The New York Times and The Wall Street Journal are taking notice of Biology major Sean Carroll ’03 (left, sitting), a graduate research fellow in Biology at the University of Oregon, after he co-authored in the journal “Science” a controversial article about evolution. The magna cum laude graduate, along with researchers Jamie Bridgham and Joe Thornton, examined ancient genes from extinct animals in order to study how they evolved on a molecular level.

Charles Darwin proposed that evolutionary changes are formed by “numerous successive slight modifications,” but critics of evolution say some biological mechanisms are simply too complex to have been created by anything but a higher being.

“The purpose of our paper was not to go fisticuffs with the anti-evolutionists, but merely to address an important question in biology – how the evolutionary process generates molecular complexity,” Carroll says. “It just so happens that biological complexity is a particularly touchy subject to some.”

One of those biological complexities is that of the relationship between hormones and their receptors. Receptors and hormones work together to carry out particular functions.
In humans, Carroll explains, it is not immediately clear how you could evolve receptor or hormone separately because a loss or malfunction of either causes disease. What results is suggestive of a chicken or the egg dilemma – how can a new hormone evolve without a receptor for it to bind, and vice versa? Some say that the hormone-receptor partnership is too complex to have been created by stepwise changes through the evolutionary process.

Yet, they did evolve separately, according to Carroll, Bridgham and Thornton. The trio recreated a 450-million-year-old receptor and found that it was activated by a hormone that had yet to evolve. The receptor or “lock” was “preadapted” to fit a “key” that had yet to evolve, says Carroll. This showed how a complex molecular partnership, like that of a hormone and its receptor, could have evolved by making slight changes to pre-existent structures and co-opting them for new functional roles.

Carroll credits professors at McDaniel with inspiring him to achieve in the sciences.

“All the professors mentored me, both within and outside of the science department,” he says. “Drs. Mitschler, Long, Iglich, Smith, and Paquin particularly helped to nurture my scientific interests. I feel well prepared to succeed at anything I put my hands to.”

Carroll is earning his Ph.D. in Ecology and Evolution.