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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.
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| 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 | |
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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.
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| 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 |
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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
Office of University Relations