Re: An alternative to ST and AAT

Gerrit Hanenburg (
Thu, 21 Nov 1996 11:54:34 GMT

"John Waters" <> wrote:

>Harvey,P.H.and Clutton-Brock,T.H.(1985). Life History
>Variation in Primates. Evolution 39:559-581.

>JW: Phew. Just as well I didn't forward my information to
>Roh. In the well known *science* journal National
>Geographic Vol 168, No. 5 (1985), it is reported that an
>exhaustive investigation by Alan Mann of the University of
>Pennsylvania indicated an average life span for A.
>africanus of 22 years.This was based upon a study of teeth.

>What do you make of that, Gerrit? I know your figure is an
>average for all types of australopithicenes, but this is a
>huge difference. How can the experts make such enormous
>mistakes? (Assuming it was a mistake).

As Phillip already said you shouldn't consider them as mistakes but as
different hypotheses.
Female bodyweight in primates is fairly strongly correlated with
maximum lifespan (r=0.78),but there will always be some scatter around
a regression line depending on how strong the correlation is. Some
species will be closer to the line than others.
For example,the predicted lifespan of Pan troglodytes (female
bodyweight=31.1kg) is 43.0 years,while the actual lifespan is 44.5
years. That is a close fit (d%=3.5). For Hylobates lar
(bodyweight=5.3kg) the values are 25.7 and 31.5 respectively
Also keep in mind that the value from the regression equation is a
prediction of *maximum* lifespan not average.