Re: An alternative to ST and AAT
Thomas Clarke (clarke@acme.ucf.edu)
22 Nov 1996 04:36:55 GMT
In article <3293BA63.3C4A@scn.org> Phillip Bigelow <bh162@scn.org> writes:
>Thomas Clarke wrote:
>> In article <328E8796.2B2E@scn.org> Phillip Bigelow <bh162@scn.org> writes:
>> > Thomas Clarke wrote:
>> > > If some primates had developed bipedalism 10 or 20 million years ago,
>> > > bipedalism like that practiced by Australopithecenes and Hominids, then
>> > > the did not evolve very far along an evolutionary trajectory similar
^^^^
>> > > to A/H or else we would come across ancient artifacts (fossil artifacts?).
>I responded:
>> > Not definatively. There is no gaurentee that a
>> > low-population, geographically-isolated, delicate species of
>> > bipedal primate would be found as a fossil. Given enough
>> > time searching, the odds stay pretty much the same as they were
>> > when one began searching for the fossils.
>> But that was my point.
>No, that wasn't your point at all. Read what you wrote at the top
>of this post. You claimed that IF a bipedal primate
><other than one of our lineage> ever existed in the past, it would
>necessarily have already been discovered and dug up.
>Read your response through carefully, again.
You missed the word "very". If it had evolved as far as man, then
it would be detectable; that is clear (to me at least).
As I try to weasel out, we can debate the meaning of "very"
and whether I originally menat as far as the the equivalent of
Australopithecenes or as far as the equivalent of Homo habilis
or as far as ... Or whether I am trying to change what I meant
by "very", but
I did not claim that IF a bipedal primate had existed inthe
past that it must be detectable.
>I earlier wrote:
>> > This subject is getting into the science of "taphonomy", Tom,
>> > and it involves probabilities, sedimentation rates, basin-analysis,
>> > pH of the sediment, numerical abundance of the hypothetical
>> > species, erosion rates, geographical range of the hypothetical
>> > species, re-working of the material, and lastly, this question:
>> You are making it too complicated again -
>Well, gee.... Sorry that I had to drag the conversation *up*
>to a higher level of discourse. I promise I won't do that
>again, Tom! :-)
It was not needed. My point, trite as it may have been was
about artifacts as I have been amply corrected. Does taphonomy
apply to artifacts?
>> Granted, though that a species equivalent to Neanderthals might well
>> be missed had such developed millions of years ago.
>A taphonomist would counter by pointing out to you that the FACT that
>Neanderthal fossils have been discovered STRONGLY indicates that
>these creatures were numerically-abundant. It harkens back to what
>I wrote earlier(above) about population-number being an important factor
>regarding whether a hypothetical species will ever be found as a
>fossil in the first place.
Do taphonists worry about selection effects? There is one kind of
fossil that Homo sapiens is particulary interested in - man-like fossils.
Thus a man like fossil of lesser frequency would be more likely to
be discovered than a non-man-like fossil. Just curious, I know
astronomers have to be very wary of selection effects in their
statistics.
>I earlier wrote:
>> > "Do species that inhabit mountainous terrane have a REASONBLE
>> I don't remeber bringing up mountain primates...
>You didn't. I was countering your (baseless) claim that if an
>organism existed in the past, it WOULD HAVE been found. I offered you
>a counter-scenario in which, lacking a sedimentary basin to preserve
>the fossil, a hypothetical mountain primate of 5 million years ago
>has a snowball's chance in hell of being found. Man... you need to
>do a little reading in sedimentology and taphonomic processes.
As I said, I did not make that claim. Maybe that is why I didn't
understand where the mountain primates came in.
>I wrote:
>> > The correlary is that there is always a possibility that other,
>> > now-extinct bipedal primates of another clade existed. Proving
>> > it is an extremely difficult proposition.
>> Sure. But that is a scientifically unprovable possibility.
>That was the point I was making to YOU. Remember, YOU were the
>one who claimed that if a bipedal primate other than a hominid
>existed, we surely would have discovered it.
I, I reiterate, did not make that claim. You misread what I said.
>I was just pointing out to you that you can't make that claim, and
>remain credible.
Never did. Never would. It wouldn't be logical.
Tom Clarke
|