On Tue, 22 Oct 2002 09:29:49 -0700, Jeff Keller
<[log in to unmask]> wrote:

>Did the first Homo sapien appear during a glacial, intraglacial period?  Or
>did they appear in Africa where it would not matter? Or are we even
>considering just Homo sapien? Are we going back farther through dozens of
>ice ages and pre-Homo sapien species?

It appears as the developement of Homo Sapiens *started* with it's first
predecessors (australopithecines) with the first ice age, but in Africa.
After 2 mio years ago. Out of predecessor primates who lived 30 million
years in an all frugivore lifestyle.

In the 2 mio years of "ice age" frequent changes occured between glaciation
and interglacials. Interglacials would bring a climate like today to the
north (Europe) and bring the rainforest back in africa.
Interglacials were shorter than glacials, but all several 1000 years long.

Ice age resulted in dry climate which pushed back the tropical rainforests
so that a savannah open forest developed.
Some primates adapted to this open woodland they were bipedal, upright,
small-brained and still able to climb well. Our "anchestors".
It seems they were sleeping or hinding away from the predators up to the
trees. Australopithecines like the famous Lucy.

"Shortly" later (since about 1.75 mio y.a.) homo erectus emerged.
With a bigger brain, taller, less size differences between male and female.
And shorter gut, smaller teeth.
They were less adapted to climbing - this could indicate they already had
fire to scare away predators at night. The first fire usage is disputed.
There are very interesting articles from a Dr.Wrangham "The raw and the
stolen" who explains the increased nutritional density we expect of homo
erectus (infered from the gut and teeth, maybe the brain) and some other
facts with the usage of fire and the availability of USOs.
(USOs are underground storage organs which can be dig out like yams -
tubers)

From homo erectus emerged all later hominids and homo sapiens.
Neanderthals split off some 600,000 y a and entered the cold north (europe)
where they experienced warm and cold phases. And died out some 30,000 y a.

The first real homo sapiens findings are in africa some 100,000 y a and may
be a split off from late forms of homo erectus or intermediates but not from
neanderthals. Now we have anatomical modern humans (AMH). Real lookalikes.

After 40,000 y a  (in the last phase of maximum glaciation) some AMH
enterd into the cold north zones, where some of them may have lasted up to
the current warm phase. Only after that we find developements like
bow/arrows better clothing, fishhooks, fishnets  and better stone tools.
Jared Diamond postulates that AMHs only after 40,000 bc were not   only
lookalikes but also think-alikes. It was the time of a "great leap forward".

It's shure that they mixed later with other AMH, which dropped in from
southern warm areas after 10,000 bc and later.
That's called the neolithic revolutions because they brought the
agricultural technology with them (grains, legumes, lifestock,
house-building, food-storage...).

In all that evolution the only time when humans or humanoids in our line of
anchestry had access to fat wild game is when they entered north, of course.
This is only after 40,000 ya.
If the "chinese" theory is right, which postulates many simultaneous
developements of AMHs out of erectines in different parts of the world,
then the time of megafauna exposure would be much longer.
(Also erectines spread over much of the world, 1 mio years ago and
experienced glacials in northern areas. But the first anatomical modern
human findings are only in africa and only much later (40,000 ya) in other
regions).

Anybody some additions or objections?

regards

Amadeus S.