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WWeek of 14 February 2003· Vol. VI, No. 21

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SED biologist galvanizing new field of symbiology

By Tim Stoddard

For Douglas Zook, the unsung heroes of the natural world are tiny and cooperative. They are the microscopic organisms that shack up in symbiotic living arrangements, such as the fungi and algae that form lichens and the aphids and ants that live in cooperative colonies. Zook sees these symbiotic relationships everywhere in nature, from deep-sea hydrothermal vents to cow stomachs to rice paddies. But his passion for all things symbiotic is tempered by a concern that educators and researchers have given symbiosis short shrift for too long.

This sea anemone in a tidal pool in Santa Cruz, Calif., gets its green color from symbiotic algae living within its tissues. Photo by Douglas Zook
  This sea anemone in a tidal pool in Santa Cruz, Calif., gets its green color from symbiotic algae living within its tissues. Photo by Douglas Zook

Zook, an SED associate professor of science education and biology, is leading an international effort to bring together botanists, zoologists, and ecologists who study diverse examples of symbiosis and provide a forum for them to communicate about their interests. As president of the International Symbiosis Society (ISS), he is organizing the fourth annual ISS Congress from August 17 to 23 at Saint Mary’s University in Halifax, Nova Scotia. It will be a venue for scientists and high school teachers to present research and discuss strategies for incorporating symbiosis into precollege curricula.

“A botanist looking at fungal-plant relationships wouldn’t normally think about speaking with a coral researcher,” Zook says. “The congress is a chance to bring together these biologists from different subfields, and from that can come new understandings, new ways of looking at the planet.”

Some of those earlier insights have led to paradigm shifts in biology. “We’re beginning to think that symbiosis plays a key role in a lot of the evolutionary novelty in nature,” Zook says. While evolution was once thought to be a gradual process of accumulated changes, he says, biologists now believe “that new, sudden changes may come about through symbiotic events -- one living thing taking over another one.” It’s now well-accepted that mitochondria, the powerhouses in cells that convert sugars into energy, were free-living bacteria about two billion years ago. They were engulfed by a larger single-celled organism, and the two somehow managed to coexist. Chloroplasts, which are the photosynthesizing components within plant cells, were also probably once free-living cyanobacteria, or algae.

Symbiology traces its origins to around the turn of the 19th century, when Russian scientists began studying lichens in greater detail. But Zook says that symbiosis was largely ignored because biologists at the time didn’t think that cooperation was realistic in the Darwinian world of competition and survival of the fittest. “People thought it was soft science to have things cooperating,” he says. “But there comes a point where certain individuals find that it’s more optimal to give up the fierce fight and share their resources within a cell or a structure or a habitat.”

Threats to symbionts
This year’s congress features a panel of luminaries in symbiology, such as Lynn Margulis, a former BU biology professor, who is a modern pioneer in the study of symbiosis. The theme of the conference is global threats to symbionts, organisms living in symbiosis, with a focus on the fate of coral reefs. Corals are really two creatures in one. Every coral polyp in a colony harbors an alga within its cells that photosynthesizes and feeds the coral with sugars and nutrients. In return, the coral protects the alga with stinging cells and feeds it with the waste products of its own respiration. But since the 1980s, scientists have noted the alarming spread of coral bleaching in reefs around the world. It’s now widely believed that rising water temperatures kill the algae inside corals, and without its partner, the coral animal starves and leaves behind a white skeleton. Ove Hoegh-Guldberg, a leading expert on coral bleaching from the University of Queensland in Australia, will present an overview on this topic along with recent findings.

Douglas Zook is passionate about all things symbiotic. The orchid to his left is an example of a symbiotic plant that depends upon another organism to provide it with essential nutrients. Photo by Vernon Doucette


Douglas Zook is passionate about all things symbiotic. The orchid to his left is an example of a symbiotic plant that depends upon another organism to provide it with essential nutrients. Photo by Vernon Doucette


Coral bleaching is just one example, Zook says, of how humans need to understand the nature of symbiosis. Fishing industries, and the economies of many nations, depend on the long-term health of coral reefs, he says, and it’s in understanding the delicate relationship between coral and alga that scientists may be able to reverse the bleaching that threaten reefs worldwide.

Along with promoting collaborations between researchers, the ISS is also working to integrate symbiology in education, and one of the sessions at the congress will bring together high school teachers and researchers to discuss ways of doing this. “What’s exciting about that is that the scientists who are working on cutting-edge research will be in the workshop interacting with teachers,” Zook says. “We did this a little bit at a previous congress and it worked beautifully, so we’re going to expand upon it now.”

Zook (COM’75, MET’78) is widely recognized for his contributions to teaching methods in biology. After he joined the BU faculty in 1987, he and Margulis, who now teaches at UMass-Amherst, launched the Microcosmos Project, a curriculum and teacher-workshop program that emphasizes the study of microscopic life-forms through innovative art projects and simple experiments. Symbiosis is a prevalent theme in Microcosmos, Zook says, because virtually every known case of symbiosis involves at least one microorganism. And while over 8,500 teachers in several countries have participated in Microcosmos, “symbiosis still has a long way to go,” he says, “before it fully enters high school curricula.”

To help integrate symbiosis lessons in high schools, the ISS has recently produced a set of 60 slides depicting a wide range of symbiotic relationships. The slide set is available for purchase on the ISS Web site (www.ma.psu.edu/~lkh1/iss/), and in the coming months, the society will be developing PowerPoint presentations that teachers will also be able to use.

Zook is passionate about getting people interested in symbiology because he is genuinely fascinated by the myriad examples of symbiosis in nature. But apart from the drive to enlighten students about a neglected area of science, he also believes that symbiotic creatures can be role models for Homo sapiens. “If symbiosis is important to making forests and reefs, then it would behoove us to know as much about it as possible so that we can be better partners ourselves with the earth,” he says. “Our future as human beings depends upon our symbiosis with the planet and its systems.”

For more information on the fourth International Symbiosis Society Congress, visit people.bu.edu/dzook.


14 February 2003
Boston University
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