Re: Missing Link (was Human Chimp Gorilla)
Stanley Friesen (sarima@ix.netcom.com)
Sun, 28 Jul 1996 03:16:25 GMT
Sorry about the delay in responding - I have been busier than I
expected.
Mike Muller <muller@flmhh.ufl.edu> wrote:
>These examples are not dealing with the morphocharacters possess by the
>classic erectus holotype of keeling, TMJ shape, torus shape and position
>of brain, and occipital characteristics. Which the African material does
>not possess.
The reference I cited - Rightmire's _The Evolution of Homo erectus_,
disagrees with this statement. On page 236 (of my edition) he
discusses a "diagnosis" of _Homo erextus_ that mentions torus
morphology, frontal keeling at the very least as being diagnostic of
that species. He follows this with the statement "_Homo erectus_ as
defined in this way is known from Indonesia, China, northwest Africa,
and the sub-Saharan region." Furthermore, he discusses keeling in the
specimen KNM-ER 3733 earlier (this just from a quick scan of the
index, and a cross-check wih the text).
[Also, the comparisons I cited before were only a small selection of
the large series of comparative grphs in chapter 6]
>
>> I suspect that African H. erectus came *from* Asia. ...
>> How can this be? Simple - new species tend to arise in small
>> peripheral populations ... In fossil contexts this
>> is called "Punctuated Equilibrium".
>
>I think tht Gould would take exception to that definition!
>
Actually, he said so himself in one of his essays in "Natural
History"! Specifically he stated that PE is based on Ernst Mayr's
speciation model as viewed from a geological time perspective.
I just filled in the details.
>
>> Simply put, I would guess that the origin of Homo erectus was a
>> punctuation event - a rapid evolutionary transition, taking probaly no
>> more than 25,000 years (1,000 generations). Note, this is rather less
>> than the *uncertainties* in the dates of the earliest Asian H.
>> erectus!! This means that the appearance of H. erectus would be
>> virtually instantaneous, fossil-wise.
>
>The newest Ar/Ar dating of Asian materials is not uncertain and giving
>sound dates for classic erectus from 1.8 on the Mojokertoand the
>thermoluminescence dating is providing dates to much less than 100,000
>for the Ngandong materials.
And, as I said, speciation takes less than one quarter of that span.
[And if the date is cited as "1.8 Mya" then is *is* uncertain to the
tune of aout 100K. It would have to be cited as "1.80 Mya" to have a
*hope* of being in conflict with rapid speciation of the sort I am
talking about - and even then uncertainties as high as +/-15,000 are
possible, I would need to check the original sources for specific
citation of levels of uncertainty -- NO dates are absolutely certain,
all have at least some scope of uncertainty].
The peace of God be with you.
Stanley Friesen
|