Re: Evolution, the central dogma and mutation (was Re: Extropianism & Theology)

From: ASpidle@aol.com
Date: Sat Feb 27 1999 - 20:37:30 MST


In a message dated 2/27/99 9:32:37 PM, Tim wrote:
<<
Trouble is that Darwin, Huxley, and Crick et al. never said that force did
not equal mass times acceleration. They did say that man and all other life
evolved entirely without design from natural selection upon random
mutation*. Introducing physics is a red herring being fed to a straw man.

F=MA operates when a vase is being broken on the floor just as accurately as
when the space shuttle is docking with MIR. To call it an "organizing"
principle is just plain wrong.

* not exactly true as Darwin did entertain the possibility that what we know
now as the "central dogma" might be wrong. Essentially the central dogma
says that the environment cannot guide mutation - Darwin did not rule this
out and so was initially a moderate Lamarckian.
>>

Thanks Tim, for the "Central Dogma" terminology. I know you scientists hate
arguing with non scientists about science (my son certainly does).

However, I just used a couple of physical laws as metaphors for the type of
laws that,I believe, will be found to govern emergant properties in complex
systems as we continue to lokk for them and test them. Saying that the laws
of nature (as scientists use them) are not organizing principals is, I
believe, plain wrong.

What do you know about fitness landscapes and adaptive walks? My limited,
layman's understanding is that if you lay out a 2 dimensional plain wherein
each point is a particular critter's gene sequence, and the entire plain
represents all the possible sequences in that species and then asign a
relative fitness number to each sequence (from 0 to 1) that would be a fitness
landscape.

For improving adaptation to work, the surviving offspring would have to have
enough different alleles of the correct kind that would result in higher
relative fitness for them.

Now if mutation is totally random, the landscape would be totally chaotic and
there would be no way to tell if the adjacent sequence would lead anywhere,
much less to higher fitness.

A correlated landscape, with smooth Mt. Fugi like slopes would only have two
directions (up and down) and there would thus be a situation where half the
offspring would be more fit, and half the offspring would be less fit.
Natural Selection could thus choose between the limited number of options
presented to it.

In this model (which seems intuitively more likely than the random, chaotic
model) the correlated fitness landscape represents the natural, built in order
that emerges in many complex systems, the physical laws of emergent
properties, if you will.

However, much work needs to be done to test this hypothesis.

None-the-less, it should at least show you believers in the Central Dogma
(which seems much like an Atheist Religion to me, complete with blasphemers to
be wary of) that this idea that we are lucky garbage that just happened to be
randomly selected might just be wrong.

The belief that we are the inevitable result of he laws of this universe and
(so far) the apothesis of it's creation is at least as likely, and I think
much more so.

One mans blasphemer is another mans sound meme set.

Adrian



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