Re: Becoming altricial/bi
J. Moore (j#d#.moore@canrem.com)
Sat, 7 Oct 95 18:35:00 -0500
Pa> Paul@crowleyp.demon.co.uk "Paul Crowley" writes:
Pa> > A) Your contention that children during the transitional phase
Pa> > could not grasp is not just unproven, but actually rests on
Pa> > assumptions that are false, and which Alex Duncan has already
Pa> > pointed out to you.
Pa> You are using all the discreditable tricks of an academic defending a
Pa> lost position. Please don't. It is too obvious and just wastes
Pa> everyone's time.
Pa> (a) I have not referred to children, but to infants under a year (or as
Pa> I offered for your preference) under three months.
Okay:
A) Your contention that infants during the transitional phase
could not grasp is not just unproven, but actually rests on
assumptions that are false, and which Alex Duncan has already
pointed out to you.
Pa> (b) If you want to assert that I made "false assumptions", please state
Pa> what they are yourself, instead of vaguely referring to someone else's
Pa> postings.
If you didn't bother to read Alex's post, you certainly won't
read mine.
Pa> > Hominids even later than the transitional
Pa> > population retained quite good climbing, and therefore grasping,
Pa> > abilities, despite your unsupported claims to the contrary.
Pa> (c) I have never suggested or implied that hominids lost "good climbing
Pa> abilities" or "grasping abilities". I stated solely that an infant with
Pa> a bipedal foot could not *cling* to its mother in the same way as the
Pa> infants of the CA did.
Since those hominids, as Alex pointed out to you, had feet which
showed good grasping and climbing abilities, and this means an
ability to cling, your unsupported statement is a "claim to the
contrary".
Pa> > B) Even if the transitional hominid child couldn't grasp as well
Pa> > as a chimp of the same age, this would not be a special problem
Pa> > for a bipedal mother as it would be for a quadrupedal mother.
Pa> Why bring in such a comparison? Would the word "smokescreen" be
Pa> appropriate?
I suppose the word "smokescreen" accurately describes what you're
trying to do here. I commend you for being so honest about it.
Pa> > Whereas a quadrupedal mother in that circumstance would be forced
Pa> > to adopt an awkward stance most of the time, no specially
Pa> > different stance would be needed for a bipedal mother.
Pa> > In fact, this would tend to reinforce bipedal abilities.
Pa> How about a discussion of the problems of a spider if it's young did or
Pa> did not have grasping ability?
You seem to be insisting that I am out of line in pointing out that
a population of bipedal infants would be expected to have bipedal
parents. The mother of a bipedal child being herself bipedal is
hardly a great mental stretch. I suppose you don't want to talk
about it because it negates the problem of carrying an infant,
even if that infant didn't have good grasping abilities. However,
since we can see that the period when our infants began going
through a longer post-natal development period is many millions
of years after the transition from CA to hominid, even that
contention is unlikely to be true. You have not attempted to
support it in any way.
Pa> > Pa> The bipedal hominoid mother could not have spent the altricial
Pa> > Pa> period in
Pa> > Pa> the trees. Nevertheless she had to have a safe "home base".
Pa> >
Pa> > Pa> Please respond to these last two sentences.
Pa> > Pa> Paul.
Pa> >
Pa> > Neither point makes any sense. They are simply unsupported
Pa> > claims which depend on your contention, contrary to paleoanthro
Pa> > evidence, that transitional hominids did not retain climbing
Pa> > abilities, and that for millions of years, the one organ which
Pa> > didn't develop during the longer infant development period was the
Pa> > brain.
Pa> These are not my contentions - as you are well aware. I fully agreed
Pa> with your statements of fact about brain developments; the fossil record
Pa> is not contentious.
But they *are* your contentions:
If early hominids retained good climbing abilities, they
certainly could have spent time in trees, yet you claimed --
without support of any kind -- that they couldn't. So your claim
required that "transitional hominids did not retain climbing
abilities". However, it should also be noted that evidence from
observations of chimpanzees shows that this climbing ability would
not be needed for predator defense, although it's a likely enough
nighttime habit for that population.
If you "fully agreed" with my statements about brain development,
then you see that the period we became altricial was the period
when we see longer post-natal infant development, and a large
degree of brain expansion -- 2.5 to 1.5 mya. If, as you insist
(again without any support), this period when infants underwent
longer post-natal infant development happened millions of years
before, your claim requires that "for millions of years, the one
organ which didn't develop during the longer infant development
period was the brain".
Jim Moore (j#d#.moore@canrem.com)
p.s. The fossil record is not contentious, but interpretations of it
often are.
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