Charles Darwin, who greatly influenced the world with his evolutionary theories, went from a prospective preacher to a scientist.

Niles Eldredge, who influenced the world with his Punctuated Equilibrium theory, went from a scientist to a preacher.

His sermon focused on how Darwin formulated his theories.

This was the analogy doctoral candidate Shannon Steinfadt used to describe Eldredge’s speech yesterday in the Kiva. He was the keynote speaker at the 21st Graduate Student Senate Colloquium.

“We were sad that he didn’t talk about his own work,” said Steinfadt, who also presented at the Colloquium.

Eldredge gave a speech titled “Darwin: Discovering the Tree of Life,” detailing the experiences that influenced Darwin to develop his theories of evolution and natural selection.

“Darwin is still resonating in our 21st century,” Eldredge said, “while other great 19th-century towers are fading into the woodwork.”

Darwin began his interest in evolution when he charted the waters of the Southern Hemisphere on the H.M.S. Beagle, Eldredge said. It was in the Galapagos Islands observing an ostrich-like animal called a rhea that he came to two important conclusions: modern species replace older ones and similar species replace one another geographically.

Although Darwin had ground-breaking theories, he was nervous to publish them for fear that traditional scientists would reject them. Instead, he did in-depth studies on barnacles.

“I think that (the barnacles) were a space-filler,” Eldredge said. “They were not what he should have been doing — which was evolutionary research.”

Eldredge, along with his colleague Stephen Jay Gould, formulated the Punctuated Equilibrium evolutionary theory, which states that evolution occurs in rapid changes amidst long periods of stasis.

Eldredge is an adjunct professor at the City University of New York and curator in the department of invertebrates at the American Museum of Natural History, which currently hosts an exhibition on Darwin.

Edward Suarez-Moreira, colloquium chair on the Graduate Student Senate Executive Board, has been planning the event from the beginning of the school year. He said the GSS had to raise extra money to ensure a great keynote speaker.

“Most people celebrate a lot on their 21st,” Moreira said. “We decided to do the same. We aren’t giving away free booze; we decided to bring Dr. Niles Eldredge.”

Contact graduate studies reporter Michele Roehrig at [email protected].