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Thanks, Pete, but I'm not sure I really agree, especially with your
argument about it all depending on the slow accumulation of culture and
about it taking a long time to invent and diffuse things like fish hooks and
needles. Sorry, but I believe Homo sapiens is brighter and
faster than that.
I was a bit miffed at Keith's dismissal of Stephen Mithen whom I mentioned
in one of my earlier postings, so I decided to see where Mithen's ideas stand in
the current literature. To do so, I went down to my university library and
picked up a couple of books, one a book of readings, the other a text
book. I'll refer to the latter in what follows. It's Bjorklund, D.F.
and A.D. Pellegrini, The Origins of Human Nature, American Psychological
Society, 2002. Like Thomas Homer-Dixon, Bjorklund and Pellegrini give a
lot of credence to Mithen's concepts, most basically the concept that what
distinguishes us from other primate species is the ability to have attained
"cognitive fluidity" and thus being able to use the various modules of the brain
simultaneously. Specifically:
Mithen (1996) [proposed] that hominids evolved
powerful, domain-specific modules to deal with their natural and social
worlds, but it was not until the emergence of modern humans about 100,000
years ago that Homo sapiens were able to integrate the information-processing
abilities of these modules to produce a general-purpose intelligence. In both
cases, it appears that a domain-general mechanism is proposed as the necessary
addition for the emergence of the modem human mind.
(p.144)
This, of course, begs the question of how a
"domain general mechanism" may have emerged. Here Bjorklund and Pellegrini
note:
Domain-specific mechanisms will be favored when environments remain
relatively stable, with individuals facing recurrent problems generation after
generation. ... In contrast, domain-general mechanisms will be favored
when environments are unstable and the nature of the problems individuals face
varies over generations. Under these circumstances, flexible, decontextualized
problem-solving routines would be most adaptive .... For example, ... the
environment in which humans evolved was characterized by frequent and
noncyclic changes in climate.... This would have resulted in unpredictable
changes in habitat, requiring individuals to be able to respond to situations
unlike any their recent ancestors faced. It is exactly in such situations that
flexible, domain-general mechanisms would be favored.
(Ibid.)
One thing we do appear to agree on is that, due to some unknown
cause, the human population declined to the near extinction level at one
time. Evidence for this is the unique similarity of DNA across all human
populations. No other primate species even comes close to us in this
regard. A reference I have suggests that the near die-out would have
happened more than 70kya, before we left Africa, and that the population may
have gone as low as 2,000. Given the enormous threat faced by the human
population, what better time to get our brains in order and develop cognitively
fluid thinking! We may have had the capacity before then, but we may not
really have used it very much, or we may have used it here and there but not
consistently.
According to sources cited by Bjorklund and Pellegrini, cognitively
fluid thinking requires a long maturation process as the individual moves
from the domain-specific to the domain general. Young children do not
think that way and it is only when the brain is fully formed in late adolescence
and early adulthood that individuals become cognitively fluid. Of course,
a proportion of the population may never get there.
It would seem, from material in Bjorkland and Pelligrini, that we are
the only human species to have become full-time cognitively fluid
thinkers. To become that requires a long maturation that takes the brain,
step by step, through a process beginning at infancy and ending at
adulthood. Not even Neanderthalers with their large brains appear to
have made it, or did so to only a very limited extent, because they
matured to adulthood much more rapidly than we do.
This brings me to the giants upon whose shoulders Newton stood.
Here, I would not include the guy that invented the fish hook, the spear or the
atl-atl. Many groups of people would have done these things at different
places and times. More probably, Newton was referring to people who used
cognitive fluidity with exceptional grace and rationality, people like
Aristotle, the genius in India who invented the concept of zero, the Arabs who
brought that concept plus ancient Greek thought to Europe, and schoolmen like
Aquinas and Abelard who argued religion with special elegance.
Ed
----- Original Message -----
Sent: Tuesday, November 25, 2003 12:33
PM
Subject: Re: Slightly extended (was Re:
[Futurework] David Ricardo, Caveman (fwd)
At 09:15 25/11/2003 -0800, Pete wrote:
On Tue, 25 Nov 2003, Ed Weick
<[EMAIL PROTECTED]> wrote:
>Pete, I am an
amatuer at all of this, and you have obviously read more
>than I
have. However, what I don't understand is why, if we had
>essentially modern brains 160kya, did it take us 80,000 to 100,000
years
>to demonstrate that we had those brains. I'll have to do
more reading.
>
It's all about the rate of accumulation
of culture. Newton famously
said if he saw further than most men, it was
because he stood on
the shoulders of giants. The giants he refered to are
easy to
identify, but in fact there are a cadre of giants whose
names
are lost in prehistory, to whom we all owe a great debt for
the
life we live. It is hard to realize, but such things as
fish hooks,
needles and thread, baskets, nets, wooden huts,
and many more, were
revolutionary ideas, which had to wait
for someone bright enough to not
only conceive of them, and
persist in working on them til they were
effective enough to
attract wider adoption, but I think most importantly
to realize
that innovation was a possible option, when most of the
hardware
which persists in the archaeological record appears to have been
unchanged for _hundreds of thousands_ of years prior. The
frequency
of innovations at first must have been so low that
each innovator would
be essentially working without any living
example that it was possible,
particularly as the social unit
was probably a small band of one to two
hundred individuals
at most. It is very much a "critical mass" issue, and
was coupled
to the total population size. What ever it was that brought
our
population down to 10,000 individuals or less, may have
persisted,
limiting population growth and thus the size of the "brain
trust".
And as I also mentioned, language and lore had to develop.
You
can't have creative technological ideas if you don't have
a
cultural milieu which provides the excercise in
manipulating
concepts, something which requires a robust vocabulary.
All
these things take time, and it's hard to grasp how much time,
when
we now learn much more about many aspects of the world
before the age of
two than these people would have known at
first as adults.
-Pete
--------------------------------------------------------------------------------
Brilliantly
described. Working backwards from now, if one could plot "standard"
innovations (happening today at, say, one a month), they would probably fit on
a pretty smooth exponential curve
Keith
----- Original
Message -----
From: "pete" <[EMAIL PROTECTED]>
To:
<[EMAIL PROTECTED]>
Sent: Monday, November 24, 2003
11:56 AM
Subject: Re: Slightly extended (was Re: [Futurework] David
Ricardo, Caveman
> On Sun, 23 Nov 2003, Ed Weick
<[EMAIL PROTECTED]>
>
> >And I would take issue with you
that we are now the same as we were
> >100/200,000 years
ago. Stephen Mithen of the University of Reading, as
> >one
example, argues that until about 70K to 80K years ago, our brains
>
>were relatively compartmentalized; that is, we were a lot like cats who
> >think about mating and nothing else when mating, hunting and
nothing else
> >when hunting, socializing and nothing else when
socializing, etc. At the
> >time, our rather limited
thoughts and actions were highly genetically
> >determined.
Then something happened. The wiring that controlled all
>
>that began to fall away and we became, as Mithen puts it, "cognitively
> >fluid"; that is, we could think across all of those little
compartments
> >and use them all at the same time. The
result was an explosion in
> >creativity and also an explosion in
our capacity for mischief. Not
> >everybody agrees with
Mithen. Some argue that a "creativity gene" arose
> >some
50K to 100K years ago.
>
> Despite the substantial media
coverage given to short-chronology champions
> like Klein, and to a
lesser extent Mithen, these are not the majority
> view in paleo-anth
regarding the rise of Homo sapiens. Molecular
> evidence is persistent
in putting the start of the clock for our
> particular string of
ancestors at around 150-200kya, and archaeology
> supports this with
indications of transitional but mostly modern
> phenotypes in
northeast africa @ 160kya, and tools along the Red
> Sea shore around
125kya. The thinking is that culture is a huge
> part of what we
currently are, and the accumulation of this, in the
> form of
sophistication in language, technology, and lore, takes a
> long time
to develop. The effect is essentially exponential, rather
> like
population growth - we had the essential modern mental hardware,
>
but it took in the order of 100ky for our particular string of
ancestors
> to build up their population to the point that they were
able to
> develop and retain the necessary cultural tools to achieve
the
> material trappings of modernity. Consider that the
Neanderthals
> were in europe for perhaps 300ky with essentially the
same toolkit,
> yet were able apparently to begin absorbing the
refined tools of
> Homo sapiens as soon as they arrived on the scene.
This indicates
> I think the essential mobility of culture, and its
independence
> from creative intellectual capacity.
>
>
The strong objections to the 50kya figure also refer to the current
>
indications of human migrations. The evidence is that we were
> out of
africa by 100kya, and heading east and south, much more
> hospitable
places at that time than europe, which resisted our
> incursion until
we had developed the cultural solutions to cold
> weather living,
perhaps as much as 40 or even 50ky later. By that
> time we had
penetrated SEasia and were working our way northeast
> along the
pacific rim. If Mithen's timing were correct, all these
> people would
be deprived of his eurocentric genetic advance, which is
> clearly
not the case.
>
> Whatever happened, appears to
have happened
> >to all of us alive at that time in just a few
generations, and it would
> >seem that there weren't very many of
us. As is suggested by the unique
> >similarity of human DNA
among primate species, there may only have been
> >some 2,000 of
us, the survivors of some natural disaster barely managing
> >to
stay alive somewhere in Africa.
>
> The puzzle of our genetic
lack of diversity is not resolved, as
> it appears to have developed
while we were in africa. Apparently
> we chose not to, or were
prevented from interbreeding with the
> extant Homo lineages in
africa, and when we had developed a
> distinct gracile phenotype, we
appear to have displaced, rather
> than absorbing into each other
hominid type we encountered
> as we spread south into africa and north
into the rest of the
> world, spreading our meager but potent genetic
legacy.
>
> -Pete Vincent
>
>
> _______________________________________________
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mailing list
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_______________________________________________
Futurework
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Keith
Hudson, Bath, England, <www.evolutionary-economics.org>
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