Wednesday, February 18, 2009

Stephen Jay Gould Challenged the Modern Synthesis

As most of you know, Gould (1941 - 2002) was a critic of the hardened version of the Modern Synthesis. He thought that evolutionary theory needed to be updated to include some things that the originators of the Modern Synthesis were unaware of—or rejected prematurely.

His paper in Science in 1982 reached a wide audience and most biologists first became aware of his challenge by reading this paper (Gould, 1982) [read it here—if you have a subscription to Science].

But two years earlier, Gould published a more scholarly critique in the journal Paleobiology (Gould 1980). The opening sentence of the abstract throws down the gauntlet.
The modern synthesis, as an exclusive proposition, has broken down on both of its fundamental claims: extrapolationism (gradual allelic substitution as a model for all evolutionary change) and nearly exclusive reliance on selection leading to adaptation.
Ryan Gregory discusses this paper in detail on Genomicron [Gould (1980)]. If you want to be informed in this debate you absolutely must read what he has to say about this key paper in evolutionary theory.

Ryan discusses three important myths about Gould. The false myths are: (1) he rejected natural selection, (2) he wanted to overthrow the Modern Synthesis, (3) saltation and punctuated equilibria are somehow connected.

The last myth is so widespread that people as diverse as Jarry Coyne, Greg Laden, and Daniel Dennett have gotten themselves hopelessly confused about punctuated equilibria by not reading carefully [see Macromutations and Punctuated Equilibria]. They should know better.

They will know better (I hope) once they have read Ryan Gregory's posting.

Today, there are many people who want to change the Modern Synthesis. Advocating some new addition to evolutionary theory has become a minor industry—aided and abetted by science journalist who are more interested in controversy than accuracy. But those failings should not blind us to the very legitimate challenges to the Modern Synthesis raised by Gould over twenty-five years ago.

It's disappointing that most of those challenges are still not understood by biologists. Read Ryan's summary of Gould (1980), and learn.


[Image Credit: Photograph of Stephen Jay Gould by Kathy Chapman from Lara Shirvinski at the Art Science Research Laboratory, New York (Wikipedia)]

Gould, S.J. (1980) Is a new and general theory of evolution emerging? Paleobiology 6:119-130.

Gould, S.J. (1982) Darwinism and the expansion of evolutionary theory. Science 216:380-387.

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