Feedback - Week 6 - JOURNAL CLUB - de Visser et al (2003)
Genetic robustness:Katrina pointed out some flawed arguments in the review, or instances of lumping concepts together incorrectly. In particular were the concepts of plasticity and varience which were getting confused.
One thing I raised, Which Katrina countered (apologies if my terminology is a bit off), is I've often thought that any genes that are not being fully expressed due to some buffering system as discussed in this paper would be come "deleted", or at least decoupled from the ancestral phenetypic character it is now not actively used for. This is probably because I'm used to seeing the "use it or loose it" effect in functioanl anatomy (eg wings reduced or lost in some animals, where there's no longer natural selection pressures maintaing its normal function). I assumed if the expression of a gene was being buffered over enough generations, the gene is no longer subject to natural selection to maintain its role in a functional workable system, and could become a "non functional intron sequence" from random point mutations, or possibly changes in the parts of the "genetic network" that are buffered with it could end up excluding the gene from is role in effecting the phenotypic character. I can see that through pleiotropy, its possible the gene's role elsewhere in other characters will save it from "deletion" or prevent radical change - so that elsewhere the expresion of the gene is regulated by natural selection. Katrina said that the "use it or loose it" effect wouldn't work like this on genes, as the buffer system is an active integrated part of the system too, and only buffers the products of the "normal gene", and any radical change will sidestep the buffering system, be expressed, and therefore presented to natural selection and mostly likely removed from the population (as most mutations are deleterious).
We decided to go with another paper that Katrina has noticed flaws in for the next JOURNAL CLUB meeting.
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posted by Chris Glen @ 1:33 PM
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