On Sat, 05 Jul 1997 22:10:04 -0500, Glenn Morton wrote:
[...]
GM>As I have noted many times, Jim, a small population of humans
>could survive for millions of years
Why would this "population of humans" (ie. Australopithecines)
remain "small" "for millions of years"? My understanding is that
"small" populations invariably go extinct. The farming motto
applies: "Get big or get out"!
GM>in a tropical jungle and leave no trace of themselves.
Why would they remain "for millions of years in a tropical jungle"?
Besides, my understanding is that Africa has not been "tropical
jungle" for the whole 5.5 million years:
"Current evidence suggests that about 3.0 to 2.4 million years ago
(mya), the relatively cool, dry climate of tropical Africa presented
challenging new conditions for woodland-dwelling Australopithecus.
In theory, the cooler climate cleared out some of the woodland to
form new open habitats. It is at about this time that the earliest
species of the genus Homo emerged, between 2.5 and 2.0 mya, to
exploit the new habitats as a rather aggressive omnivorous
scavenger." (Larick R. & Ciochon R.L., "The African Emergence and
Early Asian Dispersals of the Genus Homo", American Scientist, Vol.
84, No. 6, November-December 1996, p539).
Note from the above that the latest thinking is that "the genus Homo
emerged, between 2.5 and 2.0 mya".
GM>This is because the acidic soils dissolve the skeleton in about 1
>year.
Could you cite references to this? Encyclopaedia Britannica has a
lot on African soils but nowhere does it mention that the
jungle soils were "acidic"
Also, if the African "jungle" "soils" were "acidic", then there
should be *no* fossils from that area for the last 5.5 my. Is that
so?
Stanley attributes the lack of 8-4 mya Hominidae fossils to rare
sedimentation and lack of study:
"Early apes in Africa and Asia Although an extensive Plio-
Pleistocene fossil record has been uncovered for the Hominidae, very
few known fossil remains of any age represent the Pongidae.
Furthermore, the fossil record of the superfamily Hominoidea in
latest Miocene and earliest Pliocene time (8 to 4 million years ago)
is almost entirely barren. Sediments representing this interval in
Africa, where apes and humans may have evolved, are rare and poorly
studied." (Stanley S.M., "Earth and Life Through Time", 1989, p575)
GM>Because of this, there is absolutely NO fossil record of
>Chimpanzees or Gorillas. The oldest chimp skeleton is about 400
>years old, yet we know they lived on early longer ago than 400
>years.
Have you got a reference for this? Stanley's statement aboveseems
to indicate an adequate Hominidae fossil record from 4 mya on?
In any event, the differences here is that "Chimpanzees" and
"Gorillas" don't use tools. If "a small population of humans" did
"survive for" 5.5 "millions of years in a tropical jungle" they
would "leave" some "trace of themselves" in the form of stone tools.
Assume a constant population of 100 adults, with a generation length
of 55 years. That is 100,000 generations. Assume further an
average of 5 stone tools per adult per lifetime. These are
deliberately conservative estimates. There would probably be
thousands of adults if the species had survived for 5.5 million
years. You claimed the Tasmanian aborigines had 24 tools, but I am
assuming only 5. The generational length might have been shorter or
longer. Multiplying this out makes 100 x 100,000 x 5 = 50,000,000
stone tools!
No doubt you will claim that for the whole 5.5 mya the
"technological dark age" was so bad they used wooden tools!
GM>The fact that Homo erectus was quite widespread when they first
>appear, says that they lived a long time before this.
How did "Homo erectus" get into the act? This "small population of
humans' started of as Australopithecines. Are you claiming that
they evolved into "Homo erectus" while in this "tropical jungle'?
Why would that happen in the relatively constant environment of "a
tropical jungle", when it is a climatic change from
"tropical-woodland" to "open savanna" that is supposed to have
stimulated the evolution of Homo erectus from Australopithecus:
"Evolution of the genus Homo from Australopithecus seems to be
linked with global climate changes between 2 and 3 million years
ago. Cooler temperatures diminished the tropical-woodland habitat
of Australopithecus in favor of more open savanna. Several species
of Homo evolved rapidly to occupy these new habitats, as did
Paranthropus, another descendant of Australopithecus. Paranthropus
became extinct by 1.2 million years ago. Early Homo maintained a
generalized anatomy as it spread throughout tropical and subtropical
Asia, but apparently became specialized with the evolution of Homo
erectus by 1.8 million years ago." (Larick R. & Ciochon R.L., "The
African Emergence and Early Asian Dispersals of the Genus Homo",
American Scientist, Vol. 84, No. 6, November-December 1996, p540)
God bless.
Steve
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