How much of a human brain can you put into a mouse? Is there any limit? Is there a point where it begins to look more like a human brain than a mouse brain?"
Before the 200 assembled students could ask Irving Weissman questions about the lecture he'd just given on transplanting stem cells, the pathology professor was firing off some thought-provokers of his own. "What is the architecture of the quality of human-ness?" he continued. "What is it that makes us human?"
Weissman, md '65, has been a frequent guest speaker for Bioethical Issues in Human Biology in the nine years it has been offered. Not surprising, since he deals every day with the kinds of moral, ethical and religious issues the course is designed to address.
The yearlong course complements the core sequence in human biology, which introduces students to the relationship between biology and social science. "I tell the students they will create the future because the decisions they make about technology will govern how it is used for hundreds and maybe thousands of years," says the instructor, William Hurlbut, a physician and lecturer in human biology. "Questions and concerns raised now will either shut science down or open it up."
Hurlbut, '68, md '74, begins fall quarter with a look at humans' place in the universe. This autumn, he tapped Andrea Nightingale, '81, an associate professor of classics, to talk about nature as it's been defined from Heraclitus through the postmodern age.
Throughout the year, Hurlbut calls on specialists from around the University to share their best thinking on ethics and human nature, the human genome project, genetic testing, and religion and evolution. "I try to bring in top scientists who can give us a solid understanding of the science behind the technology and who can also talk about where we come from, what we're here for, where we're heading and what we want in life," Hurlbut says. By spring quarter the class is digging into questions of animal experimentation, biowarfare and ethical dilemmas in treating premature babies.
Hurlbut tells students he wants no references or footnotes in the term papers he assigns--just original thought. "Draw on your own personal perspectives and your religious or philosophical beliefs," he says.
After graduating from Stanford Medical School, Hurlbut studied theology, and he touches on that background in the lectures he presents on human purpose, eugenics and beauty. He also draws on his own experience as the father of a child who was born with severe brain damage.
"I try to keep the science solid and objective, but you want to show students just how amazing the truth is at times," Hurlbut says, with echoes of astronomer Carl Sagan's contagious enthusiasm. A speaker on cosmology once showed the class a movie of "galaxy after galaxy" taken from the Hubble Space Telescope. The view was "from a tunnel so small that it was the size of the crossing of two needles held a yard away from your eye," Hurlbut recalls. "It gave us a sense of the universe being deep and dense and full of reality."
The toughest part about teaching the class? Getting students to go home. After Weissman finished his talk on stem-cell research on a February night, the hour crept past 9 p.m., then past 9:30. And still the students stayed, asking questions about whether stem cells could be used to grow donor organs and how Weissman could justify animal experimentation in his lab.
"They never want to stop talking about these issues," Hurlbut says. "That's one reason we meet in the evening, when they're perhaps more philosophical and they can go back to their dorms and just really think."
