Transcript Chapter 10
Chapter 10 Biodiversity Lesson 10.1 What is Biodiversity?? Biodiversity •Short for biological diversity. •The number and variety of different species in a given area. Cataloging •Number of species known to science 1.7 million –Most are insects. •Estimated number of species on Earth 10 million. Attention to Species •Some harder to study. –Receive less attention than larger more familiar species. –Less known about insects and fungi than trees and mammals. 3 Levels of Diversity •Species diversity •Genetic diversity •Ecosystem diversity Species Diversity •All the differences between populations of species as well as different species. Ecosystem Diversity •The variety of habitats, communities, and ecological processes within and between ecosystems. Genetic Diversity •All the different genes contained within all members of a population. Benefits •Stability of the ecosystem (keystone species). •Uses of a variety of species (medicines, foods, etc.) Keystone Species • Species that is critical to the function of an ecosystem. –Hunters kill off otters in an area, sea urchin multiply, kelp (pharmaceuticals, food industry, etc.) goes down. Medical Uses •1/4 of medicines prescribed in the US are derived from plants. •Almost all antibiotics are derived from fungi. Agricultural Uses • Most crops today derived from a few areas of high biodiversity. –Hybrids. –Famines have been caused when disease kills off crops in areas of low biodiversity. Section Review Questions page 244 #1-3. Lesson 10.2 Biodiversity at Risk… Mass Extinction? •Scientists warn of a current mass extinction •Extinc. Increase by 50X since 1800 •Up to 25% of species •Humans primary cause At Risk Species •Those that migrate •Need large or special habitat •Exploited by humans The Road to Extinction •Endangered= likely to become extinct if not protected •Threatened= declining population and likely to become endangered if not protected Human Causes •Destruction of habitat •Introduction of nonnative species •Pollution •Overharvesting Habitat Destruction •Cause of 75% of extinctions now occurring. •Florida Panther p.246 fig 7 • Exotic Species= nonnative species • Poaching= illegal hunting, fishing, harvesting, or trade of wildlife • Pollution- pesticides, cleaning agents, drugs, and other chemicals used by humans make their way into food webs •Endemic Species= native to and found only in a limited area. •The rocky Alpine, Flett’s violet Section Review Questions: page 251 #1-4 Lesson 10.3 The Future of Biodiversity Section review: page 257 #1-4 Saving Species •Captive breeding –Zoos aren’t all bad! •Preserving genetic material •Habitat preservation •Legal protection •International cooperation