AAAS Topics Span Broad Range

This year's annual meeting of the American Association for the Advancement of Science attracted about 6,400 scientists, science journalists, and others to Boston Feb. 14-19. Topics of discussion ranged from bioterrorism to dinosaurs to ice cream to bird brains (www.aaas.org/meetings). Following are notes on just a few of the sessions.

As neuroscientists strive toward unearthing the very roots of human emotion and thought, the ethical and legal ramifications could be enormous. One AAAS symposium organized by the editors of Neuron explored the potential "societal impact" for such research. Steven Hyman, former director of the National Institute for Mental Health, contrasted drug addiction with schizophrenia to illustrate the complex dynamics between genes and the environment, and emphasize the importance of a better public understanding of that interaction. While both conditions have environmental and genetic determinants, only the pathogenesis of addiction clearly depends on certain behaviors—behaviors that can actually alter one's brain morphology and hence strengthen cravings. Princeton University professor of psychology Jonathan D. Cohen presented brain imaging findings that may empirically demonstrate the influence of persons' emotional responses on moral judgments. University of Pennsylvania bioethicist Arthur Caplan argued that the development performance enhancers, used to accentuate anything from memory to sex, should not necessarily be considered morally repugnant, assuming they're deemed safe. Philip Heyman of Harvard Law School explored the possibility that neuroscience tools might one day be applied to legal matters, perhaps to scientifically demonstrate whether a suspected criminal was unable rather than unwilling to control himself. "Maybe brain science will be able to tell the difference some day," suggested Heyman.

Scientists should do more to encourage adolescents to embrace science careers, asserts Dean Kamen, the founder of FIRST (For Inspiration and Recognition of Science and Technology), a Manchester, NH, nonprofit organization that sponsors nationwide competitions to solve engineering and design problems. "The science community gets a D in being socially responsible," he told a 150-member audience at the AAAS meeting. Also the president of the Manchester-based DEKA Research & Development Corp., Kamen spoke from atop a Segway, the electronic human transporter DEKA patented in 2001. He urged more university science departments to participate in FIRST competitions. At these regional and national events, high-school teams and their corporate sponsors compete to build robots. Each team works with the same materials and displays its success during a robotic game of catch. The robotic showdowns are designed to convince young people that science can be as exhilarating as are professional sports. For some students, such as Laura Lyons, whom Kamen described as homeless when she entered FIRST, the competitions provide reason to stay in school. Through FIRST, Lyons developed a relationship with engineers at NASA, where she worked for two summers. She now attends Princeton University, with aspirations of becoming an astronaut.

Scientists estimate that 99% of our genes have animal homologs. The remaining 1%—approximately 300 genes—are uniquely human. "That's not a lot of genes, but it ain't chopped liver either," says Maryellen Ruvolo, Harvard University anthropology professor and one of five speakers at the AAAS's Genomics Approaches to Human Evolution symposium. Ruvolo described the molecular evolution of a newly evolved gene that codes for a subunit of choriogonadotropin (CG), a hormone that plays a key role during pregnancy. The theory is that this gene evolved 40 to 60 million years ago in the more recent primate lineages, including humans. Older primates, such as tarsiers and lemurs, and mammals do not have the gene. Its evolution appears to be correlated with spectacular adaptive changes in uterine biology and illustrates how comparing the molecular and morphological evolution can reveal important evolutionary changes among primates. The same approach could be used to better understand the 1.5% divergence between humans and chimps. Protamine, for example, is a sperm protein with a remarkable 16% amino acid difference between humans and chimps, according to one of Ruvolo's co-speakers, Caro-Beth Stewart of the State University of New York, Albany. Although its adaptive significance is unclear, the rapid evolution of protamine serves as yet another example of how genomic data may ultimately enable researchers to unearth the genes that make people uniquely human.

To know Escherichia coli strain K-12 is not necessarily to know its relative, the notorious burger-defiling strain 0157:H7, said Claire Fraser, president of The Institute for Genomic Research, to a symposium at the AAAS meeting. The differences between their microbial genomes are vast and varied, she said. Part of an all-star lineup to discuss bioterrorism, Fraser began with an update on the mysteries that continue to unfold as microbial genomes are sequenced. So far, GenBank boasts 59 prokaryotic genomes, and since Haemophilus influenzae started the parade in 1995, the unveiled diversity of the microbial world has been astonishing, she said. Each genome initially yields a "parts list" of basic functions. Typically, 40% to 50% of its protein-encoding sequences are unknown—a proportion that has barely dropped as more genomes join the list. Even microbes long-thought to be cousins are turning out to be diverse. "Vibrios cholerae and E. coli appeared to be closely related in terms of their rRNA sequences. But nothing could be further from what we thought," Fraser said. Comparing E. coli strains—lab standard K-12 and the toxic variant—was even more surprising. Said Fraser, "Sequencing the second E. coli genome revealed that these two strains differ by more than a million base pairs." Lateral gene transfer and gene loss contribute to the striking distinctions.

To remain competitive, research universities must effectively manage diverse interdisciplinary teams, but few US institutions have built such successful interchanges, according to participants in the AAAS symposium, 'Coping with Complexity, Managing the Academic Research Enterprise.' "There has been a transformation in the way universities are designed," said Irwin Feller, an economics professor at Pennsylvania State University, who is researching the interdisciplinary programs at several US institutions. The "rearrangement" in the life sciences in particular, with biologists connecting with computer scientists and engineers, reflects the pursuits of only the most successful universities, such as the Massachusetts Institute of Technology and Carnegie Mellon University. But for others, interdisciplinary teams still remain only part of a strategic plan that may never see implementation. "One sees a strong commitment to interdisciplinary work [from funders]," he adds. "But plenty of programs have lapsed once the money runs out." Many universities have also failed to create engineering faculties and student bodies that mirror the general population, according to Daryl Chubin, senior vice president of research and policy for the National Action Council for Minorities in Engineering (NACME) in New York City. "Under-representation should be seen as a combination of organizational failure and individual choice," Chubin told symposium participants.