Punctuated Equilibrium

Posted by | July 19, 2009 | darwinism | No Comments

I never quite understood the beef between Dawkins and Gould over punctuated equilibrium, however the notion that just because species flourish at different rates does not mean that DNA mutation does. (I need to double check to see if that was Dawkin’s point. )
To illustrate this consider a sand pile and the mini-avalanches that happen as sand is poured on the top at a constant rate. The rate of the pouring of sand may be constant but the avalanches will be varied – some big, some small, following a power law distribution.
In evolution, a constant rate of change to genotype may create periods of rapid change and periods of little change in phenotype – punctuated equilibrium. The gradualist evolutionary mechanism of neo-Darwinism is not challenged by this.

(update – am checking the Gould vs Darwin debate – the literature is not very succinct, surely I don’t need to read an entire book to see what the exact difference of opinion was?
It seems to be this: Dawkins figures that all complexity at the level of species, how they interact appear and disappear within a changing environment can be explained by natural selection operating at the level of genes. There doesn’t seem to be a simple explanation of what Gould thought (perhaps that’s why there are no 3 line explanations). My instinct is that Dawkins is right and analogies abound in terms of simple processes producing complex interactions – like the 3 planet motion).