In 2003, before he was bestowed the responsibility of selecting spring graduation speakers, Chancellor Holden Thorp was charged with filling venues much smaller than Kenan Stadium.

Then the director of the Morehead Planetarium and Science Center, Thorp looked to E.O. Wilson, a Harvard University professor whom he met in 2002, to deliver a speech at the George Watts Hill Alumni Center titled “Biodiversity and the Environment.”

“We had all three rooms open and filled with chairs, and the place was packed,” Thorp said of the December speech. “There was a line around the block.”

Seven years later, Thorp sought out Wilson yet again, this time for the May 8 commencement speech.

A two-time Pulitzer Prize winner, Wilson began his career studying ants in the South Pacific and southern United States before going on to apply his findings to formulate theories that bridged the gap between the humanities and science. Wilson is widely known within the scientific community for fathering the field of sociobiology — a field that intertwines several scientific disciplines to explain the social behavior of species based on their Darwinian advantages. In 1975, he authored “Sociobiology: The New Synthesis,” a book that stirred bitter controversy for explaining the role of biology in human behavior.

“He is an incredible advocate for the importance of biodiversity and protecting the planet and the species that inhabit it and the difficult times that we are facing,” said Thorp, who will preside over the 9:30 a.m. ceremony. “He’s the most articulate environmentalist of our time, so he’s a great choice … I’m sure that many of the students who will be graduating will be going to green jobs, and so what better way to send them off than to have Ed Wilson as the speaker?”

With Wilson — whose name appeared only on a list of considered speaker candidates — Thorp strayed from the list of recommendations presented to him by the commencement speaker selection committee, a group of students and administrators that Thorp consults for the selection. Following the tradition for such ceremonies, Wilson will not receive compensation for the speech.

“It’s an honor to give the talk, and speakers normally receive an honorary degree,” Thorp said. “And we expect people who come to do it to feel that that’s more than compensation enough.”

Wilson, a Pulitzer Prize winner and famed biologist, mirrored the committee’s top-ranked choice, who was another world-renowned scientist, said Ron Strauss, executive associate provost and the chairman of the speaker selection committee.

Strauss could not reveal the name of the committee’s top choice, saying that the task of bringing that speaker to UNC for the 2012 commencement ceremony will be the “first topic of conversation” for the next speaker selection committee.

“The person who was top-ranked just wasn’t available,” he said. “It wasn’t a matter of second choice. I don’t want to give the seniors the impression that we have a second-choice candidate. That’s just not the case.”

Committee members unanimously supported Wilson but were initially concerned with his lack of name recognition outside the scientific community, Strauss said. Internationally known speakers, including the prominent religious and political figure Desmond Tutu and best-selling novelist John Grisham, spoke at the spring commencement ceremonies in 2009 and 2010, respectively.

“That was a caveat that was stated — that sometimes name recognition is a nice thing,” he said.

But those concerns were largely allayed, Strauss said, after committee members researched Wilson and watched his speeches online.

“E.O. Wilson made this movie called ‘Lord of the Ants,’” said senior class president Liz Deane, who is one of five student representatives on the 10-person speaker committee. “I don’t think his speech will be on ants, but his work is more interesting than I thought it would be.”

Deane and Strauss said one of the weaknesses of the University’s selection process is its late start.

Deane said she and other committee members will stay on through the end of the semester to avoid the same issues they faced in the fall.

“In the future, we need to start earlier looking for a speaker,” she said. “It’s hard to get them to commit when you only ask them in September or October.”

Contact the University Editor at university@dailytarheel.com.