Re: Postural bipedalism may have preceded and not causally connected to walking.

McGinn wrote:

> > > ` An animal that regularly is singled out by jaguars (or jaguar-like
> > > ` predators of the late miocene and pliocene) must be capable
> > > ` of facing them down and/or even wrestling with them
> > > ` occasionally.
>>>
>> Not so. Baboons regularly harass leopards.
>> Predators cannot afford significant wounds,
>> and will avoid confrontation if there is any
>> likelihood of them,
>
> You're not contradicting anything I've said AFAICT.

Of course I am. Baboons don't have 'upper body
strength' -- and if they got into a "wrestling match"
with a leopard, there would be only one winner.
All they have are long canine teeth. A leopard
could easily defeat a single baboon, but two or
more could inflict serious wounds upon it, and
that would, in effect, be the end of the leopard,
since it would not be able to hunt. So baboons
can and do drive off leopards.

>> weapons that can inflict them -- and long,
>> strong canines being the most common. As
>> soon as early hominids learnt to use pointed
>> sticks, they no longer needed large canines.
>
> This is silliness. They started to poke at predators with pointy sticks.
> This is nonsense.

A group of hominids with pointed sticks (i.e.
spears) would defeat a leopard . . or even a lion.
Some rocks would also be handy.

> > > ' This requires
> > > ` the maintenance of strength in the upper body.
>
>> Nonsense.
>
> This isn't even controversial, you idiot.

You are the only idiot I have ever seen
proposing this. It's nuts.

>> > Well, this is similar to Crowley's predator free islands. The first
>> > problem with this is that it is extremely farfetched with respect that
>> > it requires unusual situational factors.
>
>> It requires the factors we see around us in
>> plenty today. An island like, say, Zanzibar
>> or Borneo -- and that's all.
>
> Extraneous nonsense based on your ignoranced based notion that geographic
> isolation is the engine of speciation. You seem blissfully ignorant of what
> an amateurish and unsophisticated approach you have assumed.

You have to find 'theoretical' reasons for
ignoring my arguments.

>> > The second problem is that there is no benefit to becoming
>> > bipedal in the scenario.
>
>> Eh? Those apes on the island that become
>> bipedal can live where there are no sleeping
>> trees, carry weapons, and wipe out all those
>> that don't. What better advantages do you
>> think there can be?
>
> They couldn't do this quadrupedally? Chimps currently fight each other
> without weapons. Not much incentive for such a tremendous shift in
> morphology. This is hardly better than AAT logic.

The first hominids fought with weapons.
That was why they could not be quadrupedal.

>> > Lack of predators also means a lack of a very important
>> > selective factor
>
>> The (temporary) absence of predators allows
>> a drastic change in niche, since the constraints
>> that had enforced stasis for millions of years
>> are (briefly) removed.
>
> Why bipedalism and other hominid traits?

Carrying weapons is not compatible with
tree-living. So tree-living has to end first.
That is only possible in the absence of
predators.

> Where's the selective factors? We're supposedly suppose
> to believe that once the obstacles are remove then
> human evolution is inevitable.

Not so. But it is necessary to remove the
obstacles first.

>> > (not to mention lack of ability to explain the
>> > fossil evidence which indicates A'pith being preyed upon by large
>> > felines).
>
>> When the newly-bipedal apes return to the
>> mainland they will, of course, occasionally
>> be preyed upon -- especially when they leave
>> the confines of their protected home sites.
>> Famine, war, and the routine dispersal from
>> successful expanding populations will all
>> result in susceptibility to predation.
>
> Extraneous nonsense. Paul, your model is contrived.

What is 'contrived'. Don't islands like Zanzibar exist?
Haven't such islands been a very common
throughout geological history?

>> > At best it still leaves open the question of what benefit
>> > did they recieve as a result of becoming bipedal.
>>>
>> The new species became able to exploit a niche
>> not before previously occupied, in sites formerly
>> not available to apes: sites without sleeping
>> trees, but defensible against predators.
>>
> This couldn't be achieve quadrupedally?

No. The ability to use weapons and tools
(and even carry rocks over distance) is not
compatible with quadrupedalism.

>> The idiotic standard-PA 'theory' (and the one
>> to which you subscribe) extraordinary new taxon
>> came into existence to exploit EXACTLY the SAME
>> sites in the SAME habitat in the SAME way as its
>> ancestral species!
>>
> Surreal. Your ignorance is overwhelming.

You don't say how. You can't say how.
But what else is new?

>> The "considerable and obvious benefit"
>> was that which drives ALL evolutionary
>> change: the ability to live a new form of life
>> (often in a set of new locations).
>>>
> Vague nonsense.

What is vague? You asked a question;
I answered it.

> No duh. Paul, Jason's right, your arrogance inspired ignorance renders you
> feckless.

One way to be sure you're right is to find
when you and Jason are in agreement --
and pick the opposite. It would be next
to infallible.


Paul.




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