( raction of selection and what we call g...)Ernst Mayr's theory illustrated in genetic epidemiology studies

raction of selection and what we call genetic drift could cause what he called a genetic revolution, a rather radical adaptive change that would be unlikely to happen if you had just natural selection in a large population alone," Templeton said. "It's kind of like you stirred the pot at random, but then it goes off in a new direction due to natural selection.

So, that was a very controversial idea when it was introduced. I corresponded with Mayr for 25 years, and he considered it to be one of his very best ideas."

Templeton said that there are still a lot of biologists who don't like the idea of genetic drift, but he thinks that they miss two very important concepts of Mayr's argument. One is that genes interact with one another extensively, and that with the establishment of an interaction system, it's inevitable that once frequencies are changed, the direction of natural selection changes.

"We now know from my CAD work and other genetic epidemiology studies that we find these kinds of genetic interactions all over the place, so that modern molecular biology has confirmed Mayr's idea of genetic architecture," Templeton said. "Given that you have this interaction it's inevitable that a random process like drift will interact with natural selection strongly to spark new directions of evolutionary change."

The other thing detractors object to is the random aspect of evolutionary change.

"Those uncomfortable with Mayr's theory don't take into account that under his model, it's the interaction of the random that forces the natural selection that creates the evolutionary change," Templeton said. "Although the initial founder effect is somewhat random, the changes that emerge out of it are highly non-random and are very much directed by natural selection and are adaptive.

"It's incorrect to portray genetic revolution as just a random speciation model. It's a process that is very strongly driven by natural selection, b
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Source:Washington University in St. Louis

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