Hi Ed,
Thank you for your feedback -- the sort of constructive criticism I was
hoping for. You say at the end that human history can't be boiled down to 7
steps. I agree. What I was trying to do was merely to describe the bones of
important innovative/economic stages and to get them into rough balance.
For brevity I'll dispense with my original and just make a few more
comments on yours:
(EW)
<<<<
One of the most interesting questions is that of when we became fully
human -- that is, when did we start thinking and behaving as we now do? The
human brain, in its current anatomical form, has existed for at least
100,000 years, and probably much longer, but it would seem that it has only
been used as we use it now for part of that time. Something happened about
40,000 to 60,000 years ago that made people use abstract concepts (e.g.
past, present, future, the infinite, the afterlife) and symbols (complex
language, drawings, paintings, decorative patterns, perhaps pictographic
writing, numbers). Before that, people had not done these things even
though it is thought that the brain had a capacity to do them. Ian
Tattersall of the American Museum of Natural History deals with this matter
in the current issue of Scientific American. It is also dealt with in a
passage in "The Ingenuity Gap", in which Thomas Homer-Dixon refers to
somebody who makes the point that something rather profound happened to
human cognition some 60,000 years ago. The question this seems to pose is
whether whatever happened was another step in biological evolution or
whether it was an example of what Tattersall calls "exaptation", the usage
of an adaptation that had been there for a long time but was not used until
some sequence of events required it to be used.
>>>>
This is not quite the case. An adaptation doesn't stick for very long
unless it has an immediate use. But, in time, the adaptation might develop
much further and become more sophisticated as its use changes -- even
radically. (E.g. feathers originally developing as heat insulators and then
into useful aids to flying.)
(EW)
>>>>
However it came about, it
was probably after it happened that people were able to adapt to a variety
of environments, invent things like the atlatl, the boomerang, the harpoon,
the domesticated dog, the boat and a variety of other things that made life
progressively easier.
>>>>
Referring to the whole of your paragraph, yes, I'm aware of Tattersall's
views of "exaptation". But this is only one of several competing theories
as to how abstract thinking started by means of preliminary adaptions and
behaviours. Another currently popular one is that the advanced faculties of
the brain arose from courtship behaviour. The more subtleties that a male
portrayed when courting a female, the more likely he was to be chosen. This
type of sexual-based adaptation (rather like the role of curly horns of
some goat or sheep when they're courting) has a "runaway" ability -- that
is, that it can evolve very quickly indeed over a few generations only even
though it does not have any direct survival benefits. In the case of goats,
the curly horns have not become useful for survival purposes and the poor
males are lumbered with them ('cos the females still like them) but, so say
biologists like Geoffrey Miller (see "The Mating Mind", Vintage, 2001),
man's courtship behaviour had much more important effects in due course.
Yet another important claimant for the origins of man's conceptaul
abilities is that it is an "elongated" byproduct of normal human gossip
(see "Grooming, Gossip and the Human Language", Faber & Faber, 1996)
(EW)
<<<<
Another issue focuses on whether we are a distinct or hybrid species.
Though some may consider the matter settled, there are still conflicting
points of view on the matter. One that seems to holding the field right now
is that we are all descended from a single female who lived in Africa some
200,000 years ago. This is based on research on mitochondrial DNA. A
competing point of view, one which is losing ground, is that, over the past
five hundred or so millennia, there were multiple migrations of essentially
different human species out of Africa, and that these mixed and interbred in
various parts of the world to produce fully modern humans. The idea here is
that we are the product of an enormous, widespread, and prolonged mixing of
gene pools, including those of poor old Neanderthal Man who was not
displaced but continues to live within us.
>>>>
As you say, the latter hybrid theory is losing ground. I understand that
the DNA differences between Homo Neanderthalensis man and Homo Sapiens are
too great. The separation occurred a long time previously.
<<<<
You say that people migrated from Asia to North America between 22,000 and
13,000 years ago, so you must be implying widespread glaciation and the
existence of the Beringian land bridge at about that time. I have no real
quarrel with that. That is about when Beringia existed as a home to
migrating animal species and the hunting societies that followed them in a
general eastward drift. However, your point about the sudden ten degree
drop in temperature some 13,000 years ago raised my eyebrows. I know that
temperatures fluctuated considerably glaciation receded, but ten degrees
seems rather excessive. I would like to know where you got that.
>>>>
I can't give you references for this. I got this info from a BBC radio 4
programme and I missed the names of the discussants. The gist of it is that
for quite a long time climatologists had known of some sort of temperature
drop at that time but that, recently, it has been (a) fixed very precisely
at 10,080BC (b) fixed very precisely as a fall of 10 degrees C (c) lasted
for 1,000 years, and (d) it occurred very rapidly (but I didn't catch what
they meant by that). I'm anxious to find out more. This period was probably
a catalyst for the beginning of agriculture because it might have been the
final blow in removing many animal habitats on which hunter-man depended.
(EW)
<<<<
As you probably know, the concept of migration over the Beringian land
bridge as being the only way that early people got to the Americas has come
under fire recently. Kennewick man has raised a number of questions that
have made proponents of the land bridge and some North American Native
people rather uncomfortable. Some authorities now hold that South America
was inhabited before North America, and that North America may have been
inhabited in the southeast before it was inhabited in the northwest. One
theory, based on the similarity of tools between Solutrean Europe (18,000 to
about 15,000 BP) and those found along the eastern seaboard of the US and
even Clovis tools suggests that people may actually have migrated to North
America along the edge of the ice-sheet that covered the north Atlantic
during the last glacial period. Much of this is written up in a fascinating
book called "Bones" by Elaine Dewar. Dewar is a journalist, not a
scientist, but in her research she interviewed many scientists in both North
and South America. To my knowledge, none of them have sued her for
misrepresentation yet.
>>>>
I'm not terribly au fait with this although I've come across it vaguely. It
occurs to me that what would support this is that the Incas were just on
the verge of producing brass. This needed quite a long cultural
"apprenticeship" which was unlikely if man had come down more recently from
the north. (And they would have been "travelling light" -- i.e. there's no
evidence of settled cities with a variety of necessary skills therein which
would have been required for the development of a brass refining culture.)
<<<<
I could go on and argue that the scientific method pre-existed the
Enlightment, but I'll stop here. My main point, perhaps the only one worth
making, is that human history is far more complex than something that can be
boiled down into seven points, with or without morning tea.
>>>>
Well, there were any number of most amazing technological devices (e.g.
steam engines, flame-throwers, telescopes etc) among the early Greeks,
Romans, and also in Persia, India and China, all long before the
Enlightenment period in western culture, but they remained as novelties and
were never developed further, either as economic goods or as forerunners of
scientific experimentation. But if you know of such, I would be delighted
to have knowledge of them.
Once again, during this morning's pot of tea (I am now on my last pot of
the day -- my better-half is upstairs with her madrigal group lustily
singing Lasso), I wanted to mention what I thought were the significant
economic stages.
Keith
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�Writers used to write because they had something to say; now they write in
order to discover if they have something to say.� John D. Barrow
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Keith Hudson, Bath, England; e-mail: [EMAIL PROTECTED]
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