Guy Hoelzer  wrote:

> in article bl1v21$1fov$1{at}darwin.ediacara.org, Anon. at bob.ohara{at}helsinki.fi
> wrote on 9/26/03 11:03 AM:
> 
> >> I think that Dawkins stands apart from the rest of those you
mentioned in
> >> his insistence that selection at the level of the gene has the primary
> >> control of biological evolution.
> > 
> > I thought Dawkins had clarified his position, and separated out the
> > levels at which selection acts (=vehicles), and the levels at
> > heritability acts (=replicators), so that now his argument is that
> > "replication at the level of the gene has the primary control of
> > biological evolution".
> 
> I must admit that I don't follow Dawkins' constant bouts of clarification
> and IMHO skillful obfuscation in response to criticisms, although I am aware
> that he has made the argument you described.  IMHO, this position nullifies
> the criticisms to which he was responding, but creates even bigger problems
> in the process.  Reproduction (or replication) is always error prone
> (mutation) to different degrees, and it is an essential element of the
> process of natural selection as we understand it in biology.  Sexual
> reproduction results in low fidelity reproduction, but greatly increases
> heritable variation, another essential element of the process of natural
> selection.  The net effect of sex on natural selection at the level of the
> individual, therefore, depends on the relative loss of potential due to
> decreased fidelity and the relative gain in potential due to the increase in
> heritable variation (specifically the extent of heritable variation for
> fitness).
> 
> At the level of the gene fidelity is very high, but mitosis and meiosis
> virtually eliminate heritable variation for fitness among gene copies.
> 
> IMHO, Dawkins presents the appearance of a logical argument, but his
> intensely subjective interpretation of the basic ideas is logically flawed.
> The terms he chooses to use, replicators and vehicles, are rhetorically
> loaded and help him to guide the focus of his followers to the gene as the
> foundation of the process and the individual as some sort of auxiliary
> construction of the genes when he provides no real basis for this sort of
> asymmetry.  On what basis does he think that replication can occur at one
> level (genes) while selection can occur at another (the individual)?
> 
> > This clarification took place after he wrote Selfish Gene (and was made
> > by him and, I think, Hull, in the early 80s), which shows the problems
> > of reading old literature.
> 
> I agree that this problem exists, and that I sometimes exhibit it when I
> criticize Dawkins.  I am also prone, like most of us, to the undue
> persuasiveness that Dawkins can wield, given his extraordinarily elegant
> writing.  However, unless I am missing something, I think this
> "clarification" leaves Dawkins in an untenable position.
> 
You are better off, I think, if you use Hull alone, and leave Dawkins to
others to explicate. Hull's article in the Stanford Encyclopedia of
Philosophy (online somewhere - I can't find it now, but Google) on
"replicators" is the best spot to begin.

Hull rejected "vehicles" in favour of a more neutral term -
"interactors". This is best exemplified in the short title of one of his
papers: genealogical actors [replicators] in ecological roles
[interactors].

Hull, David L. 1987. Genealogical actors in ecological roles. Biology
and Philosophy 2:168-184.

[This relies to an extent on the prior work of Ghiselin, whose 1974 was
perhaps more strictly stated than Dawkins, but longer and harder to sell
to philosophy students and the general public. Ghiselin pushed an
*economic* notion of evolution (one that bears close examination) - what
suceeds is what trades better on the share market of life, so to speak.

Ghiselin, Michael T. 1974. The economy of nature and the evolution of
sex. Berkeley: University of California Press.]

My own problem is that it seems to me that replication is not required
either (although it obviously occurs in the vast bulk of modern biology
with nucleotides); the more generic concept is "reproduction". You need
not-quite-perfect reproducers (Wm Wimsatt's term) with interactive
differential rates of resource acquisition, for evolution to occur.

This, of course, allows for multiple layers of selection - reproducers
can be at a number of "levels" from individual strands of nucleotides
even in exons through to behavioural patterns and niche constructed
resources, and the "systems" at each level can evolve so long as they
reproduce and differentially interact. To paraphrase Shaw, we have
agreed on the nature of the transaction, now we are haggling over the
price.

It is worth noting, however, that Dawkins himself did allow for multiple
loci of selection. The very discussion of "meme" is evidence of that,
and it is this that set off Hull's attempt to develop a generalised
substrate-neutral account of evolution. Memes are not genes, nor are
they genetically-biassed (in Dawkins' original discussion). He therefore
did *not* restrict selection to genes.

What he did was this, I think: he generalised form the typical mode of
reproduction in animals to an account of a class of entities -
replicators. He then interpreted *all* evolution as replication-based,
and so restricted the typical mode to the *only legitimate* mode of
evolution. Then he went looking for analogues in other evolutionary
domains. There can be no doubt that replication does occur. The question
is whether it is both sufficient (arguably, yes) and necessary (IMO
unarguably, no).

-- 
John Wilkins wilkins.id.au
For long you live and high you fly, 
and smiles you'll give and tears you'll cry
and all you touch and all you see is all your life will ever be
---
þ RIMEGate(tm)/RGXPost V1.14 at BBSWORLD * Info{at}bbsworld.com

---
 * RIMEGate(tm)V10.2áÿ* RelayNet(tm) NNTP Gateway * MoonDog BBS
 * RgateImp.MoonDog.BBS at 9/27/03 6:03:31 AM