Piotr to Mark wrote
> The methodology used in establishing the Mitochondrial Eve
> Hypothesis has been criticised by geneticists. Though beguiling
> and often cited in the popular media, it's just a hypothesis, and
not
> a very solid one at that. A bottleneck about 75000 years ago?
> Modern humans had spread all over Africa and much of Eurasia by
> that time, and were just about to make their first inroads into
> Australia. It was, on the whole, a very successful species, and the
> people of 75 ky BP were pretty well like us, even if their
> technologies were less advanced. Their behaviour and subsistence
> methods were flexible; their survival strategies worked in the
tropics
> as well as along the edge of the northern ice cap. They had a
> variety of flint implements, hunting weapons and clothes, knew how
> to make a shelter if a natural one wasn't available, or how to
light
a
> fire... Why should a volcano eruption on whatever imaginable scale
> have significantly reduced the population of such a widely
> distributed INTELLIGENT species without wiping most of the other
> life forms on Earth?
It would appear that until the Lake Toba explosion Homo sapiens
sapiens had been confined to Africa by the equally successful Homo
sapiens neanderthalensis stretching from the Atlantic to the Chinese
border. Similar archaic Homo s. have been found in Java and
Northern China. It appears that Homo errectus was going the same
way that other far flung populations of successful species and
evolving into regional sub-species and eventually (if allowed to
continue) possibly 4-5 different Homo. species altogether. Homo
sapiens sapiens was the African variety. Homo sapiens sapiens finds
have been found circa 90,000 BCE in Palestine, but everywhere they
were replaced in these locations by the equally successful (and more
cold adapted) Neanderthals.
The Lake Toba explosion (73,000 BCE) was important because it
produced
a sudden, global cooling of the environment found world wide.
Increasing aridity caused a retreat of Hominids out of the Sahara,
back to refuges on the Atlantic coast and south and east into the
higher rainfall areas. Homo sapiens sapiens numbers probably fell as
a result. Sea levels also fell, and an alternative route out of
Africa was opened up than through Palestine, namely across the Afar
triangle into Yemen.
It would appear that a littorial culture managed to make the escape
across to the East, following the same route taken out of Africa by
the first Homo errectus nearly 1.8-1.5 million years earlier. The
archaeology of that part of the world is very poorly known at
present,
but there are finds of Homo sapiens sapiens in northern Australia and
southern China that have been accurately dated to 63,000 years ago.
Being a littorial culture too means that their route taken means
their
finds are currently below sea level.
> Some people apparently cannot live without some "scientific"
> version of Noah's story.
So Piotr rather than a Noah story, it seems that it was an
"anti-Noah", fall in sea levels and a fall in Human populations,
followed thereafter by a sidden increase in Homo sapiens numbers as
we
collonised new environments in South East Asia, East Asia and
Australia. The littoral (coastline) nature of the culture explains
the interest in boat and raft building, necessary for the sea voyage
to Australia. It also explains how Homo sapiens sapiens and Homo
errectus in Java could co-exist until 29,000 BCE (as they exploited
different food sources). It is strange how just as the flood story
is
so widespread, of equal provenance is the tales of other species of
"humanoids" (Giants, fairies, trolls, in Europe, Masalai, Ginagabee
in
the Papua New Guineans and Aboriginals people. China also has its
own
crop). Only Africa and the Americas seem to have cultures deprived
of
other humanoids (which are the areas where other humanoids were
absent!)
As to whether Lake Toba produced the genetic bottleneck or not it is
interesting that there appears to have been some kind of trade off.
Either a very small number of humans (at 130,000 years BCE) or a
larger number bottleneck more recently (eg. 73,000 years BCE).
It would appear that only with a subsequent escape from Africa, via
Palestine some 40,000 years ago by the specialist big game hunters of
the Aurignacian culture (Glen's Dene Caucasians) that direct
competition occurred between the more mobile Homo sapiens Big Game
hunters and the more say at home Neanderthals. The Big game
specialisation seems to have carried Homo Sapiens across the Eurasian
steppes to Berengia (the Alaskan land bridge) by about 35,000 BCE.
Only in the western half of this range was there direct contact with
Homo sapiens neanderthalensis.
Glen and I both feel that the next mjor break out of Africa was with
the "broad spectrum hunter-gatherer revolution" using microliths,
bows
and arrows, and, once they got into the moddle east, accompanied by
the domestication of the dog, some 12,000 BCE. This would appear to
be associated with the spread of Nostratic languages.
Linguistics, genetics and archaeology definitely do seem to be coming
together into a single study of the science of human origins.
Regards
John