Q&A: Sean B. Carroll

Fish gotta swim, birds gotta fly, but how did they develop the fins and wings to do so? Sean B. Carroll, a leader in the new science of evolutionary developmental biology, offers some answers in Endless Forms Most Beautiful (see review, p. 105).

For many, Evo Devo will be a new term. Can you give us a brief explanation?

Evo Devo is our catchy shorthand for the evolution of development. This is the science concerned with the making and evolution of form. There is an intimate connection between development, the process of making a complex creature beginning with a simple egg, and evolution. All changes in form are due to changes in development.

How did you first become involved with this subject?

Since I was a kid, I have, like most people, been drawn to animal patterns—butterflies, zebras, leopards, etc. When I started out in biology, we knew nothing of how patterns are made, and that was the focus of the first phase of my career. Once some of the basic rules of development were figured out for a few species, I started pursuing how butterflies and other animal patterns evolve.

Evo Devo is described as "the third revolution" in evolutionary biology, which leads us to ask what's next?

I see three big questions on the horizon. The first concerns the origins of human form and talents. How did our big brains, body anatomy, and speech evolve? Second, one of the surprising new facts from Evo Devo is how often evolution repeats itself in completely different animals and plants, sometimes in minute detail. I think that understanding how and why this occurs will have profound implications. Third, it is a complete mystery how new behaviors evolve. Think of the amazing behaviors in the animal kingdom—bird songs, great migrations, parental care. This is a wide-open frontier.

On a related note, recent news reports suggest that evolution is being taught less in schools these days. Is that surprising to you?

It is astounding. The advocates of teaching "alternatives" to evolution deny its reality, which in turn requires a denial of the past 150 years of fundamental progress in biology and geology. The young earth creationists, Intelligent Design advocates, and other opponents of evolution have been given too much ink, air time, and consideration by school boards.

I believe that an alliance of scientists and mainstream clergy could do a lot to correct the impression that this is an issue of science vs. religion. The teaching of evolution belongs in the science classroom, the study of religion belongs elsewhere.