Evo-Devo in U.S News and World Report
I just came across this interesting article in US News and World Report about biologist Sean Carroll of the University of Wisconsin, Madison. Carroll's recent evo-devo book Endless Forms Most Beautiful is excellent. I will have more to say about it in some future post.
For now, here are two excerpts from the U. S. News article:
We're living at a strange moment in America. Once again, evolution is becoming a controversial topic. But while school boards are revisiting the 19th-century debate over whether evolution even happens, 21st-century scientists are beginning to show exactly how the natural phenomenon works. Using the powerful tools of molecular biology and comparative genomics, they're finding specific changes in the DNA that can account for 17,000 species of butterfly or why insects have only six legs instead of a dozen. And while some 55 percent of Americans balk at the idea that humans evolved at all, analysis of the genes that build our bodies shows our clear kinship not just to the apes but all the way back to bugs, worms, and beyond. Along the way, scientists are starting to find concrete explanations for everything from our large brains to just exactly how the fruit fly--or the leopard, for that matter--got its spots.
That discovery pointed to the deep connections between all animals and helped scientists work out the complex details of development. But it also raised a new problem: If key developmental genes have remained largely unchanged throughout evolutionary history, how can we account for all the differences, great and small, between different species? In some cases, the answer turned out to be a process of duplication and innovation. Several key points in animal evolution are associated with an increase in the number of developmental genes. The resulting redundancy in the control system, Carroll says, allowed evolution to “experiment” with new developmental programs and body forms, allowing vertebrates to develop distinctive features like skulls and jaws, for example, without hopelessly messing up other body parts.