CHAPTER 38 Conservation Biology

1. CHAPTER 38Conservation Biology Modules 38.1 – 38.3

2. Saving the Key Deer • Modern human culture and the rapidly growing global human population have created a biodiversity crisis • There is a rapid decrease in the variety of species on Earth • The decline in Key deer populations is an example of this crisis • The Key deer is a miniature subspecies of the whitetail deer found only in the Florida Keys

3. The National Key Deer Pine Refuge was established on Big Pine Key island in 1957 • The deer population rebounded to 600-800 • The Key deer is still on the endangered species list • The Key deer was nearly exterminated by hunting in the early 1900s

4. Development has reduced the Key deer habitat • Motorists have become the main threat to the deer's survival • The human population on Big Pine Key has increased tenfold since 1967

5. Conservation biology relies on research from all levels of ecology, from populations to ecosystems • Conservation biology is a goal-oriented science that seeks to counter the biodiversity crisis

6. THE BIODIVERSITY CRISIS: AN OVERVIEW 38.1 Habitat destruction, introduced species, and overexploitation are the major threats to biodiversity • Human alteration of habitats poses the single greatest threat to biodiversity • The loss of tropical rain forests and marine habitats are especially devastating Figure 38.1A

7. Introduced species are those that have been transferred to an area where they did not occur naturally • Examples: European starlings, pigeons, and house sparrows • Competition with introduced species also threatens many species in their native habitats

8. 200 species of freshwater fish were lost due to the introduction of the Nile perch • One of the largest rapid-extinction events ever recorded occurred in Lake Victoria, East Africa Figure 38.1B

9. Excessive commercial harvest or sport hunting has reduced the numbers of many species • Examples: whales, American bison, Galápagos tortoises, and numerous fish • Overexploitation of wildlife also threatens many species

10. 38.2 Biodiversity is vital to human welfare • Preservation of biodiversity is important to humans for aesthetic, ethical and practical reasons • Biodiversity provides humans with food, clothing, shelter, oxygen, soil fertility, etc. • We evolved in Earth's ecosystem • Large-scale changes in the ecosystem threaten us as well as other species

11. Medicinal plants and their derivatives play an important role in the pharmaceutical industry • The rosy periwinkle of Madagascar provides two substances effective in the treatment of Hodgkin’s disease Figure 38.2

12. 38.3 Connection: Technology and the population explosion compound our impact on habitats and other species • The explosive growth of the human population and of technology continues today • Although the populations of developing nations are growing the fastest, it is the resource consumption of the less populous, developed nations that puts a greater strain on the biosphere

13. Table 38.3

14. Oil spills, acid rain, ozone depletion, and chemical pesticides affect the entire world Figure 38.3a

15. DDT concentration:increase of10 million times DDT infish-eating birds25 ppm • Chemical pesticides are concentrated in food chains by biological magnification DDT inlarge fish2 ppm DDT insmall fish0.5 ppm DDT inzooplankton0.04 ppm DDT in water0.000003 ppm Figure 38.3B