On BioScience and Life and Such

Posts Tagged ‘phenotypic variation’

The rate of evolution/mutation/adaptation

In Uncategorized on January 3, 2008 at 1:48 pm

I came across this blogpost from evolgen which is a part of a discussion with John Hawks on increased rate of evolution. It seems to me that the term “neutral mutation” is central in this discussion. However, looking at the effect of Hsp90 as described in my previous posts (and future posts to come), – is it possible that some of these “neutral” mutations aren’t neutral at all, but rather deleterious or beneficial mutations masked by a heat shock protein ?

I am in over my head when it comes to in-depth analysis of population genetics data, but still, to me, – the action of mutation masking Hsp’s (if this is truly a valid evolutionary phenomenon) may seem to bridge these two opponents as well as solving a lot of other controversies surrounding the rate of molecular evolution vs. phenotypic/morphological evolution.

Evolution too fast for our genes to follow

In Uncategorized on December 20, 2007 at 1:41 pm

In the near future, the upcoming posts will center on Heat shock protein 90 (Hsp90) and how the function of this particular protein can explain rapid morphological evolution, or rapidly evolving phenotypic variation if you will. The topic and papers on it, are in my opinion hugely underrated. To me, until these papers came out, the extremely rapid (in a cosmic timescale) change in physical appearance that is seen in the evolution of species, was the major (only ?) valid argument contradicting Darwinian evolution through random mutations and genetic drift. This because genetic drift through random or even guided mutations, is just too slow to explain the evolution of such a vast spectrum of species as the one present on earth, in such a (relatively speaking) short time. The concept of masking mutations through the action of Hsp90 was an eye-opener and presented me with an extension to genetic evolution that explained rapid phenotypic change. Thank god(!) for this possible counter argument towards the missing link babble presented by creationists and their like. And it is surprising that these papers haven’t been used more in discussions concerning evolution. More details on Hsp90 to follow, but the fundamental paper is (not open access unfortunately): Hsp90 as a capacitor for morphological evolution Nature 396, 336 – 342 (26 Nov 1998).