Eighty percent of the 150 top selling drugs in the United States--including essential medicines such as Asprin, penicillin, and the chemotherapy drug Taxol--come from substances derived from plants, animals or microorganisms. However, as humans continue to drive species towards extinction and degrade critical habitats, we are losing the life-giving services they provide and the potential for countless new medical discoveries. A new book, "Sustaining Life," examines what humans stand to lose when biodiversity is irreversibly destroyed, providing a compelling new case to conserve nature.
The "Sixth Great Extinction Event"
The current rate of species extinction is hundreds to even thousands times greater than historical background levels, leading many biologists to conclude that we have entered the "sixth great extinction event" in Earth's history (the fifth occurred 65 million years ago when the dinosaurs disappeared). This stunning loss of biodiversity is a result of habitat loss, destruction and degradation of ecosystems, pollution, over-exploitation and climate change, among other human drivers.
Recent research has highlighted the worldwide decline of vital ecosystem services, provided for free by nature, which are estimated to have a global economic value of $33 trillion per year. These include water regulation and supply, flood and storm protection, nutrient cycling, recreation, and countless others. "Sustaining Life" focuses on just one benefit of nature: new avenues of medial research, treatments and pharmaceuticals.
A Potential New Medical Treatement Lost
Let us consider one example highlighted by the book's authors:
The southern gastric brooding frog was discovered in the undisturbed rainforests of Australia in the 1980s. The females of this unique species do something found nowhere else in nature: they raise their young in their stomachs. This bizarre upbringing is only possible because the baby frogs produce a substance that inhibits acid and enzyme secretions, thus preventing them from being digested. Scientists immediately recognized that research on these frogs could lead to new insights into preventing and treating human peptic ulcers, which affect at least 25 million people in the U.S. alone.
Before researchers could make any medical discoveries, however, the southern gastric brooding frog went extinct. In fact, nearly one-third of the approximately 6,000 known amphibian species (frogs, toads, news, slamanders) are threatened with extinction.
"Sustaining Life" called on the expertise of over 100 scientists from around the world to explore seven threatened groups of organisms valuable to medicine: amphibians, bears, cone snails, sharks, nonhuman primates, gymnosperms, and horseshoe crabs. According to co-author Jeffrey McNeely, it "offers dozens of dramatic examples of both why and how citizens can act in ways that will conserve, rather than destroy, the species that enrich our lives."
Species Threatened with Extinction
as a Percent of Total Number of Known Species
Source: IUCN Red List, 2008
RELATED LINKS:
Harvard Medical School Center for Health and the Global Environment
IUCN Red List of Threatened Species
Convention on Biological Diversity
EarthTrends
Biodiversity data and statistics
