Re: ecological complexity

Mario Vaneechoutte (Mario.Vaneechoutte@RUG.AC.BE)
Wed, 2 Sep 1998 15:52:11 +0200


Alexei Sharov wrote:
Mario Vaneechoutte wrote:

> >Could you explain your agreement in more detail? To be honest, as a biologist
I
> >agree with Dawkins, Gould, and most other biologists that natural selection
is
> >nothing more than a blind seive, without teleology, and the above sounds like
> >blasphemy or scientific nonsense! And what do you mean by free will? It
> does not
> >really exist.I would like to understand what good reasons you have to agree
on
> >the opposite of the current paradigm.
>
> Mario, you can find the discussion of this in Jesper Hoffmeyer's
> book "Signs of Meaning in the Universe" 1996.

I have read Emmeche & Hoffmeyer 1991 (which is online: Emmeche, C., & J.
Hoffmeyer.
1991. From language to nature. The semiotic metaphor in biology. Semiotica 84:
1-42.http://alf.nob.dk/~emmeche/cePubl/91a.frolan.htm
) and find it most interesting. I dislike books, since it always takes months
(and
money!) before I can get them. Don't you have an online summary of this. I'd
love to
read it.

> In short, there is no "blind seive". Any seive is an instrument
> and somebody makes use of it, otherwise it is not a seive. What
> we call "natural selection" (a very confusing term!) is a mechanism
> by which the population probes the environment and selects which
> organisms should reproduce and which should not.

Well, this puts thing on their heads! The population does not probe anything,
I'd
say.When you have variation on a theme, then none, one, some or all of the
variations will be able to exist in a certain environment (which contains the
other
variations as well of course). Whether we call this a seive or not, it is what
selection is about in general (natural or not). I find it truly confusing and
even
erroneous to say that there is a population which probes the environment and
which
selects. Selection is something which is the result of having certain
environmental
conditions and variations on a theme with possibly different 'viability' in that
environment.
There is no 'which SHOULD reproduce or not'. Those that could reproduce are
still
here, that's all.

> Unfortunately,
> many biologists like Gould can think only of individual adaptations
> and dismiss ideas of adaptations at higher hierarchical levels
> (e.g., populations). In order to make use of "natural selection", a
> population must "remember" which organisms performed best; thus, it
> needs inheritance which is population's memory. Also, it needs some
> sort of a search engine which generates variability. This engine
> includes mutations, recombinations. Epigenetic constraints are used
> to prevent blind repeating of previous mistakes. All these mechanisms
> are adaptations at the population level which were selected at a
> higher level of "natural selection". There is a hierarchy of
> "natural selections" that correspond to different time scales.
> Michael Conrad wrote a book "Adaptability" in which he explains this
> hierarchy of natural selections.

Possible, all kind of books have been written. But this is not the standard view
of
biology and there are good reasons. (See Evolution by M. Ridley as cited in the
language article (see below): Group selection can occur, but is limited and
mostly
to weak to overwhelm natural selection. I touched this problem in the article on
language as cited in the signature below, and give an example of where group
selection is possible. Gould is probably the last one to blame for being
adaptationist, since others like Dawkins blame him - among other things - to be
too
group selectionist and to be not enough adaptationist.

>
>
> However, it is impossible to consider natural selection at all
> infinite levels. Thus, for practical purposes, we cut it at some
> level and call everything that is above "physics". For example, we
> can consider selection of individuals without thinking of adaptations
> at the population level. This is like an 8-digit calculator that cuts
> off extra information. But people like Gould think that the 8-th digit
> is the last one and there is nothing beyond.

I would be the first to say that natural selection has limited applicability.
E.g.
I' d say that the origin of life cannot be explained by NS, while the standard
view
is that of the RNA-world whereby 'self replicating' molecules undergo natural
selection, because of differential reproduction rate (which by the way is not
the
same as differential survival rate: survival is unimportant in biology,
reproduction
is). Also selection comes only after variation has been 'created', through
mutation
and recombination (through symbiosis, sexual (bilinear) recombination or
cultural
(multilinear) recombination). A lot of evolution can be explained through the
absence of selective constraints, e.g. when a new building plan comes into being
like was the case for animal multicellularity: at that moment any variation goes
because there is nothing like it and the niche is empty. This empty niche,
always
open for more complex organisms may explain why evolution almost inevitably
leads to
more complexity: there is always room for more complex organisation. Evolution
is
open ended towards more complexity, (more complex organisms initially have no
competitors).

>
>
> The term "freedom" has a lot of connotation. But for scientific
> purposes we can view freedom as making use of variability. Obviously,
> it is outside of physics because physics does not study usefulness.
> But biology studies adaptation which is the same as usefulness. Thus,
> freedom can be studied within biological sciences. The most simple
> example of freedom is mutation.

I'd hesitate to call mutation freedom, since it is deterministic, but still then
this has a different connotation than free will.

>
>
> >Why should we need QM all of a sudden to explain consciousness, while we
could
> > do
> >without to explain the rest of evolution? This is a bit like pretending
> that, to
> >explain human existence, you need some kind of deus ex machina solution.
>
> Here I agree with you completely! There is no need for QM to explain
> variability. In most cases we simply don't need to explain variability,
> we simply postulate it (the same 8-digit calculator!). I don't mean to
> forbid using QM for explaining evolution or free will. I just say that
> we can understand a lot about evolution and free will even without QM.
> May be eventually QM or some other physical theory will be able to add
> some details, but now we are not talking about details.
>
> -Alexei
> -------------------------------------------------
> Alexei Sharov Research Scientist

Best regards

--
Mario Vaneechoutte
Department Clinical Chemistry, Microbiology & Immunology
University Hospital
De Pintelaan 185
9000 GENT
Belgium
Phone:   +32 9 240 36 92
Fax:   +32 9 240 36 59
E-mail: Mario.Vaneechoutte@rug.ac.be

J. Memetics - Evolutionary Models of Information Transmission: http://jom-emit.cfpm.org/

The memetic origin of language: humans as musical primates http://jom-emit.cfpm.org/1998/vol2/vaneechoutte_m&skoyles_jr.html