>Other examples would include intragenic and intergenic supressors,
>which are far more common than reverse mutations. Of course,
>one could argue that these types of mutations restore the level
>of information to its initial state, that is, it's an increase relative
>to an earlier loss (thus it may not be a net increase).
On occassion, Spetner sweeps this under the rug by using that
argument. Other times, he invokes "directed mutations" as the
explanation -- That the genome is programmed to respond in
that way.
Another example of possible information increase:
There is the case where bacterial strains acquired antibiotic
resistance and later acquire secondary suppresoor mutations which
allowed the resistant strains to compete effectively with the
orginal, non-resistant strain in the absence of the antibiotic.
>A smart creationist might also focus on how we define this initial
>state and question how much information it contained and how it got
>there in the first place.
What I have seen among those who deny the examples we've given
is the claim that these mutations result in non-normal proteins,
abnormal responses or etc. The implication somehow being that divergence
from "normality" constitutes a loss of information. But that's only
if we define a particular state (the normal one) as having the
most "information".
>I personally think mutations that are selected can indeed increase
>information (especially when coupled to gene duplication), but I
>wonder if it's really a piss poor mechanism. If it is, and given that
>life is loaded with tons of information, there may be something solid
>behind all this informational chest-thumping.
Hard to say. It's not currently possible to track what happened
before the rise of the last common ancestor of all life. However,
given that we can often see relationships between extant sequences,
I don't think it's too far of a stretch to suppose that many of
the mutational & recombinational mechanisms we've observed could
contribute to much of the subsequent evolution.
For abiogenesis, I think there's a good reason for "informational
chest thumping". For subsequent evolution, that case is much weaker.
However, most creationists such as Spetner and our friends at the
Discovery Institute maintain that the bridge from apes to humans is
too great to be spanned by natural mechanisms; that the information
necessary to add the an ape's genome is too great. I would like to ask
them to point out the specific "information increases" needed for
ape -> human evolution, as reflected in specific protein and DNA
sequences. Once done, then we can debate.
Regards,
Tim Ikeda
tikeda@sprintmail.hormel.com (despam address before use)