Tuesday, May 29, 2007
Suck it or not- the fecudity anthem
For some time now, I have had passing discussions with a friend about the rift between Richard Dawkins and his "Selfish Gene" gene-selection theories and Stephen Jay Gould and his emphasis on organism/population selection. Quite often I hear of how Dawkins was somehow "discredited" some time after The Selfish Gene was published, but that the ideas were valuable insomuch as they were premature and published on the precipace of a great revolution in genetics and biotechnology. I attempted to argue this viewpoint and make generalizations about levels of selection for and in organisms but found myself talking in circles. So here is my blow-by-blow of the debate between two of the titans of evolutionary biology:
Dawkins- fetishizer of late model foreign sedans
The Selfish Gene put forward a gene-centric view of evolution, one which describes genes, rather than organisms as the unit of selection. In short, Dawkins says that a gene, the material which gives an organism a particular characteristic (phenotype), is responsible for driving evolution. The gene, through random chance and its ability to confer preferential fitness to its vessel, survives. Although the genes themselves do not "behave", the gene level is the level of organization where selection acts. Organisms are merely "survival machines" for genes.
This explaination became particularly popular because it made sense of a number of oberved but until-then counter-intuitive phenomena, namely kin selection. Preferrential and protective treatment by siblings seems to fly in the face of an organism-based selection theory but makes a great deal of sense when you explain such behavior as a protectiveness for genes. After all, your genome is more similar to your siblings than it is to any body else's. Essentially, Dawkins describes such behavior as being the natural consequence of genes building machines to protect like genes.
Behaviors or charicteristics that cannot be classified as strictly phenotype-derived are put under the classification of "memes"- info genes- where units of information are culturally transmitted.
Gould- thug denizen of bus station fashion
Gould was a paleontologist and curse-era Red Sox fan, so naturally he took the long view on biological issues. He believed that Dawkins was using a sort of "Darwinian fundamentalism" that was not unlike Social Darwinism and Genetic Determinism of times past. Even though Dawkins makes biological/mathematical justifications of pacifism in The Selfish Gene, Gould dismissed these examples as retrofittings of theory to conform to existing society as viewed through the Dawkins' own disposition. Furthermore, Gould's broad based view of cladistics (the science of biological classification) over geological history led him to believe that the expansive cascades of interactions (in life and in development) between broad groups of species or organisms within a species could not be explained so simply without empirical evidence. Furthermore, Gould felt that Dawkins did little to explain the herky-jerky stops and starts of species (and gene) proliferation at varying rates through geologic time. Dawkins really presents very little empirical evidence for his theorizing in The Selfish Gene, written before the modern era of genetic biotechnology.
In short, Gould felt that Dawkins was making a mistake by ignoring (as he saw it) the vast complexity of biological interactions in favor of a more unifying, dogmatic view of evolution wrapped in appealing and sexy rhetoric.
My take- makin peace like Tookie
Dawkins theory is sexy, Gould's theory is not, by virtue of its age. However, it's hard to assign (in my mind) too much agency to genes. Genes are the agents of evolution, phenotypes are the agents of selection. However, genes are pretty passive actors- they are subject to random mutation and crossing over during meiosis. It's kind of a chicken and egg argument in my mind- do genotypes passively control the preservation of phenotypes or do phenotypes actively control the preservation of genotypes? Without one, there is no other.
I understand Gould's concern about the retrofitting of a theory to confirm observed social phenomena and the potential distortion that could be wrought by those who seek to use "Darwinism" to confirm social beliefs. However, that point is largely moot- social liberalism, although admirable in my mind, cannot be used as a scientific defense, only empirical evidence can.
I'm pretty rusty on my evolutionary theory, so if anybody has any corrections or opinions they'd like to offer, have at it. I need to get my brains back in shape for when I return to school, and this is as good a forum as any.