No, not necessarily. You could quite conceivably believe that genotype absolutely determines phenotype. All that the two words describe is that there is the difference between the DNA which a particular organism possesses and the appearance of that organism - which is kinda obvious.
We happen to know experimentally, however, that genotype does not entire determine phenotype - for examples, see Lewontin and Levins' examples of the variation in number of segments in the eye of Drosophila, in 'The Dialectical Biologist'.
>
>
> 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."
>
Hm. There's a step missed out there - DNA to RNA. And yes, well, that
version of the Central Dogma has fallen prey to evidence years ago,
with the discovery of retro-viruses (e.g. HIV), which splice their
genetic material into DNA - i.e. information in the viral proteins
quite literally gets into DNA.
Also, the fact that regulatory networks control gene expression (which gene is 'switched' on - generally about 10% of genes are 'switched on' in any cell, as I recall), and the fact that the process of going from DNA to protein is complex, with many steps where intermediate steps get 'tweaked' (e.g. DNA is transcribed into RNA in a complex fashion - multiple different RNAs can be created from one gene. Also, there is 'post-translation' modification, which happens after RNA is translated into protein - but I don't know much about that) seems to me to be at odds with the CD - proteins and RNAs are involved in altering the information flow - to what extent this 'alteration' makes the whole CD thing much less useful as a model is a subject of debate. I tend to think the CD simply captures one process amongst the many processes which 'conserve information' in cells - others differ.
Also, I don't really see it as 'genome project' results which are challenging the CD here - a lot of the research going into the comments I'm making didn't happen as part of the Human Genome Project.
>
> 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,
I guess you could read it that way - if there was a 1-to-1 gene-protein link, you'd possibly have grounds for arguing that the gene expression process was straightforward and not a big influence on the information content on the cell. *In practice*, I haven't come across any real life scientists who argued that there was a 1-to-1 gene-protein link, certainly not at this stage of the game.
> 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 ?
Lysenko's arguments, as I've heard them laid out, involved not just post zygotal environment playing a role, but also the inheritance of acquired characteristics. If we didn't believe that post zygotal environment played a role, we wouldn't have a science of plant breeding - we could probably do to a have a more nuanced science like that (e.g. examining companion planting on a large scale), but I hardly think a return to Lysenko is on the agenda.
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