Re: Becoming altricial/bipedal

Alex Duncan (
11 Oct 1995 00:56:18 GMT

In article <> Paul Crowley, writes:

>You can normally sleep in the trees? Naked? Holding onto a naked six-
>month infant? And looking after say a 2-year old and a 4-year old?
>For twelve dark, bitterly cold, hours every night in the African
>mosaic/savannah? Wow! Tell me how. Or quote me the reference.

There are 2 problems with this. 1) We have no reason to suppose that
the earliest hominids were hairless. When functional nakedness arose
must unfortunately be somewhat of an educated guess. Most educated
guessers are guessing that functional hairlessness didn't arise until the
appearance of H. erectus.

2) It is unlikely that an early hominid individual with a 6 month old
infant would also have a 2 year old and 4 year old to look after. If we
follow a chimp (or hunter-gatherer human) model, there is no reason not
to assume that females would have experienced lactational amenorrhea for
3 to 5 years after birth. In other words, for a female hominid with a 6
month old child, the next youngest child would probably be at least 4
years old (if not older), and thus quite capable of negotiating the trees
on its own.

Alex Duncan
Dept. of Anthropology
University of Texas at Austin
Austin, TX 78712-1086