Transcript SAES CH9x
CHAPTER 9 BIODIVERSITY Will the bark of an ordinary tree in Samoa become a cure for cancer? NATURE’S MEDICINE CABINET Do Now • Why is biodiversity important? Be specific. • What do we “get” from nature? Be specific What We Get From Nature Nature’s Medical Cabinet • Medicinal plants provide health care and income to local communities • Medicinal plants worth $100 billion in 2011 • 50% of all prescription drugs originally derived from plants (e.g.; aspirin) • How many more are left to be discovered? Ethnobotany The study of how different cultures use the plants in their local environment “Mother Nature is the ultimate chemist.” Mamala tree leaves relieve symptoms of Hepatitis C Biodiversity A measure of all of the plant, animal & microbial species in an area or on Earth How many species are there? We don’t really know! 1.8 million species are known, but there could be ~100 million still to be discovered. Earth’s Natural Citizens WHAT IS NATURE WORTH? What would it cost to buy all of the ecosystem services we get for free from nature? minerals oxygen fossil fuels climate control water Approximately $33,000,000,000,000 erosion control recreation (parks, etc.) medicine biodiversity 80% of Samoa’s tropical oasis of biodiversity and medical cures has been lost due to deforestation. Endemism Plants and animal species that exist only at one location on Earth Biodiversity Hotspots Regions that contain large numbers of endemic and threatened species. Biodiversity Hotspots Extirpation • When a species is extinct in one region but still present elsewhere • Reintroduction to the extinct region is possible. Taxonomic Distribution of Endangered Species Endangered Species Act The 1973 law protecting biodiversity in the United States How to Conserve Biodiversity Single Species Approach • Focus is on well-known, charismatic species • Pandas, eagles, gray wolves • Has led to successful captive breeding programs • But, what about all the other species that need saving? Ecosystem Approach • Focus is much broader target – entire ecosystems • Preserves all of the species and their interactions • Emphasis often on biodiversity hotspots How to Conserve Biodiversity Debt-For-Nature Swap Developing nation’s foreign debt paid by preserving its natural areas Remember the Mamala tree? • Also produces prostratin • Effective in treating HIV • Has led to successful captive breeding programs • US firms attempting to produce synthetic version • Profit-sharing agreement: • Local Samoans receive 50% of all royalties from sale of prostatin “There is a strong link between the health of forests and the health of humans. If people understand that a rainforest might contain the best cures for diseases that plague us, they will care a whole lot more about saving it.” -Paul Cox What do these two chemicals have in common? Paclitaxel Docetaxel Pacific Yew Tree