. Care to have
> > > a crack?
> >
> > Well, if you ask me, I think this whole 90% twist from
> > horizontal to vertical is a response to the problem of
> > moving an increasingly large body through the branches of
> > trees. I think I had this conversation with Pauline a
> > while back and if I recall (without a search), I think
> > that I said something about the nature of trees (they have
> > a vertical trunk, in most cases, branches angle off from
> > this trunk at increasing angles as they move away from the
> > trunk and that useful resources are usually found toward
> > the termination of these branches), and that larger bodies
> > would be restricted by certain physical laws from
> > employing the normal monkey modes of travel. As these
> > increasingly large apes were restricted toward the center
> > of the tree, they were increasingly relegated to vertical
> > climbing (the vertical trunk), prevented from brachiating
> > (more central branches are larger). That leaves them with
> > the upper surfaces of larger branches. Foraging, and
> > supplementing their balance with their hands by grasping
> > nearby branches, these apes would find themselves with
> > their feet both *on the ground* and acting as the sole
> > interface with the substrate. Add this to the fact that
> > running along the tops of branches is actually *more*
> > stable that walking, and the observation that *sitting*
> > adds its own set of variables to the mix (changes to the
> > lower spine) and you have a certain inevitability to the
> > notion that those apes thus pre-adapted to bipedalism
> > would find themselves moving bipedally when ~whatever~
> > moved them to the ground. "Whatever" could be anything
> > that would initiate the move from tree to terrestrial --
> > drying and cooling, which would disperse the trees, a mere
> > local preference for a food source on the ground, a
> > population shift in geography, etc.
> >
> > I think R.H Crompton has at least intimated much the same.
> > Check this out:
> > http://www.liv.ac.uk/premog/premog-pubs.htm
>
> Intimates? He flat out sez it:
>
> http://www.trussel.com/prehist/news283.htm ... "Trees were
> an ideal nursery for the learning of human walking,"

Ideal nursery? Thus, bipedalism is, supposedly, a grown-up
form of locomotion. Therefore there is no need to actually
delineate any selective benefits. It's inevitable that
mobility progresses from an infantile stage to an adult stage.

says Robin Compton
> of Liverpool University. "They enable an animal to balance
> itself. They can reach out in any direction, above and
> below themselves, and find branches. Orangutans do just
> this sort of thing."

Idiotic reasoning. As if balancing was the only issue involved
with the origins of bipedalism.

>
> And having got our bipedal act right, we were then
> perfectly placed, when the climate changed 2 million years
> later, and forests thinned, to walk out on the savanna with
> our hands free to make tools and carry food to caves.

Make what tools, when. More vague nonsense. The reasoning here
is hardly any better than AAT.

> ...
>
> That being said, gorillas, chimps, orangs and even monkeys
> exhibit this behavior too; only gorillas and chimps went to
> the ground. Something more is needed.
>
> See also the Bwindi project
>
> http://www-rcf.usc.edu/~stanford/bigape.html The
> Bwindi-Impenetrable Great Ape Project ... A second recent
> finding is that Bwindi chimpanzees are more bipedal in
> posture, at least when feeding in trees,

Yes, and when moving through water.

than other documented chimpanzee
> populations. During May, 2001, while feeding in Ficus sp.,
> the Ruhija chimpanzees foraged in the tree bipedally
> (standing on the largest terminal branches) more often in
> a ten day period than other studies have recorded in a
> year or more. A total of 38.5 hours of observational data
> were collected on 20 individuals, during which 78
> instances of bipedalism by nine individuals were recorded,
> an average of 0.49 bouts per observation hour for the
> entire community. All bipedalism occurred arboreally on
> the larger limbs of the Ficus natalensis, and all
> instances occurred in a fig-fruit feeding context.
> Individuals varied widely in their tendency to be bipedal,
> as well as the average duration of their bipedal bouts.
> One male was bipedal at least 24 times in approximately 20
> contact hours. The sample included four adult males and
> four adult females; males were bipedal significantly more
> often than females. A manuscript about this behavior is
> currently in preparation. ...
>
> and the chimps at Semliki
>
> http://alumni.indiana.edu/magazine/jan-feb01/evolution-ape-
> s.html ... The question is at the heart of Kevin Hunt's
> studies of chimpanzees in the wilds of Uganda. By observing
> the contexts in which these animals are bipedal in their
> natural habitat, the IUB anthropology professor hopes to
> understand why humans became bipedal, walking on two legs
> instead of four. ... Hunt observed that 85 percent of the
> time the chimpanzees were standing on two legs, they were
> gathering fruit from trees. Sometimes they were able to
> reach the fruit from the ground, but most of the time they
> stood in the trees, gripping the branches with their long
> toes and hanging on to the fruit-laden branches above to
> pull the food within their grasp. The behavior was
> particularly pronounced when the chimpanzees were foraging
> in small trees.
>
> "The conclusion I came to is that chimpanzees are unique
> among primates because they feed hanging from one arm,"
> Hunt says. "My theory is that bipedalism evolved when human
> ancestors stood up to gather fruit both from the ground and
> suspended bipedally in trees. If the trees were all small,
> they would do it more."
>
> Hunt began to draw parallels between chimpanzees and
> australopethicines, the most primitive human ancestors.
> Like chimpanzees, australopethicines had extremely long
> toes. They also had, Hunt believes, a similar pelvis and
> the same kind of long shoulder blades and upward-facing
> shoulder joints as chimpanzees, suggesting that they, too,
> may once have hung from trees. What's more,
> australopethicines would have lived in a time when the
> climate was dry and trees were short - one reason for them
> to stand on the ground and reach up to gather fruit. ...
> Hunt's initial observations are promising. The chimpanzees
> at Semliki consistently stand on two legs when feeding, as
> well as when fighting and carrying their young. ...
>
> Arizona State University used to have the link
>
> http://www.asu.edu/clas/iho/hunt_abs.html
>
> which apparently is gone. It had the following bit:
>
> Kevin Hunt, Ph.D., Indiana University Chimpanzee
> Food-Getting Strategies Hint at the Origin of Bipedalism
>
> Although chimpanzees prefer dense, moist forest, most of
> their bipedalism was in dryer habitats. Perhaps something
> about drier ecozones elicits bipedalism.

uh, yes, see my Ecological Gatekeeper Hypothesis.

>
> which ties together the above excerpts.
>
> > > [Watery types need not apply...]
> > >
> > > Ross Macfarlane
>

[Rich Travs]

mclark wrote:
>
> "rmacfarl" <rmacfarl@alphalink.com.au> wrote in message new-
> s:1125114048.973601.63410@f14g2000cwb.googlegroups.com...
> > Mclark,
> >
> > I'm interested in this idea you've previously floated
> > about the origin of bipedalism being linked to arboreal
> > origins. I know it's been brought up usually in opposition
> > to all that wet theorising, but I'd like to hear you
> > expound on your idea bit further. Care to have a crack?
>
> Well, if you ask me, I think this whole 90% twist from
> horizontal to vertical is a response to the problem of
> moving an increasingly large body through the branches of
> trees. I think I had this conversation with Pauline a while
> back and if I recall (without a search), I think that I said
> something about the nature of trees (they have a vertical
> trunk, in most cases, branches angle off from this trunk at
> increasing angles as they move away from the trunk and that
> useful resources are usually found toward the termination of
> these branches), and that larger bodies would be restricted
> by certain physical laws from employing the normal monkey
> modes of travel. As these increasingly large apes were
> restricted toward the center of the tree, they were
> increasingly relegated to vertical climbing (the vertical
> trunk), prevented from brachiating (more central branches
> are larger). That leaves them with the upper surfaces of
> larger branches. Foraging, and supplementing their balance
> with their hands by grasping nearby branches, these apes
> would find themselves with their feet both *on the ground*
> and acting as the sole interface with the substrate. Add
> this to the fact that running along the tops of branches is
> actually *more* stable that walking, and the observation
> that *sitting* adds its own set of variables to the mix
> (changes to the lower spine) and you have a certain
> inevitability to the notion that those apes thus pre-adapted
> to bipedalism would find themselves moving bipedally when
> ~whatever~ moved them to the ground. "Whatever" could be
> anything that would initiate the move from tree to
> terrestrial -- drying and cooling, which would disperse the
> trees, a mere local preference for a food source on the
> ground, a population shift in geography, etc.
>
> I think R.H Crompton has at least intimated much the same.
> Check this out: http://www.liv.ac.uk/premog/premog-pubs.htm

Intimates? He flat out sez it:

http://www.trussel.com/prehist/news283.htm ... "Trees were an
ideal nursery for the learning of human walking," says Robin
Compton of Liverpool University. "They enable an animal to
balance itself. They can reach out in any direction, above
and below themselves, and find branches. Orangutans do just
this sort of thing."

And having got our bipedal act right, we were then perfectly
placed, when the climate changed 2 million years later, and
forests thinned, to walk out on the savanna with our hands
free to make tools and carry food to caves. ...

That being said, gorillas, chimps, orangs and even monkeys
exhibit this behavior too; only gorillas and chimps went to
the ground. Something more is needed.

See also the Bwindi project

http://www-rcf.usc.edu/~stanford/bigape.html The
Bwindi-Impenetrable Great Ape Project ... A second recent
finding is that Bwindi chimpanzees are more bipedal in
posture, at least when feeding in trees, than other
documented chimpanzee populations. During May, 2001, while
feeding in Ficus sp., the Ruhija chimpanzees foraged in the
tree bipedally (standing on the largest terminal branches)
more often in a ten day period than other studies have
recorded in a year or more. A total of 38.5 hours of
observational data were collected on 20 individuals, during
which 78 instances of bipedalism by nine individuals were
recorded, an average of 0.49 bouts per observation hour for
the entire community. All bipedalism occurred arboreally on
the larger limbs of the Ficus natalensis, and all instances
occurred in a fig-fruit feeding context. Individuals varied
widely in their tendency to be bipedal, as well as the
average duration of their bipedal bouts. One male was
bipedal at least 24 times in approximately 20 contact
hours. The sample included four adult males and four adult
females; males were bipedal significantly more often than
females. A manuscript about this behavior is currently in
preparation. ...

and the chimps at Semliki

http://alumni.indiana.edu/magazine/jan-feb01/evolution-apes.-
html ... The question is at the heart of Kevin Hunt's studies
of chimpanzees in the wilds of Uganda. By observing the
contexts in which these animals are bipedal in their natural
habitat, the IUB anthropology professor hopes to understand
why humans became bipedal, walking on two legs instead of
four. ... Hunt observed that 85 percent of the time the
chimpanzees were standing on two legs, they were gathering
fruit from trees. Sometimes they were able to reach the fruit
from the ground, but most of the time they stood in the
trees, gripping the branches with their long toes and hanging
on to the fruit-laden branches above to pull the food within
their grasp. The behavior was particularly pronounced when
the chimpanzees were foraging in small trees.

"The conclusion I came to is that chimpanzees are unique
among primates because they feed hanging from one arm," Hunt
says. "My theory is that bipedalism evolved when human
ancestors stood up to gather fruit both from the ground and
suspended bipedally in trees. If the trees were all small,
they would do it more."

Hunt began to draw parallels between chimpanzees and
australopethicines, the most primitive human ancestors. Like
chimpanzees, australopethicines had extremely long toes.
They also had, Hunt believes, a similar pelvis and the same
kind of long shoulder blades and upward-facing shoulder
joints as chimpanzees, suggesting that they, too, may once
have hung from trees. What's more, australopethicines would
have lived in a time when the climate was dry and trees were
short — one reason for them to stand on the ground and reach
up to gather fruit. ... Hunt's initial observations are
promising. The chimpanzees at Semliki consistently stand on
two legs when feeding, as well as when fighting and carrying
their young. ...

Arizona State University used to have the link

http://www.asu.edu/clas/iho/hunt_abs.html

which apparently is gone. It had the following bit:

Kevin Hunt, Ph.D., Indiana University Chimpanzee Food-Getting
Strategies Hint at the Origin of Bipedalism

Although chimpanzees prefer dense, moist forest, most of
their bipedalism was in dryer habitats. Perhaps something
about drier ecozones elicits bipedalism.

which ties together the above excerpts.

> > [Watery types need not apply...]
> >
> > Ross Macfarlane

[McLark]

"Rich Travsky" <" traRvEsky"@hotmMOVEail.com> wrote in message
news:431BB840.C8530B5@hotmMOVEail.com...
> mclark wrote:

[...]

>> I think R.H Crompton has at least intimated much the same.
>> Check this out: http://www.liv.ac.uk/premog/premog-pubs.htm
>
> Intimates? He flat out sez it:
>
> http://www.trussel.com/prehist/news283.htm

Too bad there aint some emoticon for tongue-in-cheek.
Maybe :-§ ?

...
> "Trees were an ideal nursery for the learning of human
> walking," says Robin Compton of Liverpool University. "They
> enable an animal to balance itself. They can reach out in
> any direction, above and below themselves, and find
> branches. Orangutans do just this sort of thing."

[..]
--
"You might be right but, people shouldn't buy it unless you
can *demonstrate* it through logical reasoning and/or
evidence and I just don't think you have done that." ---Algis
Kuliukas 08/14/05

[Marc Verha]

> http://www.trussel.com/prehist/news283.htm ... "Trees were
> an ideal
nursery for the learning of human walking," says Robin Compton

Yes, my boy, that's why all primates are bipedal...

:-D

[Alas My Lo]

Rich,

Per above, apiths & chimps have long toes.

AFAIK humans have short toes.

Gibbons & humans are obligate bipedalists in compressional
locomotion.

You mention elsewhere that apiths (all spp. IYO?) were
obligate bipedalists.

Why? Were their arms so short that they could not habitually
palmwalk or knuckle-walk or fist-walk? DD

[Rmacfarl]

alas_my_loves@yahoo.com wrote:
> Rich,
>
> Per above, apiths & chimps have long toes.
>
> AFAIK humans have short toes.
>
> Gibbons & humans are obligate bipedalists in compressional
> locomotion.
>
> You mention elsewhere that apiths (all spp. IYO?) were
> obligate bipedalists.
>
> Why? Were their arms so short that they could not habitually
> palmwalk or knuckle-walk or fist-walk? DD

Arms were shorter relative to legs than chimps, but more
importantly, the skull (foramen magnum), pelvis (bowl-shaped)
& knee (valgus angle) of an australopith are heavily modified
/ derived in the direction of obligate bipedalism...

Ross Macfarlane

[Quercophil]

Jim McGinn wrote:

> 3) Myth: The freeing of the hands that bipedalism enabled in
> our earliest chimpanzee-like ancestors might have enabled
> the use of weapons or tools to achieve hunting or
> scavenging.
>
> Fact: These earliest hominids were millions of years away
> from having the intellect, cooperative behaviors, and
> manipulative abilities necessary to for such a diminutive
> creature to have competed with the large agressive social
> hunters and scavengers that are evident in the fossil record
> of east Africa beginning in the middle miocene, about 8 mya.
> (Moreover, only in the context of a scenario that involves
> communalism could we ever expect them to evolve such
> intellectual and cooperative abilities.)

I generally agree with all your other assertions but find this
one questionable. Why is social cooperation or acute
intellectual abilities necessary for tool use, such as picking
up and rock and chucking it or swinging a stick? People have
seen chimpanzees throwing objects at intruders and tool use in
other contexts has also been seen. Moving to bipedality is an
enormous challenge. The only payoff I can see for paying the
inevitable costs is greater utility for the upper limbs.

[Alas My Lo]

rmacfarl wrote:
> alas_my_loves@yahoo.com wrote:
> > Rich,
> >
> > Per above, apiths & chimps have long toes.
> >
> > AFAIK humans have short toes.
> >
> > Gibbons & humans are obligate bipedalists in compressional
> > locomotion.
> >
> > You mention elsewhere that apiths (all spp. IYO?) were
> > obligate bipedalists.
> >
> > Why? Were their arms so short that they could not
> > habitually palmwalk or knuckle-walk or fist-walk? DD
>
> Arms were shorter relative to legs than chimps, but more
> importantly, the skull (foramen magnum), pelvis
> (bowl-shaped) & knee (valgus angle) of an australopith are
> heavily modified / derived in the direction of obligate
> bipedalism...
>
> Ross Macfarlane

How long were hands (knuckle, palm, fist) to trunk as opposed
to sole to trunk...would seem relevant. DD

[Rmacfarl]

<alas_my_loves@yahoo.com> wrote in message
news:1126305036.271003.148760@g43g2000cwa.googlegroups.com...
>
> rmacfarl wrote:
>> alas_my_loves@yahoo.com wrote:
>> > Rich,
>> >
>> > Per above, apiths & chimps have long toes.
>> >
>> > AFAIK humans have short toes.
>> >
>> > Gibbons & humans are obligate bipedalists in
>> > compressional locomotion.
>> >
>> > You mention elsewhere that apiths (all spp. IYO?) were
>> > obligate bipedalists.
>> >
>> > Why? Were their arms so short that they could not
>> > habitually palmwalk or knuckle-walk or fist-walk? DD
>>
>> Arms were shorter relative to legs than chimps, but more
>> importantly, the skull (foramen magnum), pelvis
>> (bowl-shaped) & knee (valgus angle) of an australopith are
>> heavily modified / derived in the direction of obligate
>> bipedalism...
>>
>> Ross Macfarlane
>
> How long were hands (knuckle, palm, fist) to trunk as
> opposed to sole to trunk...would seem relevant. DD

Would it? How?

What's relevant is that australopiths' backs, hips & knees
were evolved for erect posture. Unless you are a supporter of
the Port Adelaide Football Club, if you stand upright, you
will find that your knuckles don't reach the ground...

Ross Macfarlane

[Alas My Lo]

Gibbons are obligate bipedalists in compressional locomotion
(personal observation, Wildlife Fact File). Gibbons' arms are
typically 1/3 longer than their trunk.

Humans are obligate bipedalists in compressional locomotion,
with legs significantly longer than arms.

Apiths had legs longer than arms. How much longer? Slightly or
significantly?

Dave

[Alas My Lo]

I've no doubts about apiths being occasional bipeds or even
habitual bipeds in compressional locomotion, but the word
"obligate" should only be used if proven. Very long arms w/
short legs or very long legs w/ short arms would strongly
indicate obligate bipedalism IMO.

My opinion is that apiths were locomotive generalists,
alternating compressional bipedalism and quadripedalism
(kwalk/fistwalk/palmwalk) and tensional bimanualism and/or
quadrimanualism as the feeding opportunity or environmental
condition arose. DD

[Marc Verha]

<alas_my_loves@yahoo.com> wrote in message
news:1126305036.271003.148760@g43g2000cwa.googlegroups.com...

> > > You mention elsewhere that apiths (all spp. IYO?) were
> > > obligate
bipedalists.

A lot of PAs keep repeating this without good evidence. What
we do know is that apiths (esp.graciles) had curved phalanges
(branch-hanging) and (esp.E.Afr.spp) had knuckle-walking
features. Bipedal gait is proved by the Laetoli footprints,
but this is also often seen in chimps, eg, RJ Clarke 1999
"Discovery of complete arm & hand of the 3.3-Ma Australop
skeleton from Stf " SAJS 95:477-480 "... In 1985, my thoughts
concerning the arboreal nature of the Laetoli footprints led
me to arrange with the Boswell Wilkie Circus for a male chimp
& a female bonobo to walk bipedally over wet sand. The results
were remarkable ... the timid female walked nervously, digging
her toes in & with wide-spread big toe, the male was confident
and tended to walk with his big toe most often close to the
other toes (Figs 5, 6). The prints that he produced have a
strong resemblance to the Laetoli footprints ..."

> > > Why? Were their arms so short that they could not
> > > habitually palmwalk
or knuckle-walk or fist-walk? DD

> > Arms were shorter relative to legs than chimps, but more
> > importantly,
the skull (foramen magnum), pelvis (bowl-shaped) & knee
(valgus angle) of an australopith are heavily modified /
derived in the direction of obligate bipedalism...

That's nonsense:
- For.magnum position in apiths overlaps with that in bonobos.
- The apith pelvis had the iliac bones +- oriented as in ape
pelvises. Ape pelvises are derived in having much higher
ilia than monkeys, apiths & Homo (see, eg, the well-know
illustrations of Schultz). IOW, the apith pelvis is simply
primitive hominid.
- A valgus knee is NO adaptation to bipedal cursorialism, to
the contrary. It's an adaptation to a rel.slow gait (note Hs
has less valgus knees than He & apiths), with good lateral
abduction of the femora: the laterally flaring ilia & the
long femoral necks were adaptations for femoral abduction,
and when the leg joints have to be on 1 line (hip, knee,
ankle), a valgus knee is necessary (humans have less valgus
knees & shorter & less horizontal femoral necks than erectus
& apiths).
- "Derived in the direction of obligate bipedalism" is
ridiculous. Kangaroos & birds & humans & penguins & jumping
mice & indris are obligate bipeds on the ground. The man
probably means that some features of the apith lower limb
were more human- than chimp-like. What had he thought?
Apiths lived 2-4 My earlier than living hominids (chimps,
humans, gorillas), so why shouldn't they have had features
of chimps & humans?

> How long were hands (knuckle, palm, fist) to trunk as
> opposed to sole to
trunk...would seem relevant. DD

Difficult to know, but it's very likely that early apiths had
rel."short" arms (+- as in humans), so this alone would make
KWing difficult. It's another argument for KWing & long arms
being derived in chimps & gorillas. Early hominids had
rel.short arms & legs. Humans got longer legs. Chimps &
gorillas (in parallel) got longer arms.

--Marc

[Rmacfarl]

alas_my_loves@yahoo.com wrote:
> Gibbons are obligate bipedalists in compressional locomotion
> (personal observation, Wildlife Fact File). Gibbons' arms
> are typically 1/3 longer than their trunk.

That is as a result of a different extreme. Gibbons' arms are
so long that they reach the ground even when they are fully
upright. Essentially they can't walk bipedally.

>
> Humans are obligate bipedalists in compressional locomotion,
> with legs significantly longer than arms.
>
> Apiths had legs longer than arms. How much longer? Slightly
> or significantly?

Slightly. From memory, upper arm about 90-95% of the length of
the upper leg bone. In humans it's 80-85%, chimps I think
about 105%.

But again, point is not arm length, it is the fact that
australopiths are evolved for upright posture. They show a
number of highly derived skeletal features that parallel
humans, not great apes. e.g.:

- Foramen magnum located under skull = skull positioned on top
of spine, not at rear of skull as in quadrupedal apes;

- Bowl-shaped pelvis, adapted for upright posture;

- Valgus knee angle, ditto.

Check out comparison of Lucy's pelvis & knee vs. human & chimp
in this link: how could anyone look at this & not recognise
the ancestral relationship between humans & australopiths? -
http://www.anthro4n6.net/lucy/

And someone tell Marc to piss off out of this thread...

Ross Macfarlane

[Marc Verha]

<alas_my_loves@yahoo.com> wrote in message
news:1126383711.679869.120900@o13g2000cwo.googlegroups.com...

> I've no doubts about apiths being occasional bipeds or even
> habitual
bipeds in compressional locomotion, but the word "obligate"
should only be used if proven. Very long arms w/ short legs or
very long legs w/ short arms would strongly indicate obligate
bipedalism IMO.

As in gibbons, resp. humans, you mean? Interesting thinking.
Apiths had rel.short arms & legs.

> My opinion is that apiths were locomotive generalists,
> alternating
compressional bipedalism and quadrupedalism
(kwalk/fistwalk/palmwalk) and tensional bimanualism and/or
quadrumanualism as the feeding opportunity or environmental
condition arose. DD

Yes, most gracile apiths lived in swale/gallery forests etc. I
guess they climbed arms overhead, often waded & also walked on
2 legs & perhaps regularly KWed. The robusts lived in more
open habitats & seem to have climbed less. KWing features have
been described esp. in the E.Afr.apiths (anamensis, Lucy,
boisei), but AFAIK, not in the S.Afr.apiths.

--Marc

[Marc Verha]

<alas_my_loves@yahoo.com> wrote in message
news:1126381822.850626.32630@f14g2000cwb.googlegroups.com...

> Gibbons are obligate bipedalists in compressional locomotion
> (personal
observation, Wildlife Fact File). Gibbons' arms are typically
1/3 longer than their trunk. Humans are obligate bipedalists
in compressional locomotion, with legs significantly longer
than arms. Apiths had legs longer than arms. How much longer?
Slightly or significantly? Dave

Difficult to know exactly (incomplete skeletons & broken
bones). Lucy had arms probably shorter than pygmy humans
(humerus ~23? vs 25 cm), & legs a lot shorter (femur ~28 vs
33.5 cm). Hum.:femur ~0.75 in human pygmies, ?~82 in Lucy.
Female bonobos humerus ~ femur ~ 29 cm. Humans humerus ~ 33
cm, femur ~ 45 cm (hum.:femur ~0.73).

--Marc

[Rich Travs]

alas_my_loves@yahoo.com wrote:
>
> Rich,
>
> Per above, apiths & chimps have long toes.
>
> AFAIK humans have short toes.
>
> Gibbons & humans are obligate bipedalists in compressional
> locomotion.
>
> You mention elsewhere that apiths (all spp. IYO?) were
> obligate bipedalists.
>
> Why? Were their arms so short that they could not habitually
> palmwalk or knuckle-walk or fist-walk?

Using Lucy as a reference, several features of the skeletal
remains show obligate bipedalism.

http://www.asu.edu/clas/iho/lucy.html ... How do we know Lucy
walked upright?

As in a modern human's skeleton, Lucy's bones are rife with
evidence clearly pointing to bipedality. Her distal femur
shows several traits unique to bipedality. The shaft is angled
relative to the condyles (knee joint surfaces) which allows
bipeds to balance on one leg at a time during locomotion.
There is a prominent patellar lip to keep the patella (knee
cap) from dislocating due to this angle. Her condyles are
large, and are thus adapted to handling the added weight which
results from shifting from four limbs to two. The pelvis
exhibits a number of adaptations to bipedality. The entire
structure has been remodeled to accommodate an upright stance
and the need to balance the trunk on only one limb with each
stride. The talus, in her ankle, shows evidence for a
convergent big toe, sacrificing manipulative abilities for
efficiency in bipedal locomotion. The vertebrae show evidence
of the spinal curvatures necessitated by a permanent upright
stance. ...

The above does not mention that the foramen magnum is situated
like that in humans, underneath the skull, further confirming
a bipedal orientation.

Here's Lucy's knee

http://www.liverpool.ac.uk/premog/images/lucy_knee.jpg

where the order is human, Lucy, chimp in the picture.

(the above from the link

http://www.liverpool.ac.uk/premog/premog-research.htm )

And here

http://www.anthro4n6.net/lucy/

scroll down to the image showing the pelvis and femur
arrangements of a chimp, an australopith, and a human.

There is one and only one conclusion: obligate bipedalism.

[Rich Travs]

rmacfarl wrote:
>
> alas_my_loves@yahoo.com wrote:
> > Gibbons are obligate bipedalists in compressional
> > locomotion (personal observation, Wildlife Fact File).
> > Gibbons' arms are typically 1/3 longer than their trunk.
>
> That is as a result of a different extreme. Gibbons' arms
> are so long that they reach the ground even when they are
> fully upright. Essentially they can't walk bipedally.

Not exactly so.

http://home13.inet.tele.dk/palm/homcom-filer/gibbon.gif

I had a better one but the site is gone.

> > Humans are obligate bipedalists in compressional
> > locomotion, with legs significantly longer than arms.
> >
> > Apiths had legs longer than arms. How much longer?
> > Slightly or significantly?
>
> Slightly. From memory, upper arm about 90-95% of the length
> of the upper leg bone. In humans it's 80-85%, chimps I think
> about 105%.
>
> But again, point is not arm length, it is the fact that
> australopiths are evolved for upright posture. They show a
> number of highly derived skeletal features that parallel
> humans, not great apes. e.g.:
>
> - Foramen magnum located under skull = skull positioned on
> top of spine, not at rear of skull as in quadrupedal apes;
>
> - Bowl-shaped pelvis, adapted for upright posture;
>
> - Valgus knee angle, ditto.
>
> Check out comparison of Lucy's pelvis & knee vs. human &
> chimp in this link: how could anyone look at this & not
> recognise the ancestral relationship between humans &
> australopiths? - http://www.anthro4n6.net/lucy/
>
> And someone tell Marc to piss off out of this thread...
>
> Ross Macfarlane

[Marc Verha]

"Rich Travsky" <" traRvEsky"@hotmMOVEail.com> wrote in message
news:4323D05A.4DA569F6@hotmMOVEail.com...

> How do we know Lucy walked upright? As in a modern human's
> skeleton,
Lucy's bones are rife with evidence clearly pointing to
bipedality. Her distal femur shows several traits unique to
bipedality. The shaft is angled relative to the condyles (knee
joint surfaces) which allows bipeds to balance on one leg at a
time during locomotion.

This is ridiculous nonsense.

In humans, the hip + knee + ankle *joints* are on 1 line. This
is for stability, esp. when standing. Humans have femoral
necks, see anatomy book. If the joints have to be on 1 line,
there has to be a valgus knee ("shaft angles rel.to
condyles"). If the femoral necks are rel.longer (as in
H.erectus & Lucy), this valgus has to be greater. It has
*nothing* to do with balancing.

IOW, long fem.neck = very valgus.

More interesting question:
Q: Why did Lucy & H.erectus, more than H.sapiens, have long
femoral necks (& hence needed valgus knees)?
R: For femoral abduction.

First consider this carefully, Travsky, before writing
further nonsense.

[Rich Travs]

Marc Verhaegen wrote:
>
> <alas_my_loves@yahoo.com> wrote in message news:1126305036.-
> 271003.148760@g43g2000cwa.googlegroups.com...
>
> > > > You mention elsewhere that apiths (all spp. IYO?) were
> > > > obligate
> bipedalists.
>
> A lot of PAs keep repeating this without good evidence. What
> we do know is

WHAT????? The skeleton is conclusive.

http://www.liverpool.ac.uk/premog/premog-research.htm

http://www.anthro4n6.net/lucy/

> that apiths (esp.graciles) had curved phalanges
> (branch-hanging) and (esp.E.Afr.spp) had knuckle-walking
> features. Bipedal gait is proved by the Laetoli footprints,
> but this is also often seen in chimps, eg, RJ Clarke 1999
> "Discovery of complete arm & hand of the 3.3-Ma Australop
> skeleton from Stf " SAJS 95:477-480 "... In 1985, my
> thoughts concerning the arboreal nature of the Laetoli
> footprints led me to arrange with the Boswell Wilkie Circus
> for a male chimp & a female bonobo to walk bipedally over
> wet sand. The results were remarkable ... the timid female
> walked nervously, digging her toes in & with wide-spread big
> toe, the male was confident and tended to walk with his big
> toe most often close to the other toes (Figs 5, 6). The
> prints that he produced have a strong resemblance to the
> Laetoli footprints ..."
>
> > > > Why? Were their arms so short that they could not
> > > > habitually palmwalk
> or knuckle-walk or fist-walk? DD
>
> > > Arms were shorter relative to legs than chimps, but more
> > > importantly,
> the skull (foramen magnum), pelvis (bowl-shaped) & knee
> (valgus angle) of an australopith are heavily modified /
> derived in the direction of obligate bipedalism...
>
> That's nonsense:
> - For.magnum position in apiths overlaps with that in
> bonobos.
> - The apith pelvis had the iliac bones +- oriented as in ape
> pelvises. Ape pelvises are derived in having much higher
> ilia than monkeys, apiths & Homo (see, eg, the well-know
> illustrations of Schultz). IOW, the apith pelvis is simply
> primitive hominid.
> - A valgus knee is NO adaptation to bipedal cursorialism, to
> the contrary. It's an adaptation to a rel.slow gait (note
> Hs has less valgus knees than He & apiths), with good
> lateral abduction of the femora: the laterally flaring
> ilia & the long femoral necks were adaptations for femoral
> abduction, and when the leg joints have to be on 1 line
> (hip, knee, ankle), a valgus knee is necessary (humans
> have less valgus knees & shorter & less horizontal femoral
> necks than erectus & apiths).
> - "Derived in the direction of obligate bipedalism" is
> ridiculous. Kangaroos & birds & humans & penguins &
> jumping mice & indris are obligate bipeds on the ground.
> The man probably means that some features of the apith
> lower limb were more human- than chimp-like. What had he
> thought? Apiths lived 2-4 My earlier than living hominids
> (chimps, humans, gorillas), so why shouldn't they have had
> features of chimps & humans?
>
> > How long were hands (knuckle, palm, fist) to trunk as
> > opposed to sole to
> trunk...would seem relevant. DD
>
> Difficult to know, but it's very likely that early apiths
> had rel."short" arms (+- as in humans), so this alone would
> make KWing difficult. It's another argument for KWing & long
> arms being derived in chimps & gorillas. Early hominids had
> rel.short arms & legs. Humans got longer legs. Chimps &
> gorillas (in parallel) got longer arms.
>
> --Marc

[Marc Verha]

"Rich Travsky" <" traRvEsky"@hotmMOVEail.com> wrote in message
news:4323D25B.C3A949CD@hotmMOVEail.com...

> > > > > You mention elsewhere that apiths (all spp. IYO?)
> > > > > were obligate
bipedalists. DD

> > A lot of PAs keep repeating this without good evidence.
> > What we do know
is

> WHAT????? The skeleton is conclusive.
http://www.liverpool.ac.uk/premog/premog-research.htm
http://www.anthro4n6.net/lucy/

Sigh. As usual, you're not following. Once again. Try to
follow, my boy. No difficult. Only requires a very little
bit of logic.

Why do PAs say apiths were bipedal? Because their hindlimbs
bear resemblances not only to apes but also to humans.
Short-sighted people like you reason like this: evolution
was from apelike to apith to human, humans are obligatory
bipeds, hence appearance of human-like features in apiths
suggests they walked a lot. But the evolution was not
ape>apith>H. It was HP-LCA>H & HP-LCA>P. Still following?
Obviously most apiths were more like HP-LCA than like living
H or like living P.

IOW, that apith fossils show humanlike features (& apelike
features & unique features) is to be expected: they lived 2-4
Ma, as you might know. This this does not mean they ran on 2
legs, only that they wer more primitive than living P or H.
Humans are derived in 1 direction, P in another, but both had
the same HP-LCA ~5 Ma.

Okidoki?

Now read further instead of interrupting with irrelevancies:

> > that apiths (esp.graciles) had curved phalanges
> > (branch-hanging) and (esp.E.Afr.spp) had knuckle-walking
> > features. Bipedal gait is proved by
the
> > Laetoli footprints, but this is also often seen in chimps,
> > eg, RJ Clarke 1999 "Discovery of complete arm & hand of
> > the 3.3-Ma Australop skeleton
from
> > Stf " SAJS 95:477-480 "... In 1985, my thoughts concerning
> > the arboreal nature of the Laetoli footprints led me to
> > arrange with the Boswell
Wilkie
> > Circus for a male chimp & a female bonobo to walk
> > bipedally over wet
sand.
> > The results were remarkable ... the timid female walked
> > nervously,
digging
> > her toes in & with wide-spread big toe, the male was
> > confident and
tended to
> > walk with his big toe most often close to the other toes
> > (Figs 5, 6).
The
> > prints that he produced have a strong resemblance to the
> > Laetoli
footprints
> > ..."
> >
> > > > > Why? Were their arms so short that they could not
> > > > > habitually
palmwalk
> > or knuckle-walk or fist-walk? DD
> >
> > > > Arms were shorter relative to legs than chimps, but
> > > > more
importantly,
> > the skull (foramen magnum), pelvis (bowl-shaped) & knee
> > (valgus angle)
of an
> > australopith are heavily modified / derived in the
> > direction of obligate bipedalism...
> >
> > That's nonsense:
> > - For.magnum position in apiths overlaps with that in
> > bonobos.
> > - The apith pelvis had the iliac bones +- oriented as in
> > ape pelvises.
Ape
> > pelvises are derived in having much higher ilia than
> > monkeys, apiths &
Homo
> > (see, eg, the well-know illustrations of Schultz). IOW,
> > the apith
pelvis is
> > simply primitive hominid.
> > - A valgus knee is NO adaptation to bipedal cursorialism,
> > to the
contrary.
> > It's an adaptation to a rel.slow gait (note Hs has less
> > valgus knees
than He
> > & apiths), with good lateral abduction of the femora: the
> > laterally
flaring
> > ilia & the long femoral necks were adaptations for femoral
> > abduction,
and
> > when the leg joints have to be on 1 line (hip, knee,
> > ankle), a valgus
knee
> > is necessary (humans have less valgus knees & shorter &
> > less horizontal femoral necks than erectus & apiths).
> > - "Derived in the direction of obligate bipedalism" is
> > ridiculous. Kangaroos & birds & humans & penguins &
> > jumping mice & indris are
obligate
> > bipeds on the ground. The man probably means that some
> > features of the apith lower limb were more human- than
> > chimp-like. What had he thought? Apiths lived 2-4 My
> > earlier than living hominids (chimps, humans,
gorillas),
> > so why shouldn't they have had features of chimps &
> > humans?
> >
> > > How long were hands (knuckle, palm, fist) to trunk as
> > > opposed to sole
to
> > trunk...would seem relevant. DD
> >
> > Difficult to know, but it's very likely that early
> > apiths had
rel."short"
> > arms (+- as in humans), so this alone would make KWing
> > difficult. It's another argument for KWing & long arms
> > being derived in chimps &
gorillas.
> > Early hominids had rel.short arms & legs. Humans got
> > longer legs.
Chimps &
> > gorillas (in parallel) got longer arms.
> >
> > --Marc

[McLark]

<alas_my_loves@yahoo.com> wrote in message
news:1126383711.679869.120900@o13g2000cwo.googlegroups.com...
> I've no doubts about apiths being occasional bipeds or even
> habitual bipeds in compressional locomotion, but the word
> "obligate" should only be used if proven. Very long arms w/
> short legs or very long legs w/ short arms would strongly
> indicate obligate bipedalism IMO.

"Very long arms w/ short legs or very long legs w/ short arms
would strongly indicate obligate bipedalism IMO."
--"Alas_my_loves", 09/10/05

Whadya figure, a wet ape, or simply someone lost along the
way?

> My opinion is that apiths were locomotive generalists,
> alternating compressional bipedalism and quadripedalism
> (kwalk/fistwalk/palmwalk) and tensional bimanualism and/or
> quadrimanualism as the feeding opportunity or environmental
> condition arose. DD
--
"You might be right but, people shouldn't buy it unless you
can *demonstrate* it through logical reasoning and/or
evidence and I just don't think you have done that." ---Algis
Kuliukas 08/14/05

[Jim McGinn]

quercophile wrote:
> Jim McGinn wrote:
>
> > 3) Myth: The freeing of the hands that bipedalism enabled
> > in our earliest chimpanzee-like ancestors might have
> > enabled the use of weapons or tools to achieve hunting
> > or scavenging.
> >
> > Fact: These earliest hominids were millions of years away
> > from having the intellect, cooperative behaviors, and
> > manipulative abilities necessary to for such a diminutive
> > creature to have competed with the large agressive social
> > hunters and scavengers that are evident in the fossil
> > record of east Africa beginning in the middle miocene,
> > about 8 mya. (Moreover, only in the context of a scenario
> > that involves communalism could we ever expect them to
> > evolve such intellectual and cooperative abilities.)
>
> I generally agree with all your other assertions but find
> this one questionable. Why is social cooperation or acute
> intellectual abilities necessary for tool use, such as
> picking up and rock and chucking it or swinging a stick?
> People have seen chimpanzees throwing objects at intruders
> and tool use in other contexts has also been seen.

I think I may have mistated something. I agree with you that
social cooperation and/or intellectual abilities at levels of
proficiency higher than those of a chimpanzee are not
necessary for activities involving rock-throwing and/or stick
swinging. As you point out, people have seen chimpanzees
throwing objects at intruders, and even rudimentary tool use
(smashing nuts with stones, fishing termite grubs with sticks,
etc.) is evident. And my own hypothesis indicates this
behavior as the preadaptive behavior that brought about the
evolution of bipedalism in the earliest hominids.

The supposition that I was debating in the passage above was,
therefore, not that rudimentary rock-throwing and
stick-wielding underlies the emergence of bipedalism but that
the emergence of bipedalism involved hunting/scavenging. My
hypothesis explicates how I think rock-throwing, stick-
wielding behavior would have been selectively advantageous in
the earliest years of hominid evolution. And--as I've made
perfectly clear many times over--it has nothing even remotely
to do with hunting, scavenging, or even directly evading
predators. It has to do with a community as a whole achieving
preservation of communal resources--food--by way of
preventing inmigrating species from inmigrating and depleting
these resources (mostly fruit trees). Thereby the community
as a whole may better insure that it has access to resources
through the dry season and thereby avoid starvation, thirst,
and the predatory implications associated with the same.

> Moving to bipedality is an enormous challenge. The only
> payoff I can see for paying the inevitable costs is greater
> utility for the upper limbs.

And I agree with you on this point. Bipedalism, which emerges
very early in the hominid fossil record, could only have
evolved if, to use your words, "greater utility of the upper
limbs," provided some kind of very significant survival
advantage. (The reasons for why I dismiss mobility have been
discussed explicitly in other posts.) What are these survival
advantages? Conventional theorists jumped to the conclusion
that this indicated that early man was a tool-using hunter
scavenger. They also concluded, incorrectly IMO, that hominid
communalism emerged only recently (most say no sooner than
12,000 kya). According to my hypothesis the emergence of
bipedalism and the emergence of communal territorialism go
hand in hand beginning 8.1 mya.

The biggest question, by far, about hominid origins involves
the selective origins of hominid consciousness/intelligence.
My scenario provides the context by which this explanation can
be achieved.

There is nothing about my hypothesis that is inconsistent with
a scientifically accurate understanding of evolution. With
respect to its acceptance the biggest problem my hypothesis
has involves the fact that few scientists possess a
scientifically accurate understanding of evolution. Instead
they possess what can best be described as a dogmatism riddled
caricature of evolution based loosely on Darwin's thinking.
Maybe one of the biggest misconceptions associated with this
caricature-- especially as it effects the acceptance of my
hypothesis-- involves prejudices against group selection. To
put it in a nutshell, there are a lot of people out there that
believe that group selection has been disproven and therefore
my scenario can be dismissed because of it's communal
selective aspects alone. In reality no such disproof has ever
been achieved and group selective scenarios are at least as
viable as selection at any other level of biological
phenomena.

Jim

[Alas My Lo]

I see that MCLARK "Good Humour Man" has shown up. Rather than
wet or dry ape, I prefer "snow man".

I'm from the prairies of Minnesota, "Land of 10,000 lakes",
and 10 big blizzards, and the sea is far away.

The sentence you copied was in context of the paragraph,
before you fragged it.

The following is a copy of my first post to the AAT Group back
in February.

"MV: Does anybody know who is A. Lemak A.S.? He sent me this.

Smithsonian mag. oct. 2001 article on Cheney & Seyfarth
observing baboon troop wading quadripedally through
ponds...photo...."Sylvia" (baboon mother) once made a long
water crossing with her infant clinging to her belly. Since
Sivlia herself could breathe, it did not dawn on her that her
submerged baby couldn't, and as a result, it drowned at her
breast.....Bipedal chimp mother wouldn't have that problem.

Also..Readers Digest Amazing facts book...a Dr. Britton had
put a single chimp "Bongo" on a small island. It snowed, Bongo
would only walk bipedally on the soft snow...like marsh.."

Freeze-dried ape.... voila..... dry ape. okeydokey? DD

[Alas My Lo]

> I've no doubts about apiths being occasional bipeds or even
> habitual bipeds in compressional locomotion, but the word
> "obligate" should only be used if proven. Very long arms w/
> short legs or very long legs w/ short arms would strongly
> indicate obligate bipedalism IMO.

As in gibbons, resp. humans, you mean?

Yes specifically, but true in other apes, apiths and
Homo as well.

Interesting thinking. Apiths had rel.short arms & legs.

Yes. Possibly habitual bipedalists but not obligatory
bipedalists AFAICT. DD

> My opinion is that apiths were locomotive generalists,
> alternating compressional bipedalism and quadrupedalism
> (kwalk/fistwalk/palmwalk) and
tensional bimanualism and/or quadrumanualism as the feeding
opportunity or environmental condition arose. DD

Yes, most gracile apiths lived in swale/gallery forests etc. I
guess they climbed arms overhead, often waded & also walked on
2 legs & perhaps regularly KWed. The robusts lived in more
open habitats & seem to have climbed less. KWing features have
been described esp. in the
E.Afr.apiths (anamensis, Lucy, boisei), but AFAIK, not in the
S.Afr.apiths. --Marc

[Alas My Lo]

Ross: "Essentially they (gibbons) can't walk bipedally".

I watched them walk bipedally, with hands raised in front of
their trunk, at the local zoo. Though most of their time was
spent sitting on a branch or brachiating, occasionally they
would descend to walk 3 - 20 steps bipedally. I saw no
quadripedal compressional locomotion. The only tripedal
posture occurred when pivoting from seated to walking or vice
versa, as humans do.

The adjacent spider monkeys (whose arms and legs are nearly
the same length and prehensile tail is much longer) always
walked quadripedally palmigrady in compressional locomotion,
except when carrying food items (egg, apple) when they all
switched to bipedal compressional locomotion. Dave

[Marc Verha]

"Rich Travsky" <" traRvEsky"@hotmMOVEail.com> wrote in message
news:4323D2D3.F0936923@hotmMOVEail.com...

> > But again, point is not arm length, it is the fact that
> > australopiths
are evolved for upright posture. They show a number of highly
derived skeletal features that parallel humans, not great
apes. e.g.: Foramen magnum located under skull = skull
positioned on top of spine, not at rear of skull as in
quadrupedal apes; - Bowl-shaped pelvis, adapted for upright
posture; - Valgus knee angle, ditto.

The man who wrote this doesn't know much on apes or apiths.
- Foramen magnum positions of gracile apiths & bonobos
overlap.
- Apiths had their iliac blades oriented as in great apes.
Apiths had primitive pelvises. Apes got longer iliac blades,
humans got more bowl-shaped pelvises.
- Apiths had *more* valgus than humans. People who believe
that apelike creatures evolved into apiths who evolved
into humans have to explain why we have less valgus knees
than apiths.

[Alas My Lo]

Lucy's arms are longer than the overall length of her legs,
though not as much as current apes.

So, Lucy definitely shows neither gibbon-like or human-like
obligate bipedalism. Her limb lengths remind me of spider
monkey limbs.

Ross: How could anyone look at this & not recognise the
ancestral relationship between humans & australopiths? -
http://www.anthro4n6.net/lucy/

I don't disagree. But there may have been many very similar
relatives, and I'm not sure that Lucy and other apiths weren't
ancestral to other hominids as well. Dave

And someone tell Marc to piss off out of this thread.. Dave

[Alas My Lo]

I guess it comes down to defining "obligate".

Gibbons & Homo are obligate bipedalists in compressional
locomotion. Fact.

Lucy shows evidence of occasional or habitual bipedal
compressional locomotion. Fact.

Thanks for responding. Dave

[Alas My Lo]

For the record, I didn't type that last line, it got copied
and not cut. Oh well. DD

[McLark]

<alas_my_loves@yahoo.com> wrote in message
news:1126646689.174407.51080@g47g2000cwa.googlegroups.com...
>I see that MCLARK "Good Humour Man" has shown up. Rather than
>wet or dry ape, I prefer "snow man".
>
> I'm from the prairies of Minnesota, "Land of 10,000 lakes",
> and 10 big blizzards, and the sea is far away.

Really? So am I. I hail from Windom, actually (although I
don't live there these days). Where are you from?

> The sentence you copied was in context of the paragraph,
> before you fragged it.

OK, how is ...

"Very long arms w/ short legs or very long legs w/ short arms
would strongly indicate obligate bipedalism IMO."
--"Alas_my_loves", 09/10/05

...taken out of context?

> The following is a copy of my first post to the AAT Group
> back in February.
>
> "MV: Does anybody know who is A. Lemak A.S.? He sent
> me this.
>
> Smithsonian mag. oct. 2001 article on Cheney & Seyfarth
> observing baboon troop wading quadripedally through
> ponds...photo...."Sylvia" (baboon mother) once made a long
> water crossing with her infant clinging to her belly. Since
> Sivlia herself could breathe, it did not dawn on her that
> her submerged baby couldn't, and as a result, it drowned at
> her breast.....Bipedal chimp mother wouldn't have that
> problem.
>
> Also..Readers Digest Amazing facts book...a Dr. Britton had
> put a single chimp "Bongo" on a small island. It snowed,
> Bongo would only walk bipedally on the soft snow...like
> marsh.."
>
> Freeze-dried ape.... voila..... dry ape. okeydokey? DD

God only knows what any of that means. But I can clearly see
that you've been contaminated by the Puttian bottlewasher. I
think he spells it "okidoki" (I could be wrong, I don't read
his stuff anymore --bad heart).
--
"You might be right but, people shouldn't buy it unless you
can *demonstrate* it through logical reasoning and/or
evidence and I just don't think you have done that." ---Algis
Kuliukas 08/14/05

[McLark]

<alas_my_loves@yahoo.com> wrote in message
news:1126650603.422426.219330@g49g2000cwa.googlegroups.com...
> Lucy's arms are longer than the overall length of her legs,
> though not as much as current apes.
>
> So, Lucy definitely shows neither gibbon-like or human-like
> obligate bipedalism. Her limb lengths remind me of spider
> monkey limbs.
>
> Ross: How could anyone look at this & not recognise the
> ancestral relationship between humans & australopiths? -
> http://www.anthro4n6.net/lucy/

Do you suppose you could use a newsreader that keeps track of
attribution? You know, those annoying little carets (>>>)?
Also, leave the header info in (like above) so that folks know
who said what and when. That will leave your post much more
readable and make it possible to keep ~some~ track of the
thread. I know Marco doesn't do any of that but that's because
he doesn't ~want~ people to follow his free association-like
pontifications.

> I don't disagree. But there may have been many very similar
> relatives, and I'm not sure that Lucy and other apiths
> weren't ancestral to other hominids as well. Dave
>
> And someone tell Marc to piss off out of this thread.. Dave

Marco doesn't listen to good advice. Nobody thinks it's funny
anymore....

--
"You might be right but, people shouldn't buy it unless you
can *demonstrate* it through logical reasoning and/or
evidence and I just don't think you have done that." ---Algis
Kuliukas 08/14/05

[Alas My Lo]

"... chimp "Bongo" on a small island. It snowed, Bongo would
only walk bipedally on the soft snow"

> Freeze-dried ape.... Eureka!..... dry ape. okeydokey?

Good Humor Man,

title of topic IIRC,

A *DRY* DISCUSSION ABOUT THE ORIGIN OF BIPEDALISM

Dyathink the origin of bipedalism is on the slopes of
Kilimanjaro? Isn't that sorta close to some of the fossils the
diggers have found? Maybe like the Ice man Oetzi in the Alps,
there's a frozen bipedal ape or two up there that will be
revealed when all the glaciers melt away. DD

[Marc Verha]

<alas_my_loves@yahoo.com> wrote in message
news:1126648159.228441.178390@o13g2000cwo.googlegroups.com...

>>> I've no doubts about apiths being occasional bipeds or
>>> even habitual
bipeds in compressional locomotion, but the word "obligate"
should only be used if proven. Very long arms w/ short legs or
very long legs w/ short arms would strongly indicate obligate
bipedalism IMO.

>> As in gibbons, resp. humans, you mean?

> Yes specifically, but true in other apes, apiths and Homo
> as well.

You mean great apes (very long arms, but rel.shorter (at least
P & G) than in gibbons) are no "obligate" bipeds? Lucy did not
have very long arms, in fact, its arms seem to have been
rel.shorter than in human pygmies.

>> Interesting thinking. Apiths had rel.short arms & legs.

> Yes. Possibly habitual bipedalists but not obligatory
> bipedalists AFAICT.
DD

OK.

>>> My opinion is that apiths were locomotive generalists,
>>> alternating
compressional bipedalism and quadrupedalism
(kwalk/fistwalk/palmwalk) and tensional bimanualism and/or
quadrumanualism as the feeding opportunity or environmental
condition arose. DD

>> Yes, most gracile apiths lived in swale/gallery forests
>> etc. I guess
they climbed arms overhead, often waded & also walked on 2
legs & perhaps regularly KWed. The robusts lived in more open
habitats & seem to have climbed less. KWing features have been
described esp. in the E.Afr.apiths (anamensis, Lucy, boisei),
but AFAIK, not in the S.Afr.apiths.

--Marc

[Marc Verha]

<alas_my_loves@yahoo.com> wrote in message
news:1126650603.422426.219330@g49g2000cwa.googlegroups.com...

> Lucy's arms are longer than the overall length of her legs,
> though not as
much as current apes. So, Lucy definitely shows neither
gibbon-like or human-like obligate bipedalism. Her limb
lengths remind me of spider monkey limbs.

Spider monkeys probably have rel.much longer arms & legs.
Lucy had arms no longer than in Hs, and legs no longer than
in chimps.

> Ross: How could anyone look at this & not recognise the
> ancestral
relationship between humans & australopiths? -
http://www.anthro4n6.net/lucy/

How could anyone not recognise here the ancestral relationship
between apiths & chimps?

> I don't disagree. But there may have been many very similar
> relatives, and
I'm not sure that Lucy and other apiths weren't ancestral to
other hominids as well. Dave

--Marc

[McLark]

<alas_my_loves@yahoo.com> wrote in message
news:1126732326.573100.38540@z14g2000cwz.googlegroups.com...
> "... chimp "Bongo" on a small island. It snowed, Bongo would
> only walk bipedally on the soft snow"
>
>> Freeze-dried ape.... Eureka!..... dry ape. okeydokey?
>
> Good Humor Man,
>
> title of topic IIRC,
>
> A *DRY* DISCUSSION ABOUT THE ORIGIN OF BIPEDALISM
>
> Dyathink the origin of bipedalism is on the slopes of
> Kilimanjaro? Isn't that sorta close to some of the fossils
> the diggers have found? Maybe like the Ice man Oetzi in the
> Alps, there's a frozen bipedal ape or two up there that will
> be revealed when all the glaciers melt away. DD

Ya know, the way I see it, you've got two choices: a). You can
clean up your act, get a decent newsreader and learn how to
use it, respect the process and take this thing seriously or
b). take a trip down that ol' plonk road. Your choice.
--
"You might be right but, people shouldn't buy it unless you
can *demonstrate* it through logical reasoning and/or
evidence and I just don't think you have done that." ---Algis
Kuliukas 08/14/05

[Rmacfarl]

<alas_my_loves@yahoo.com> wrote in message
news:1126651297.385276.76700@g44g2000cwa.googlegroups.com...
>I guess it comes down to defining "obligate".
>
> Gibbons & Homo are obligate bipedalists in compressional
> locomotion. Fact.
>
> Lucy shows evidence of occasional or habitual bipedal
> compressional locomotion. Fact.

Crap. Lucy shows incontrovertible evidence of obligate
bipedalism...

Ross Macfarlane

[Rmacfarl]

<alas_my_loves@yahoo.com> wrote in message
news:1126649369.146897.61600@z14g2000cwz.googlegroups.com...
> Ross: "Essentially they (gibbons) can't walk bipedally".
>
> I watched them walk bipedally, with hands raised in front of
> their trunk, at the local zoo. Though most of their time was
> spent sitting on a branch or brachiating, occasionally they
> would descend to walk 3 - 20 steps bipedally. I saw no
> quadripedal compressional locomotion. The only tripedal
> posture occurred when pivoting from seated to walking or
> vice versa, as humans do.

My mistake. I meant "Essentially they (gibbons) can't walk
quadrupedally".

Ross Macfarlane

>
> The adjacent spider monkeys (whose arms and legs are nearly
> the same length and prehensile tail is much longer) always
> walked quadripedally palmigrady in compressional locomotion,
> except when carrying food items (egg, apple) when they all
> switched to bipedal compressional locomotion. Dave

[Rmacfarl]

<alas_my_loves@yahoo.com> wrote in message
news:1126650603.422426.219330@g49g2000cwa.googlegroups.com...
> Lucy's arms are longer than the overall length of her legs,
> though not as much as current apes.
>
> So, Lucy definitely shows neither gibbon-like or human-like
> obligate bipedalism. Her limb lengths remind me of spider
> monkey limbs.
>
> Ross: How could anyone look at this & not recognise the
> ancestral relationship between humans & australopiths? -
> http://www.anthro4n6.net/lucy/
>
> I don't disagree. But there may have been many very similar
> relatives, and I'm not sure that Lucy and other apiths
> weren't ancestral to other hominids as well.

Which ones? You're not going to place yourself in the apes
froma'piths fringe are you?

Ross Macfarlane

[Rich Travs]

Marc Verhaegen wrote:
>
> "Rich Travsky" <" traRvEsky"@hotmMOVEail.com> wrote in
> message news:4323D05A.4DA569F6@hotmMOVEail.com...
>
> > How do we know Lucy walked upright? As in a modern
> > human's skeleton,
> Lucy's bones are rife with evidence clearly pointing to
> bipedality. Her distal femur shows several traits unique to
> bipedality. The shaft is angled relative to the condyles
> (knee joint surfaces) which allows bipeds to balance on one
> leg at a time during locomotion.
>
> This is ridiculous nonsense.
>
> In humans, the hip + knee + ankle *joints* are on 1 line.
> This is for stability, esp. when standing. Humans have
> femoral necks, see anatomy book. If the joints have to be on
> 1 line, there has to be a valgus knee ("shaft angles rel.to
> condyles"). If the femoral necks are rel.longer (as in
> H.erectus & Lucy), this valgus has to be greater. It has
> *nothing* to do with balancing.
>
> IOW, long fem.neck = very valgus.
>
> More interesting question:
> Q: Why did Lucy & H.erectus, more than H.sapiens, have long
> femoral necks (& hence needed valgus knees)?
> A: For femoral abduction.
>
> First consider this carefully, Travsky, before writing
> further nonsense.

This is ridiculous nonsense.

First consider this

http://www.anthro4n6.net/lucy/pelvis3.gif

before writing more nonsense.

[Marc Verha]

"Rich Travsky" <" traRvEsky"@hotmMOVEail.com> couldn't write a
sensible anwer in message
news:432CDB47.13D5C0E4@hotmMOVEail.com...
> Marc Verhaegen wrote:
> >
> > "Rich Travsky" <" traRvEsky"@hotmMOVEail.com> wrote in
> > message news:4323D05A.4DA569F6@hotmMOVEail.com...
> >
> > > How do we know Lucy walked upright? As in a modern
> > > human's skeleton,
> > Lucy's bones are rife with evidence clearly pointing to
> > bipedality. Her distal femur shows several traits unique
> > to bipedality. The shaft is
angled
> > relative to the condyles (knee joint surfaces) which
> > allows bipeds to balance on one leg at a time during
> > locomotion.
> >
> > This is ridiculous nonsense.
> >
> > In humans, the hip + knee + ankle *joints* are on 1
> > line. This is for stability, esp. when standing. Humans
> > have femoral necks, see anatomy book. If the joints have
> > to be on
1
> > line, there has to be a valgus knee ("shaft angles rel.to
> > condyles"). If the femoral necks are rel.longer (as in
> > H.erectus & Lucy), this
valgus
> > has to be greater. It has *nothing* to do with balancing.
> >
> > IOW, long fem.neck = very valgus.
> >
> > More interesting question:
> > Q: Why did Lucy & H.erectus, more than H.sapiens, have
> > long femoral
necks (&
> > hence needed valgus knees)?
> > A: For femoral abduction.
> >
> > First consider this carefully, Travsky, before writing
> > further nonsense.
>
> This is ridiculous nonsense.
>
> First consider this
>
> http://www.anthro4n6.net/lucy/pelvis3.gif
>
> before writing more nonsense.

[Rich Travs]

Marc Verhaegen wrote:
>
> "Rich Travsky" <" traRvEsky"@hotmMOVEail.com> wrote in
> message news:4323D25B.C3A949CD@hotmMOVEail.com...
>
> > > > > > You mention elsewhere that apiths (all spp. IYO?)
> > > > > > were obligate
> bipedalists. DD
>
> > > A lot of PAs keep repeating this without good evidence.
> > > What we do know
> is
>
> > WHAT????? The skeleton is conclusive.
> http://www.liverpool.ac.uk/premog/premog-research.htm
> http://www.anthro4n6.net/lucy/
>
> Sigh. As usual, you're not following. Once again. Try to
> follow, my boy. No difficult. Only requires a very little
> bit of logic.
>
> Why do PAs say apiths were bipedal? Because their hindlimbs
> bear resemblances not only to apes but also to humans.

You're not following. Pelvis, knee, foramen magnum add up
to bipedal.

Look at those pictures, particularly

http://www.anthro4n6.net/lucy/pelvis3.gif

The comparative data is clear.

okidoki?

> Short-sighted people like you reason like this: evolution
> was from apelike to apith to human, humans are obligatory
> bipeds, hence appearance of human-like features in apiths
> suggests they walked a lot. But the evolution was not
> ape>apith>H. It was HP-LCA>H & HP-LCA>P. Still following?
> Obviously most apiths were more like HP-LCA than like living
> H or like living P.
>
> IOW, that apith fossils show humanlike features (& apelike
> features & unique features) is to be expected: they lived
> 2-4 Ma, as you might know. This this does not mean they ran
> on 2 legs, only that they wer more primitive than living P
> or H. Humans are derived in 1 direction, P in another, but
> both had the same HP-LCA ~5 Ma.
>
> Okidoki?
>
> Now read further instead of interrupting with irrelevancies:
>
> > > that apiths (esp.graciles) had curved phalanges
> > > (branch-hanging) and (esp.E.Afr.spp) had knuckle-walking
> > > features. Bipedal gait is proved by
> the
> > > Laetoli footprints, but this is also often seen in
> > > chimps, eg, RJ Clarke 1999 "Discovery of complete arm &
> > > hand of the 3.3-Ma Australop skeleton
> from
> > > Stf " SAJS 95:477-480 "... In 1985, my thoughts
> > > concerning the arboreal nature of the Laetoli footprints
> > > led me to arrange with the Boswell
> Wilkie
> > > Circus for a male chimp & a female bonobo to walk
> > > bipedally over wet
> sand.
> > > The results were remarkable ... the timid female walked
> > > nervously,
> digging
> > > her toes in & with wide-spread big toe, the male was
> > > confident and
> tended to
> > > walk with his big toe most often close to the other toes
> > > (Figs 5, 6).
> The
> > > prints that he produced have a strong resemblance to the
> > > Laetoli
> footprints
> > > ..."
> > >
> > > > > > Why? Were their arms so short that they could not
> > > > > > habitually
> palmwalk
> > > or knuckle-walk or fist-walk? DD
> > >
> > > > > Arms were shorter relative to legs than chimps, but
> > > > > more
> importantly,
> > > the skull (foramen magnum), pelvis (bowl-shaped) & knee
> > > (valgus angle)
> of an
> > > australopith are heavily modified / derived in the
> > > direction of obligate bipedalism...
> > >
> > > That's nonsense:
> > > - For.magnum position in apiths overlaps with that in
> > > bonobos.
> > > - The apith pelvis had the iliac bones +- oriented as in
> > > ape pelvises.
> Ape
> > > pelvises are derived in having much higher ilia than
> > > monkeys, apiths &
> Homo
> > > (see, eg, the well-know illustrations of Schultz). IOW,
> > > the apith
> pelvis is
> > > simply primitive hominid.
> > > - A valgus knee is NO adaptation to bipedal
> > > cursorialism, to the
> contrary.
> > > It's an adaptation to a rel.slow gait (note Hs has less
> > > valgus knees
> than He
> > > & apiths), with good lateral abduction of the femora:
> > > the laterally
> flaring
> > > ilia & the long femoral necks were adaptations for
> > > femoral abduction,
> and
> > > when the leg joints have to be on 1 line (hip, knee,
> > > ankle), a valgus
> knee
> > > is necessary (humans have less valgus knees & shorter &
> > > less horizontal femoral necks than erectus & apiths).
> > > - "Derived in the dir