Consider the following… • Everyday, somewhere on Earth, a species becomes extinct. • Often this is because of human actions. • How much extinction is natural? • Can we, or even should we, prevent extinctions?
Biodiversity • Short for biological diversity • Refers to the number and variety of different species in a given area.
Numbers of Species Named • 1.7 million known species, most insects. • Vertebrates account for only 50,000. • Scientists estimate there are more than 10 million species.
Levels of Diversity • Species diversity: differences between populations of species. • Ecosystem diversity: refers to the variety of habitats. • Genetic diversity: refers to all the different genes contained within members of a population.
Benefits of Biodiversity • Species are connected to ecosystems: -each species plays a part in an ecosystem. -every species depends and is dependent on at least one other species. -keystone species: critical species to an ecosystem. Example: sea otters
Benefits of Biodiversity 2. Species and population survival: -as populations shrink, genetic variation decreases. -leads to inbreeding, inheritance of genetic diseases -bottlenecking: describes populations shrinking and decreasing genetic variations.
Benefits of Biodiversity 3. Medical, Industrial, and Agricultural Uses: -food, clothing, shelter, and medicine -Examples: -Taxol, cancer drug, pacific yew -Novacain, anesthetic, coca plant
Benefits of Biodiversity 4. Ethics, Aesthetics, Recreation -cultural and religious reasons -ecotourism: form of tourism that supports the conservation and sustainability of an ecosystem.
Biodiversity at Risk: Mass Extinctions • Mass extinctions: the extinction of many species in a short amount of time. • Example the dinosaurs 6.5 mya
Current Extinctions • We are in the midst if another mass extinction scientist warn. • Rate of extinction up by a multiple of 50 since 1800’s.
Species Prone to Extinction • Those that migrate, need large spaces, special habitats, or exploited by humans.
Endangered Species • Species that is likely to become extinct if protective measures are not taken.
Threatened Species • A species that has a declining population and is likely to become endangered if not protected.
How Do People Cause Extinction? • Habitat Destruction and Fragmentation: • Building homes, harvesting resources. • 75% of extinctions due to habitat destruction. • Example: Florida Panther
How Do People Cause Extinction? • Invasive Exotic Species: a species that is not native to a particular region. • Threaten native species.
How Do People Cause Extinction? • Harvesting, Hunting, and Poaching • Overuse • Examples: Passenger Pigeon, bison, elephants, rhinos
How Do People Cause Extinction? • Pollution: pesticide, cleaning agents, drugs, and other chemicals are making way into food web. • Example: DDT
Endemic Species • species found only in a limited area and nowhere else.
Areas of Critical Biodiversity • Tropical Rain Forest • Coral Reefs and Coastal Ecosystems • Islands
Biodiversity Hotspots • The most threatened areas on Earth • 25 named • Examples: Madagascar, Mediterranean Basin, Western Ecuador, California Floristic Province.
The Future of Biodiversity • Saving one species at a time by: • Captive Breeding Programs • Preserving Genetic Material • Zoos, aquariums, parks, and gardens
The Future of Biodiversity • Preserving habitats and ecosystems
The Future of Biodiversity • Legal protection for species: • US laws: Endangered Species Act • Recovery and Habitat Conservation Plans: cooperative agreements to protect large areas of land
The Future of Biodiversity • International Cooperation: • International Trade and Poaching: CITES (Convention on international trade in endangered species) • The Biodiversity Treaty: goal is to preserve biodiversity and ensure that sustainable and fair use of genetic material for all countries.
The Future of Biodiversity • Private Conservation Efforts: • World Wildlife Fund