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roundtable:a modern mass extinction Watch Show 3:
"Extinction!" on PBS
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First, a general question. Are we now in a mass extinction, and if so, why does it matter?
Some Web visitors wrote to say they have heard it said, especially of tropical and marine organisms, that we are losing species before we even know of them. And the question is, if we haven't discovered a species yet, how do we know that we've lost it?
Would Darwin support the Federal Endangered Species Act? Millions of dollars are spent by corporations and government for habitat conservation plans, recovery plans, etc., for species that seem doomed for extinction. Is this a wise use of money? Why or why not?
If extinction and mass extinctions are a natural part of Earth's history, should we really be concerned about our effects on endangered species? Are we trying to fight something that's inevitable anyway and that is much larger than us, as a single species ourselves?
I'm concerned with the loss of genetic diversity because it affects food supply, drug discoveries, and the stability of ecosystems on which we depend. And yet, I'm very skeptical of the theory of evolution as it now stands. How does the theory of evolution -- or we could also say that as evolutionary thought -- explain and predict what's going on with the current cycle of extinction, better than if we had to just rely on what we can observe? In other words, what context and what value does evolutionary thought provide to this discussion that we're having?
Several other questions relate to this: Loss of biodiversity, water and air pollution, and the greenhouse effect are all impacting the biosphere, and if these are indeed combining to produce a mass extinction, do you think our species will survive it? Peter's already said that he thinks yes. How about some other perspectives?
Let's move onto some more specific questions. Why do bigger species go extinct faster than smaller ones?
Do you feel that extinctions of large Ice Age mammals had any human causes?
Another Web user wrote: I know there is a gene databank under construction right now. Could this be used as a modern Noah's Ark for the future?
We'll wrap up with a different kind of question. There was one that came from a younger visitor to the Web site who asked, What can kids do to help save the rain forest and animals?
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 Panelist Bios
Tundi Agardy (a woman) Tundi Agardy is an internationally renowned expert on marine conservation, specializing in marine protected areas and coastal planning. From 1997 to early 2001, she was senior director for the Global Marine Program at Conservation International, a global environmental organization.
Ariel E. Lugo (a man) Ariel E. Lugo is director of the USDA Forest Service International Institute of Tropical Forestry in Río Piedras, Puerto Rico. An ecologist, his research has focused on tropical ecosystems, particularly rain and dry forests and forested wetlands.
Daniel Simberloff Daniel Simberloff is professor of environmental studies and director of the Institute for Biological Invasions at the University of Tennessee. He has conducted extensive research on the rates and causes of species extinction, on the nature of ecological communities, and on the impacts and management of introduced species (those who migrate to a new area).
Peter Ward Peter Ward is professor of geological sciences at the University of Washington in Seattle, where he is also adjunct professor of zoology and of astronomy. He is the author of nine books on biodiversity and the fossil record, and is the principal investigator for the University of Washington's portion of the NASA Astrobiology Institute.
 Moderator Bio
Joe Levine Joe Levine, science editor for the Evolution project, earned his Ph.D. at Harvard University, where he studied the physiology and evolution of color vision. With Ken Miller, he has written widely acclaimed biology textbooks for high school and college. Since 1987, he has served as advisor to the Science Unit at WGBH, working on NOVA programs and numerous special projects.
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