Re: Becoming altricial/bi

J. Moore (
Mon, 9 Oct 95 23:05:00 -0500

Pa> In article <>
Pa> "J. Moore" writes:

Pa> <A lot of convoluted and obscurely worded prose - which is so
Pa> uncharacteristic that extraneous reasons must be supposed>

That would be the prose wherein I had to point out to you that a
bipedal hominid infant would be expected to have bipedal parents.
Such an obvious point, really, that I find it surprising that you
had to have it pointed out to you. Still more surprising that you
found this convoluted and obscure:

JM> You seem to be insisting that I am out of line in pointing out that
JM> a population of bipedal infants would be expected to have bipedal
JM> parents. The mother of a bipedal child being herself bipedal is
JM> hardly a great mental stretch. I suppose you don't want to talk
JM> about it because it negates the problem of carrying an infant,
JM> even if that infant didn't have good grasping abilities.

Pa> Let me just focus on this statement:

Pa> > then you see that the period we became altricial was the period
Pa> > when we see longer post-natal infant development, and a large
Pa> > degree of brain expansion -- 2.5 to 1.5 mya.

Pa> Do you accept:
Pa> a) that bipedalism can be dated before 3.0 mya?

This is known.

Pa> b) that bipedalism, _on_its_own_, requires a degree of
Pa> maternal care for the hominid infant which is quite different and far
Pa> in excess of that needed by the pre-bipedal infant?

Different? Insofar as the predominate mode of locomotion is
different, and the infant would be initially carried in front of
the mother rather than behind, yes. This would tend to promote early
mother-child teaching-learning (and probably parental bonds) to a
somewhat greater degree than seen in chimps. This early period,
until walking began, would not at first be as long as seen among
modern humans, however, because the longer infant development
period didn't come up until about 2.5-2 mya. So as to "far in
excess", I would have to say no. There is no reason to think it
would be appreciably in excess of what chimps go through; their
young are quite dependent on their mothers until 5 years old.
"Orphaned chimpanzees at Gombe or Mahale rarely survived if under
five years of age at the time of the mother's death." (Caroline
Tutin 1994:188, in *Chimpanzee Cultures*, Harvard U. Press).

Pa> c) that when bipedalism was first established the mother/infant
Pa> pair could not have normally slept in the trees?

Of course they could have. Hell, WE can do it, and they had feet
that were demonstrably better adapted to grasping and climbing
than ours. Alex has pointed this out to you several times.

Pa> d) that prior to the use of fire, hominids could not normally
Pa> have slept on open ground?

Of course they could have. Chimps can do it; why couldn't early

These things have been pointed out to you before. Continuing to
bring them up as if they hadn't makes you look foolish.

Jim Moore (

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