Received: by alpheratz.cpm.aca.mmu.ac.uk id PAA19989 (8.6.9/5.3[ref email@example.com] for cpm.aca.mmu.ac.uk from firstname.lastname@example.org); Mon, 30 Jul 2001 15:50:23 +0100 Message-ID: <2D1C159B783DD211808A006008062D3101745FD2@inchna.stir.ac.uk> From: Vincent Campbell <email@example.com> To: "'firstname.lastname@example.org'" <email@example.com> Subject: RE: Logic Date: Mon, 30 Jul 2001 12:38:13 +0100 X-Mailer: Internet Mail Service (5.5.2650.21) Content-Type: text/plain; charset="iso-8859-1" X-Filter-Info: UoS MailScan 0.1 [D 1] Sender: firstname.lastname@example.org Precedence: bulk Reply-To: email@example.com
>> I'm sorry, this is pants. Did our ancestors make the days hots?
>> Evolution doesn't need 'a kind of non material, species memory',
>> words a macguffin to make it work. All you need is a process
>>is replication, variation and selection.
<In other words, a macguffin?>
A macguffin is a a piece of artifice needed to make something work.
There's nothing like that about the processes of replication, variation or
selection. Replication happens because of chemistry. Variation happens
because that replication system isn't perfect, and selection happens because
the context in which both replication and variation occur varies. That's
not to say we necessarily understand in exact detail as yet how these
processes work, but there's little doubt that the notion of genes, and the
discovery of DNA, did provide the theory of natural selection with a
mechanism, and yes IMHO mechanism is an appropriate term to use, as long as
it's usage here is properly understood.
<You can't trust a theory that invokes the name of someone who
> rejected its central tenet. >
Yes, you can. Einstein's theories predicted black holes, but he
explicitly rejected them as impossible. Black holes are now not only
possible but probably widespread throughout the universe, not east at the
heart of spiral galaxies like our own.
<Darwin was certainly aware of the "germ-plasm"theory.
> He dismissed it on the basis of the absence of monsters in nature.
> If phenotypic characteristics could be individually molded on the basis of
> units of germ-plasm, then alterations in these units should produce
> grotesque changes in outer form. If the "germ" for ears mutated in such a
> way as to increase their size by three-fold, the world might soon witness
> the onset of a race of Mickey Mouses. Yet this doesn't happen. Clearly,
> it's because the body's form is governed holistically. This is why
> evolution is driven according to the sensible behavior of the organism
> rather than the blind workings of its macromolecules. The atomistic model
> of inheritance is unsuitable for evolution. Aristotle, Goethe, Whitehead,
> and yes, even Bergson (despite his vitalism), tell us far more about life
> than Crick and Watson ever could.>
Just visit rotten.com, if it's still there, for some of the
remarkable quirks of nature that are born into this world, but usually do
not survive very long before dying. This simply isn't true, major mutations
do occur in individuals of all species, but rarely survive to breed, unless
that mutation confers some survival advantage. There are numerous species
with, to human eyes, highly exaggerated physical characteristics, which
persist because they are adaptive within that organisms environmental nice.
<Blame the wee folks for all this mischief. What we're up against
> "homunculi" meme. We've never been able to drop the idea that outer form
> a scaled-up version of inner form. Just as Newton updated Plato's Forms
> into "laws of physics," Weismann refashioned the homunculus as a set of
> (genetic) instructions. Mechanistic evolution made a lot more sense when
> speciation was given plenty of time to unfold in simple, discrete steps.
> Yet we know, based on jumps in the fossil record, that evolution occurs in
> brief bursts punctuated with great gulfs of calm. Mechanistic ontogeny
> a lot more sense when the body contained vast numbers of genes and
> But the recent revelation that the genome is one-third smaller than
> previously imagined did nothing to call into question the reduction of
> morphology to genetics. The power of the meme against all logic ensures
> that the genetic model, both evolutionary and developmental, remains
Punctuated equilibrium versus gradualism. Jumps in the fossil
record are difficult to genuinely assess given the extreme variability of
rates of fossilisation of different species. Remember, no-one had found a
coelacanth fossil younger than about 75 million years old, until one was
caught in fisherman's nets off the coast of Africa before WWII. Genuine
fits and starts in the fossil record appear to be largely due to manjor
environmental changes anyway.
That recent assertion that the number of active genes is far
smaller, that got lots of publicity, has subsequently been widely challenged
as a very bottom end guesstimate based on the skeletal results rather
prematurely announced by the two bodies competing to complete the sequence
first. As has been discussed on the list, it's the complexity of
interactions that is important not the basic number anyway.
<It works, not at the level of individuals, but at the level of
> form of the species evolves. As to whether this collective form is
> reducible to DNA, we don't know.>
Again, it works at the level of the genes. Go read some Dawkins.
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