Morgana and melusin: Two fairies chaperoning signal transduction

Chaperones and scaffold proteins are key elements involved in controlling the assembly of molecular complexes required for coordinated signal transduction. Here we describe morgana and melusin, two phylogenetically conserved chaperones that cooperate with Hsp90 and regulate signal transduction in important physiopathological processes. While morgana is ubiquitously expressed, melusin expression is restricted to striated muscles. Despite high sequence homology, the two chaperones have distinct functions. Morgana controls genomic stability by regulating the centrosome cycle via ROCKII kinase. Melusin, however, organizes ERK signal transduction in cardiomyocytes and regulates cardiac compensatory hypertrophy in response to different stress stimuli.     

Gould on Laws in Biological Science

Are there laws in evolutionary biology? Stephen J. Gould has argued that there are factors unique to biological theorizing which prevent the formulation of laws in biology, in contradistinction to the case in physics and chemistry. Gould offers the problem of ’’complexity‘‘ as just such a fundamental barrier to biological laws in general, and to Dollo‘s Law in particular. But I argue that Gould fails to demonstrate: (1) that Dollo‘s Law is not law-like, (2) that the alleged failure of Dollo‘s Law demonstrates why there cannot be laws in biological science, and (3) that ’’complexity‘‘ is a fundamental barrier to nomologicality.     

Un portrait de Stephen Jay Gould

A portrait of Stephen Jay Gould. From 1982 to 2002, as Stephen Jay Gould's translator and friend, I came to greatly value his personal qualities as a man, and admire him as a fine scientist and theorist. To cite this article: M. Blanc, C. R. Palevol 2 (2003).     

Gould talking past Dawkins on the unit of selection issue

My general aim is to clarify the foundational difference between Stephen Jay Gould and Richard Dawkins concerning what biological entities are the units of selection in the process of evolution by natural selection. First, I recapitulate Gould’s central objection to Dawkins’s view that genes are the exclusive units of selection. According to Gould, it is absurd for Dawkins to think that genes are the exclusive units of selection when, after all, genes are not the exclusive interactors: those agents directly engaged with, directly impacted by, environmental pressures. Second, I argue that Gould’s objection still goes through even when we take into consideration Sterelny and Kitcher’s defense of gene selectionism in their admirable paper “The Return of the Gene.” Third, I propose a strategy for defending Dawkins that I believe obviates Gould’s objection. Drawing upon Elisabeth Lloyd’s careful taxonomy of the various understandings of the unit of selection at play in the philosophy of biology literature, my proposal involves realizing that Dawkins endorses a different understanding of the unit of selection than Gould holds him to, an understanding that does not require genes to be the exclusive interactors.