SJ Gould on genome

Charles Brown CharlesB at CNCL.ci.detroit.mi.us
Tue Feb 20 08:48:56 PST 2001


Peter,

Doesn't the very terminology genotype/phenotype imply cognizance in the theory that some environmental causes intervene after the formation of the zygote in conception ?

Peter said in his post: "Finally, I think Gould is pretty much right in spirit, but makes a couple of logical mistakes in setting forth his argument. I.e. I think we pretty much know that 'information' resides in the way molecules interact (i.e. some 'noise', e.g. a mutation in a gene, does not necessary lead to loss of cellular 'information' - i.e. preservation of state and function) rather than flowing one way from some 'low level' set of molecules to some 'high level' ones. But I think the way he sets forth his argument is journalistic, rather than drily logical, and he could be faulted if judged on strict logical grounds."

Charles: Is there anything in the genome project that contradicts the Central Dogma as articulated by Crick ? :

"In 1957. Francis Crick, one of the co-discoverers of the importance of the genetic molecule DNA, called this hypothesis, the "Central Dogma" which :

"Stated that once "information" has passed into protein it cannot get out again. The transfer of information from nucleic acid to nucleic acid, or from nucleic acid to protein may be possible, but transfer from protein to protein, or from protein to nucleic acid is impossible."

Doesn't the result of fewer genes than expected, mean that the genotype is less detemining of phenotype than those who expected more genes thought, and that post zygotal environment plays a bigger role, but not that phenotype and experience cause changes in the genotype other than randomly with respect to adaptation to that phenotype or experience ? There is no contradiction of the socalled Central Dogma in the genome project results , or do we reinvestigate Lysenko ?

Charles


>>> pvh at egenetics.com 02/20/01 09:55AM >>>

I have recently come across a biologist who seemed to believe in a simplistic link between genes and function (he talked about things like 'genes for criminality'), but I must admit, they are not as common as popular science reporting (e.g. New Scientist) seems to suggest. Maybe it has got something to do with the speciality of the people around me - we're mostly gene expression people here - but the people I know in the field have:

1) Tended to emphasise for a number of years that 1 gene != 1 protein. There have been some pretty high profile papers on this over the years - e.g. the one on the stunningly variable Drosophila gene (something like 14 exons and thousands of different transcripts - it encodes for some receptor on a nerve cell as I recall).

2) Expressed at least some understanding that the existence of complex genetic regulatory networks (and regulatory networks elsewhere, e.g. the neural regulatory network involved in appetite) make simple judgements like the association between phenotype differentiation and simple (i.e. 1 gene) phenotype regulation is rare. It is precisely because of this realisation that microarray-based studies, where differential expression of many thousands of genes can be studied, are interesting. Even then, at the microarray tutorial I attended at ISMB last year, the speaker pointed out the limitations of probing for RNA expression levels and assuming they correlate with protein abundance.

So - I was rather surprised at the public furore over the 'small number of genes'. I'm not certain to what extent it expressed differences within the scientific research community, and to what extent it expressed differences within the 'scientific public intellectual' community. Figures such as Stephen Gould, and Richard Dawkins, appear to me, from the perspective of everyday scientific research, to be banner carriers for sets of values - I've known many scientists to be follows of Dawkins (the preferred option amongst the type of people who you tend to find in scientific research) despite a distinct lack of scientific correlation between his views and their own research work.

To me this pretty much proves that Science as an enterprise has a shitload of ideology mixed in. The kind of conclusions that are normally prefixed with "scientists have proved" tend in my mind to often have less evidence in their favour than I would normally consider scientifically acceptable.

-clip-

Peter -- Peter van Heusden <pvh at egenetics.com> NOTE: I do not speak for my employer, Electric Genetics "Criticism has torn up the imaginary flowers from the chain not so that man shall wear the unadorned, bleak chain but so that he will shake off the chain and pluck the living flower." - Karl Marx, 1844 OpenPGP: 1024D/0517502B : DE5B 6EAA 28AC 57F7 58EF 9295 6A26 6A92 0517 502B



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