Message-Id: <v03102802b358bcf7bd93@[194.109.13.153]>
In-Reply-To: <85256769.005AD1FD.00@m-ms01.frb.gov>
Date: Fri, 7 May 1999 20:29:56 +0200
To: memetics@mmu.ac.uk
From: Ton Maas <tonmaas@xs4all.nl>
Subject: Re: Darwin and Lamarck
Guy Lukes wrote:
>>Ton Maas wrote:
>
>>>I've said it before, but since this topic has crept up once again, I'd
>like
>>> to emphasize the fact that Gregory Bateson has been "defending" Lamarck
>>> quite elegantly for many years. His position was that Lamarck's error
>was
>>> one of logical typing: the inheritance of acquired characteristics may
>not
>>> be true on the level of the individual organism, but it is most
>certainly
>>> true on the level of the population or gene pool.
>>
>
>>Ton, could you explain this in more detail, preferably with an example.
>
>I am also interested in what Bateson means. So in the interest of
>stimulating converstion I will post my own crude interpretation in the
>hopes of stimulating a Bateson advocate to respond.
Okay, let me first try to rephrase what I was trying to get accross, and
then see how this fits in with what others - notably Guy - have stated. The
main intellectual manoeuvre Bateson has undertaken in his book "Mind &
Nature; A Necessary Unity", is to draw a formal parallel between the
process of natural evolution and the process of learning. He does, however,
emphasize at least one fundamental difference between the two: biological
evolution is different from learning in that it contains rather stringent
conserving mechanisms such as the Weissmannian barrier, preventing acquired
characteristics from entering an individual's genes, thereby slowing down
the process of adaptation considerably. [One of the reasons Lamarck came up
with his scheme and Darwin embraced it, is the simple fact that they had to
"market" their ideas in a society which was saturated with the biblical
calendar of just a few thousand years between the creation of the world and
the present day.] Learning, on the other hand, doesn't feature such
inherent limitations on adaptation, and therefore is far more prone to
"unguided" creativity (often resulting in madness). One of Bateson's
favourite statements - that one needs both Rigor and Imagination to ensure
a sensible course of development - expresses a similar concern.
One logical level up from the individual organism is the species, or rather
(when we speak of heredity), the gene pool of that species. On this level
environmental pressure is not "up against" any Weissmannian barrier, since
its effects are statistical rather than directly genetic. The main
limitation on the adaptability of a species is the amount and the location
of adaptive flexibility - or conversely, stress - in its variables. This is
where Bateson draws on Lewis Carroll's wonderful story of the
bread-and-butterfly, which has a lump of sugar for a head and thin slices
of bread and butter for wings. When the gnat tells Alice that its food is
weak tea with cream in it, she immediately sees the problem. Whether the
poor animal does or doesn't find its food is irrelevant to the outcome,
which is always the same: death - either by starvation or by dissolving.
What then is extinction? According to Bateson, this situation is formally
similar to a Double Bind: no matter which one of all possible solutions
each individual organism chooses, the outcome is invariably the same. It's
an evolutionary cul-de-sac. And the beauty of it is that you don't need to
introduce gigantic comets or meteors (Dei ex Machina) to explain it. The
dinos had chosen an evolutionary path that seemed to pay off for a long
time, but in the end they got trapped between two impossible choices,
either grow smaller and be defeated by the competition, or grow larger
until they literally collapsed under their own weight. You can't maximize
certain variables without "eating up" the flexibility of the total system.
Indeed, you can go quite far - as blue whales are still proving as of today
- but you need pretty sophisticated tricks (such as maintaining a one pound
thighbone swimming around in a layer of fat just under your former hip) to
keep the scales in balance.
So, wheras the influence of environmental pressure on the population is not
without limits (although these are gradual rather than strictly defined),
its effects _are_ "instantaneous", meaning that it doesn't take dozens or
hundreds of generations before they start showing up in the real world. In
Batesons words:
"Evolution looks _as if_ it were Lamarckian".
How 'bout that for a first response?
Regards,
Ton
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