Re: More Morgan/Nicholls
Phillip Bigelow (n8010095@henson.cc.wwu.edu)
Sun, 8 Jan 1995 07:51:51 GMT
Phil Nicholls writes:
>> Recent dating techniques are pushing the times (of
>South African fossils) back...
And then Elaine Morgan responds:
>Okay. And recent discoveries are pushing the times of
>the Afar fossils back even faster. It still seems likely
>on balance that the initial trigger of speciation was
>some environmental factor in Afar rather than in the far
>South.
Slow down; both of you. You both are forgetting that taphonomy plays a
role in where these fossils are found in the first place. Both the Afar
region and the area where the Taung baby was found are _structural
depressions_. They are depositional basins. Depositional basins are where
fossils occur. That leaves out roughly 70% of the African continent where,
because it was an erosional source, we will never know _what_ lived there.
Presently, the mountain gorilla has a habitat that is far from any
depositional basin; hence, if the mountain gorilla was extant during the
Pliocene, we would never know of it's existance. Never. The same goes for
fossil hominids. We will never know whether Afar or Taung were _preferred_
habitats for hominids. All we can say for certain is that these basins were
_TOLERATED_ by hominids. That's it. To claim that these hominids _liked_
these areas is pure speculation. Pure dreaming. They may have liked Afar
and Taung, but, how can we know?
My feeling is that, with over 70% of the African continent lacking
Mio-Pliocene sediments, the speciation of hominids could just as
parsimoniously have occurred someplace _other_ than Afar and Taung. Ms.
Morgan, I think it is very unwise of you to make a claim of speciation
occurring in Afar, based only on the _presence_ of fossils in that area.
Statistically, the vast unpreserved parts of Africa may have been the
localities for the initial speciation.
<pb>
Ms. Morgan continues:
>> All known hominids are found in mud and silt deposits
>that border what at the time were savannahs.
>The same is true of all known hippopotamids. Isn't that
>interesting? (But "savannah" was not how Johanson
>described Lucy's habitat. "Lush", he said.)
Indeed. Whatever "lush" means. :) Johanson is guilty of the same
discretion as the AAT supporters are: not defining terms they use. "Lush"
could mean anything from a jungle on one extreme, to a ripparian habitat on
a savannah on the other extreme. "lush" typically means "heavy vegatated".
That could apply to many environments.
<pb>
Elaine Morgan continues:
>RE: Diving adaptation. I forget who said that this was
>rubbish.
> But: The striking capacity humans share with all diving
>mammals and all diving birds is conscious control of
>breathing. A dolphin can be trined to respond to a
>command to retrieve different specified objects from
>different depths in a training tank or pool. The amount of
>air it inhales varies according to the amount of time
>it knows it will need to be underwater.
> Humans have the same kind of volitional breath control.
>Apes do not. That is the sole reason why it is virtually
>impossible to teach them vocal language however adept
>they become at sign language.
Couldn't this also mean that, because humans and dolphins both have
large brains, that they have the _capacity_ to afford to possess conscious
control of breathing? In other words, the _brain_ is the reason; _not_ the
fact that the dolphin is aquatic. Sorry. I have this nasty habit of
comming up with alternative explainations.
<pb>
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