Actually, there are cases where duplication alters the function of
the gene.
> The duplicate might first lose some of its function, but then it has
> to build up something new. To use our example of reducing the
> specificity of the gene, it might be beneficial first to reduce
> specificity so as to grant the enzyme some activity on a new
> substrate.
The "specificity of the gene" is related in some way to the "specificity
of the enzyme" it encodes? Not necessarily; to me this sounds like using
the term "specificity" for separate domains.
> But that can be only the beginning. The second job is to
> have random mutations increase the specificity of the enzyme for the
> new substrate. The first is easy and can be done quickly. The second
> is much harder, and we have no evidence that it has ever occurred,
> in spite of the necessity for orders of magnitude more of this kind
> of mutation than for those of the type that disable a gene."
Q: In the case of gene duplication + divergence which leads to an
new or altered capability, which organism contains more information:
a) The original organism prior to the duplication?
b) The later organism with the duplication?
Comment:
If you follow old posts in bionet.info-theory you will find
many of the people there scratching their heads about using
binding or catalytic specificity as a criterion for genomic
information. There are mutations found which "increase the
specificity" of enzymes ("increase" being understood in the
Spetnerian sense of the term). The respondents in b.i-f. also
questioned whether many of Spenter's assumptions about mutations
& evolution were correct.
See: (keyword = "spetner", forum = "bionet.info-theory")
http://www.deja.com/getdoc.xp?AN=427543580&fmt=text
http://www.deja.com/getdoc.xp?AN=427103016&fmt=text
http://www.deja.com/getdoc.xp?AN=427088150&fmt=text
I have also provided journal references as well in
previous notes to this group.
I thank Spetner for providing us with a synopsis of his
information measurement. His response matches exactly
what I had gleaned from his previous writings (I was
worried that I'd missed something important).
Regards,
Tim Ikeda
tikeda@sprintmail.hormel.com (despam address before use)