Friday, February 08, 2008

Hsp90 and Evolution

The SciPhu blog has an interesting series of posts on the chaperone Hsp90 and it's effect on evolution. Here's the list of article with the links.
My contribution to JustScience 2008 will be a review on a protein with the potential to transform evolution theory as we know it today. The review will be divided into 5 separate blog posts:
  1. Introduction to Hsp90 and evolution (this post)
  2. Presenting the Hsp90 protein
  3. How can chaperones act in evolution
  4. Evidence for Hsp90 involvement in rapid evolution of new traits
  5. Summary
I don't agree with the main conclusion that Hsp90 has an important role in evolution but the case is well presented. Anyone who wants to know more about hopeful monsters should read these articles.

UPDATE: My comment above may be misinterpreted. Sciphu may be right about "hopeful monsters" but he's dead wrong to confuse punctuated equilibria and macromutations. He makes the same mistake that others routinely make [Macromutations and Punctuated Equilibria].

We often criticize the creationists for misunderstanding punctuated equilibria and confusing it with the lack of transitional fossils. I think we should be just as hard on evolutionists who make the same mistake.

The figure shows the structures of Hsp90 from yeast, dog, human and E. coli [HSP90 Structure]


  1. Hsp is also being a promising target for small molecule inhibitors now. Wasn't it Susan Lindquist who discovered something about Hsps and cancer last year? Don't exactly remember

  2. "I don't agree with the main conclusion that Hsp90 has an important role in evolution."

    Why not?

  3. george smiley asks,

    "I don't agree with the main conclusion that Hsp90 has an important role in evolution."

    Why not?

    It doesn't make a lot of sense.

    I'm sure there are a few occasions when important mutations are phenotypically masked in the presence of Hsp90 (or any other protein) only to be exposed at the appropriate time. I don't think it's appropriate to elevate those rare occasions to a general theory about an important role for Hsp90 in evolution.

    I certainly don't think it's appropriate to be talking about "a paradigm shift in evolutionary biology."

  4. I have replied to your comment (pasted below), I am looking forward to discussing this further. For starters, why do you say that these are rare events ? It is pretty clear to me from the published material that when the conditions simulate stress (temperature rise or drugs), these events aren't rare at all, but rather very common.

    My reponse on the sciphu blog:
    "Thank you for your comment and thank you for referring to these posts on your website. Now..., my concept of punctuated equilibria is,.. put bluntly: "evolution in bursts" ....period. The link between Gould and hopeful monsters may be wrong, but that does not change the fact that there is a need to explain rapid non-linear evolution. The reason creationists use these arguments is not mainly because they misunderstand Gould's theories, but because there is a real lack of credible, solid scientific explanations for evolution in bursts. Explaining evolutionary change as the result of a slow, random and constant mutation rate is just not sufficient. Your statement "In most cases, it takes an expert to recognize that speciation has occurred in the fossil record." underscores this point, since the diversity and plasticity in nature is obvious to even the unschooled child. The argument is otherwise irrelevant since it is merely a description of skill requirements in paleontology/biology. Canalization through Hsp90 is a credible, scientific hypothesis explaining the world better than the prevailing interpretation of evolution theory. I am looking forward to the canalization hypothesis being challenged, but in order for that to happen it must be accepted as a valid theory. "