Received: by alpheratz.cpm.aca.mmu.ac.uk id KAA10395 (8.6.9/5.3[ref pg@gmsl.co.uk] for cpm.aca.mmu.ac.uk from fmb-majordomo@mmu.ac.uk); Mon, 12 Feb 2001 10:56:27 GMT Message-ID: <2D1C159B783DD211808A006008062D3101745C58@inchna.stir.ac.uk> From: Vincent Campbell <v.p.campbell@stir.ac.uk> To: "'memetics@mmu.ac.uk'" <memetics@mmu.ac.uk> Subject: RE: Less genes than expected Date: Mon, 12 Feb 2001 10:55:42 -0000 X-Mailer: Internet Mail Service (5.5.2650.21) Content-Type: text/plain Sender: fmb-majordomo@mmu.ac.uk Precedence: bulk Reply-To: memetics@mmu.ac.uk
In the UK, reporting said much the same, but on a TV news interview john
shulston said that the fact that there are fewere genes that thought a few
years ago doesn't change the basic notion that both nature and nuture are
important.
I don't see how having only 30,000 genes makes us suddenly predominantly
more environmentally determined than genetically. After all this may be
only double that of a nematode worm or whatever, but given the literal
massive differences between us and worms, not to mention the emergent
properties of humans (e.g. consciousness or the illusion of consciousness of
you prefer), then that doubling is obviously extremely important.
Time for a bad analogy. Look at the massive changes in capabilities of home
games consoles as they went from 8bit to 16bit, to 32bit, and now to 128bit
hardware. I suspect that increases in the number of genes is very
superficially akin to this kind of development.
Another, not quite as bad analogy, would be in levels of communication- in a
dyadic piece of communication there is only one relationship, but the more
people you add the more possible relationships within the group there are.
Double the number of genes may mean many thousand (million?) more effects of
the combinations and joint effects of genes than is possible than with
15,000.
Vincent
> ----------
> From: Zylogy@aol.com
> Reply To: memetics@mmu.ac.uk
> Sent: Sunday, February 11, 2001 10:37 pm
> To: memetics@mmu.ac.uk
> Cc: Zylogy@aol.com
> Subject: Re: Less genes than expected
>
> It doesn't really matter that vertebrate genomes have "fewer" "fixed"
> genetic
> sequences than one might expect on the basis of average size of a gene
> versus
> the overall size of the genome carrying them. Because of variable
> editorial
> capabilities on transcription RNA, the "true" number of final protein
> products is vastly greater. Many people are under the impression that the
> genome, like the lexicon, is simply some vast repository of fossil forms.
> Sure, they allow for duplication and mutational modification leading to
> variants of the "same" gene, but that's about it. In reality, though, the
> genome itself is in constant, if glacially slow, flux. Introns and exons
> shuffling about, not to mention the repetitive intervening sequences (the
> so-called "junk" DNA) which regulate accessibility and activity of genes
> in a
> physicomechanical fashion. And because of viral incorporation and
> accidents
> of recombination, stuff is coming into the genome in unexpected places
> from
> outside. And sometimes genetic sequences are simply lost, or permanently
> inactivated.
>
> Despite all this, its a very sophisticated production system. And when
> considering its origins, one must see that it has been assembled
> throughout
> the history of life. Indeed, in eucaryotic cells many organelles show
> evidence of genetic independence at one time, but now most of the genes
> have
> either been transferred to the main nuclear genome or products of
> functional
> equivalents from there replace the originals in the organelle. Flux.
>
> In addition, many of the very complicated genes appear to have been welded
>
> together from standard, smaller parts (just as in language). One wonders
> how
> much of this still goes on.
>
> So in the end, what really is the true "number" of genes? Do we count all
> the
> variants of a single thread as separate units (such as hemoglobins) or
> one.
> Where would THAT end when many different functional types can be shown to
> have evolved from a single type (proteases, for instance)? Or do we take
> the
> easy way out and simply count the number of sequences able to be
> transcribed
> into RNA (and then protein)?
>
> I think this is still an open question, and one subject to debate.
>
> Jess Tauber
> zylogy@aol.com
>
===============================================================
This was distributed via the memetics list associated with the
Journal of Memetics - Evolutionary Models of Information Transmission
For information about the journal and the list (e.g. unsubscribing)
see: http://www.cpm.mmu.ac.uk/jom-emit
This archive was generated by hypermail 2b29 : Mon Feb 12 2001 - 10:58:40 GMT