A Summing Up, and a Look Ahead, in Biology

Illustration: A. Canamucio Biology today, though uncovering more and more knowledge at an amazingly rapid rate, is more specialized, fragmented, and incomprehensible to the layperson than ever. Part of this is inevitable, due to the rapid expansion of knowledge brought about by the great advances of molecular techniques. However, disciplinary boundaries are also part of the problem. Could we not try to overcome such obstacles and integrate some of the many strands of knowledge, to see what we mi

Jun 12, 2000
Patrick Wigge

Illustration: A. Canamucio
Biology today, though uncovering more and more knowledge at an amazingly rapid rate, is more specialized, fragmented, and incomprehensible to the layperson than ever. Part of this is inevitable, due to the rapid expansion of knowledge brought about by the great advances of molecular techniques. However, disciplinary boundaries are also part of the problem. Could we not try to overcome such obstacles and integrate some of the many strands of knowledge, to see what we might see?

This was one of the aims of the 51st annual meeting of the American Institute of Biological Sciences (AIBS) earlier this year. It brought together a group of particularly well-known top biologists, including Stephen Jay Gould, Daniel Janzen, Gene Likens, Lynn Margulis, Gordon Orians, Ghillean Prance, Marvalee Wake, and Edward O. Wilson. Their interests ranged from evolution and biodiversity to developmental biology and behavior, but they all shared unusually broad perspectives. Their plenary lectures were unspecialized; rather, they tried to integrate the findings from the work of many contributing researchers. As well as seeking to show just how far we have come in our understanding of biology in the last century, several speakers tried to draw attention to some of the main challenges our society now faces because of that biology.

AIBS, an umbrella organization for more than 70 separate biology societies, publishes the monthly journal Bioscience. Since 1947, the group has been an important unifying voice for all types of life scientists. This year's annual meeting, cosponsored by the Smithsonian Institution, was a departure from tradition and the first of its kind, with a new, smaller format. It aimed to place some of the unifying principles of biology into a coherent framework with the help of nine eminent plenary speakers who were encouraged to approach their subjects from more than one perspective. Plenary lectures were interspersed with lunchtime poster presentations and open discussions.

Speciation, Biodiversity, and Life's Early Evolution

The meeting's distinguished service award recipient and keynote speaker, Ernst Mayr, now 95, is perhaps best known for his findings on how new species form and adapt to environmental pressures. On reductionism, Mayr quoted from T.H. Huxley's metaphor of "taking water apart," saying that in complex systems, it is not the characterizing of the parts that matters so much, but understanding how they interact, giving rise to "emergent properties." He expressed concern that many scientists today "might become so deeply involved in their specialty that they forget to realize the wider significance of their findings."

Ghillean Prance, former director of the Royal Botanic Gardens, Surrey, England, in a speech on tropical biodiversity and its conservation, emphasized the importance of collections--for example, seed banks and genetic resources--for documenting and understanding the vast store of biological information on Earth, only a small fraction of which we know and even less of which is currently protected. Stephen Jay Gould looked back at three good examples in which biology benefited from the convergence of different disciplines: paleontology-genetics, embryology-genetics, and "evo-devo," or evolutionary developmental biology.

The lecture given by Gene E. Likens, director of the Institute of Ecosystem Studies, New York, and discoverer of acid rain in North America, focused on the "black-box" approach to ecosystem research monitoring. Researchers today can use streamwater nitrate levels, for example, as an indicator of the "health" of forest ecosystems, in broad terms--as, in fact, Likens' team did in a 1970 study at Hubbard Brook, N.H. He emphasized that there are many opportunities for research into complex ecosystem analysis of this kind, but it requires teamwork (which often doesn't come easily to the human species); creative, innovative thinking; and serendipity. Moreover, funding for such studies is difficult to obtain because of their necessarily long-term nature. He cited recent studies that have "only just been published" on the zebra mussel invasion phenomenon in the Hudson River. Just two years after being first spotted, this alien species has multiplied so quickly as to have a dramatic impact on river oxygen and plankton dynamics of the entire river ecosystem. The exact nature and full impact that humans have on the rest of the living world, in global terms, is huge and, worse, hardly known.

Lynn Margulis, one of the original proponents of the endosymbiotic theory for the origin of nucleated cells, followed with a colorful, historical narrative of life on Earth and the "Gaia hypothesis." This concept tries to account for the remarkably stable nature of global atmospheric composition, mean surface temperature, and an alkaline ocean pH that has stayed much the same over millions of years--relatively hospitable conditions that have fostered the evolution and perpetuation of life, in stark contrast to our planetary cousins, Mars and Venus. Margulis then delved into the remarkable diversity of bacteria, focusing particularly on the oxygen-producing stromatolite communities that produced atmospheric oxygen and stabilized sediments. "Those are the ones we have to thank," Margulis said. She also described some of her research, on which she first proposed nearly 30 years ago.

Animal Behavior: Ghosts and Our Evolutionary 'Baggage'

Gordon Orians, professor emeritus at the University of Washington, provided an optimistic but challenging view of the future of investigations in animal behavior. He said that animals are of necessity adapted to previous environments. Our brains, just like other parts of our body, have been molded by evolution, and are "full of ghosts that are models of the past worlds that our species has encountered." This perspective is perhaps best known today as evolutionary psychology. Orians cited a recent Scandinavian study that tested the relative fear elicited by natural stimuli (pictures of snakes) versus culturally conditioned stimuli (handguns) in human volunteers. People reacted much more fearfully to the former than the latter. Such responses may have been adaptive in the Pleistocene, but they are not in today's world. Orians then talked at length about the failure of general-purpose models of learning to account for the full spectrum of animal behaviors. He said that minds are adaptively specialized, each organism facing many cognitive challenges unique to its environment, and thus being selected to evolve different brain structures. Armed with these perspectives, Orians said, researchers interested in animal behavior have dazzling possibilities indeed.

Daniel Janzen, professor of biology at the University of Pennsylvania, talked about the most worthwhile approaches to conservation of tropical forest biodiversity. Drawing from his experiences in Costa Rica at the Area de Conservacion Guanacoste, he said that we must strive to get local people involved at all levels. There is great potential for the marketing of both biodiversity and ecosystem services from conserved wetlands as a way for them to become financially self-sufficient. "We also have to learn to think of a conserved wildland as a garden," he concluded, and he championed Orians' notion that, as a human species, many aspects of our behavior probably haven't changed very much since the Pleistocene.

A Synthesis

Edward O. Wilson, professor at Harvard and well-known entomologist, concentrated on the forging of links between biology and the humanities/social sciences. He admitted that these ideas have been criticized by others as "presumptions and reckless forays." But he added, "There are only two ways to account for the human condition: either by a natural sciences approach, or all the other ways." Offering the example of color vocabularies, Wilson made the point that out of a possible set of 2,036 color combinations, all human cultures have universally chosen just 22. The commonalities of aesthetic judgment--for example, our preferences for certain faces--are also shared across cultures, he said. Human calligraphy styles, though seemingly diverse, also seem to obey certain rules or common patterns. "The theory of arts awaits its Mendeleev," concluded Wilson.

The overriding impression I left with was that ghosts are perhaps the best metaphor for understanding ourselves and our curious habits. As Orians noted, "We have a lot to understand about our own behavior." Much of our behavior, such as war and politics, but also sex, love, and friendship, might mirror the behavior of our hunter-gatherer ancestors if they were still around. Many of these behaviors, or ghosts, evolved for good reasons because they were adaptive. Predispositions toward following them have been wired into our nervous systems and are ultimately encoded in our genomes (though, of course, not without being subjected to environmental influences). But the environment we have constructed for ourselves is very different from the Pleistocene, and the traits we have been given as a species have not all caught up. We hurtle around in small metal boxes on wheels, interact with many people every day in large cities, and spend most of our time indoors with artificial lighting, artificial smells, some of us in front of computer screens much of the time. "We worry more about spiders than atom bombs," as Orians put it.

Patrick Wigge (wiggep@rockvax.rockefeller.edu) is a postdoctoral fellow at Rockefeller University.