Why Would Science Daily Use Such a Headline

[a different tim]

bryantee wrote

Just a quick brainstorm brought to my attention that punctuated equilibrium and gradualism can both occur. The main factor being the environment. If the environment changes requiring individuals to posses a certain trait, those without the trait will quickly die and those with will find their genes rapidly spreading through the population. Since the environment is always changing evolution will always be occurring, be it gradual or in quick spurts. But hey, that's based on no evidence - just a hypothesis I suppose. :P

I think PE was always supposed to be "rapid gradualism" although Gould flirted with saltation in the 80s. What you're saying is pretty much the Dawkins view - evolution is always happening, sometimes slowly, sometimes quickly. Gould argued otherwise - that long periods of stasis were punctuated by bursts of "normal" evolution. To Gould, these periods of stasis were something that needed explaining.

It's a bit tricky because in Gould the whole question is tied up with his views on selection - he wanted to show that species selection made sense, and that species were "Darwinian entities" that have "descendants". This only makes sense if you interpret the fossil record Gould's way - that between bursts of evolution that lead to speciation there is genuine stasis, and the normal sort of variation in a species is not the same thing as speciation. The Dawkins view makes sense if you argue that selection only takes place between individuals or (if you're being a strict Dawkins-ite) between genes.

This kind of "rapid gradualism" is however different from the saltationist view that I think the prof is giving in the quote that started this. If pharyngula answers Bacon I'd like to know what PZ thinks.