Re: [asa] Of motes and beams

On 7/18/06, Alexanian, Moorad <alexanian@uncw.edu> wrote:
>
> The example is that humans have built-in abilities that can be used in
> new situations without meaning that they have evolved. It is a question of
> time scales. If a system can readjust itself to new circumstances in short
> periods of time, that cannot be called evolution.
>

Can you explain why you say this? It's evolution if the principal mechanism
of adjustment is mutation + natural selection. The timescale is irrelevant.
You can make evolution happen in a computer simulation that runs in a
fraction of a second, and it's still an evolutionary process. Admittedly
the valuable applications of genetic algorithms are few and far between, but
they do exist. I agree it doesn't _prove_ humans have evolved, but that
wasn't what I was trying to prove - all I was saying is that you can't per
se call evolution a bad thing, or say it has a "bad track record". If it
didn't go on in your immune system you'd be dead very quickly, as
tragically, victims of AIDS find out.

For what it's worth, I was extremely sceptical about evolution of different
species for a long time, based on my own experience with genetic algorithms,
and how difficult it is to get them to solve any worthwhile problems.
However, I'm reading a very helpful book at the moment that goes a long way
towards answering the questions I had, namely "Darwin in the Genome" by Lynn
Caporale. It is also refreshing that Caporale doesn't use her science as an
excuse to bash religion (and explicitly says so). One of the key
limitations of genetic algorithms appears to be that mutation is completely
random (ie equally likely to strike at any point). However, a simple
observation from Caporale's book (that the four bases A,C,G and T are
slightly different), leads to the fact that mutation isn't equally likely
everywhere - in fact there are localised hot spots where lots of mutations
occur and areas where very few mutations occur. This is precisely what is
going on in antibody evolution - the bit that binds on to the antigen
mutates rapidly, and the fixed bit of the antibody (that sends some sort of
signal for the rest of the sytem to act, as I recall) doesn't mutate. But
the mutation process happens exactly as it does over generations - by
inexact copying when a DNA molecule replicates itself. There is essentially
no difference here between this type of replication, and when DNA replicates
to produce sperm or egg cells, in that inexact copying gives rise to
mutations.

Iain

Of course, the time scale of readjustment is of the order of the lifetime of
> the system.
>
>
>
> Moorad
>
>
> ------------------------------
>
> *From:* Iain Strachan [mailto:igd.strachan@gmail.com]
> *Sent:* Tuesday, July 18, 2006 3:44 AM
> *To:* Alexanian, Moorad
> *Cc:* Vernon Jenkins; George Murphy; Don Nield; asa@calvin.edu
>
> *Subject:* Re: [asa] Of motes and beams
>
>
>
>
>
> On 7/18/06, *Alexanian, Moorad* <alexanian@uncw.edu> wrote:
>
> I am not sure I understand. When a human encounters a new mathematical
> problem and is able to develop a solution to it with the prior information
> he/she has about mathematics, can we say that the individual evolved or just
> that the human brain has the ability to "figure out" new situations with
> already existing elements?
>
>
>
> I wouldn't say that the solving of a mathematical problem, a sequence of
> logical steps based on some informed guesses, bears any resemblance to the
> evolutionary processes by which the immune system works. Unless you solve
> mathematical problems as in a cartoon I once saw depicting Einstein's
> blackboard, which had three lines on it: E = ma^2 (crossed out) E = mb^2
> (crossed out) E = mc^2 (tick). No-one solves maths problems like that so
> to bring it up is an irrelevancy.
>
> Iain
>

-- 
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