Kortlandt's Observations and the Emergence of A'piths

As I indicated in a recent post on SAP--
http://makeashorterlink.com/?R5D525D65
--I think Kortlandt's 
observations are very important.  But I think people 
miss the full significance of Kortlandt's observations, 
especially when it comes to some of the comparisons 
Kortlandt made with respect to differences in savanna 
chimps (seasonal habitat chimps) and bonopos 
(seasonless habitat chimps).  


What follows was cut and pasted from the post(s) at the 
following link:
http://makeashorterlink.com/?M5C435D65


*********** Begin cut and paste *********************

J. Moore said:
During the 1960s Dr. Kortlandt, a Dutch researcher, did a number of
experiments with wild chimpanzees in natural populations in Africa.  
One of these was to see how different populations of chimps react to
predators.  To do this, he used a stuffed leopard dummy with 
electrically moveable head and tail.  A baby chimpanzee doll was placed 
in the leopard's front paws and the dummy was placed where it would be 
encountered by mixed groups of chimpanzees, including females with young, 
in all the experiments.  Several populations of chimpanzees were so 
tested several times, including groups in two different jungle areas,
and a group of savannah woodland chimpanzees.  All the chimp groups 
reacted by picking up sticks as clubs, breaking small trees and tree 
limbs to use as clubs, and throwing these at the leopard dummy.  An 
interesting difference emerged between the jungle chimps and the 
savannah chimps.  The jungle chimps, while aggressive toward the
leopard, were uncoordinated in their attacks and when throwing objects, 
never actually hit the leopard.

Dr. Kortlandt observed:
  "The results with savannah chimpanzees, however, were quite different.
They grabbed the largest of the available clubs, which was 2.10 m long,
and they tore down small trees of about the same length; they slashed
viciously at the leopard with these.  With the aid of the film we made,
we could measure impact velocities of approximately 90 km/h, which would
have been sufficient to break the back of a live leopard.  In addition,
there was teamwork in evidence during these attacks, again in contrast
to what we observed in the jungle chimpanzees.  During the final attack
the dummy was encircled by five chimpanzees, while two others stood in
readiness at some distance, in case they should be needed.  Then the
leader grabbed the tail of the leopard and ran away, tossing the
predator so that the head flew from the body.
  "A side effect of the experiment was the observation that the savannah
chimpanzees more often walked erect than do the jungle chimpanzees."

*********** End cut and paste *********************


Jungle chimps, who reside in seasonless rainforest habitat, 
are relatively ineffective--less accurate and lower 
velocity to their rocks/sticks--and incompentent at rock 
throwing and stick wielding.  Also, They are relatively less 
cooperative and less coordinated in their collective rock 
throwing and stick wielding attacks: IOW, they aren't very 
good team players.  And, they are less bipedal or, at 
least, they don't walk erect as often as do the savanna 
chimps.

Savanna chimps, who reside in habitat that is seasonal, most 
notably with respect to the fact that it contains a 
significant, if not especially severe, dry season, are more 
effective and competent--more accurate and higher velocity 
to their rocks/sticks--at rock throwing and stick 
wielding than are jungle chimps.  They are also relatively 
more cooperative and coordinated in their collective attacks 
than are jungle chimps: IOW, in comparison to jungle chimps, 
savanna chimps are pretty good team players.  And savanna 
chimps are more bipedal or, at least, they walk erect more 
often than do savanna chimps.

To this I'd like to add one more observation:
Humans/hominids are more effective and competent at rock 
throwing and stick wielding than are even the best savanna 
chimps (could a chimp throw a 90 mph fastball over home 
plate?).  Humans/hominids are more cooperative and 
coordinated in their attack behavior than are even the most 
cooperative savanna chimps: in other words, humans/hominids 
are especially good team players.  And, humans/hominids are 
obligate bipeds.

Conclusion:
What is the determining factor here?: the seasonality of 
the habitat/environment/climate.  IOW the reason hominids 
emerged is because their bipedal ability to employ team 
oriented rock throwing, stick wielding, attack behavior 
makes them better able to survive the selective 
implications associated a habitat/environment/climate 
characterized be severe seasonal dessication.  More 
precisely, IMO, the reason hominids emerged has to do with 
the supposition that apes that are more bipedal and that 
employ more team oriented attack behavior and that are, as 
a consequence, better able to maintain territorially 
situated resources and, as a consequence, better able to 
maintain team oriented cooperation to keep predators at bay 
will have had a very significant selective advantage over 
those that are less proficient at the same.

How might this thinking be tested:
1) Savanna chimps should display more communal 
territorialistic behaviors than do jungle chimps
2) Savanna chimps should be more sexually dimorphic (and 
male dominated) than are jungle chimps.
3) Savanna chimps should display higher degrees of humanlike 
intelligence than jungle chimps.
4) We should expect to find paleoclimatic and fossil evidence 
of homids having emerged in a manner temporally and 
geographically correlated with the onset of severe seasonal 
dessication--monsoon habitat/environment/climate. 

Is there a competing hypothesis in any of this?  For example, 
a quick reading of Kortlandt's thinking (and J. Moore's 
thinking) in the link above might leave some with the 
impression that the difference can more correctly be 
correlated only to differences in predation pressures between 
savanna habitat and jungle habitat and, therefore, my 
hypothesis which focusses on seasonal dessication and communal 
territorialism in addition to predation is uncalled for.  But, 
I contend, a more careful reading of Kortlandt 
disputes/refutes this supposition.  Would anybody like to 
dispute this supposition?


Jim
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