BIOLOGY CONCEPTS & CONNECTIONS Fourth Edition Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Neil A. Campbell Jane B. Reece Lawrence G. Mitchell Martha R. Taylor From PowerPoint ® Lectures for Biology: Concepts & Connections CHAPTER 38 Conservation Biology Modules 38.1 – 38.3

Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings 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 Saving the Key Deer

Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings The Key deer was nearly exterminated by hunting in the early 1900s The National Key Deer Pine Refuge was established on Big Pine Key island in 1957 –The deer population rebounded to The Key deer is still on the endangered species list

Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings The human population on Big Pine Key has increased tenfold since 1967 –Development has reduced the Key deer habitat –Motorists have become the main threat to the deer's survival

Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Conservation biology is a goal-oriented science that seeks to counter the biodiversity crisis Conservation biology relies on research from all levels of ecology, from populations to ecosystems

Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Human alteration of habitats poses the single greatest threat to biodiversity –The loss of tropical rain forests and marine habitats are especially devastating 38.1 Habitat destruction, introduced species, and overexploitation are the major threats to biodiversity THE BIODIVERSITY CRISIS: AN OVERVIEW Figure 38.1A

Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Competition with introduced species also threatens many species in their native habitats –Introduced species are those that have been transferred to an area where they did not occur naturally –Examples: European starlings, pigeons, and house sparrows

Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings One of the largest rapid-extinction events ever recorded occurred in Lake Victoria, East Africa –200 species of freshwater fish were lost due to the introduction of the Nile perch Figure 38.1B

Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Overexploitation of wildlife also threatens many species –Excessive commercial harvest or sport hunting has reduced the numbers of many species –Examples: whales, American bison, Galápagos tortoises, and numerous fish

Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings 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 38.2 Biodiversity is vital to human welfare

Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings 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

Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings 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 38.3 Connection: Technology and the population explosion compound our impact on habitats and other species

Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Table 38.3

Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Oil spills, acid rain, ozone depletion, and chemical pesticides affect the entire world Figure 38.3a

Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Chemical pesticides are concentrated in food chains by biological magnification Figure 38.3B DDT in water ppm DDT in zooplankton 0.04 ppm DDT in small fish 0.5 ppm DDT in large fish 2 ppm DDT in fish-eating birds 25 ppm DDT concentration: increase of 10 million times