© 2015 Pearson Education, Inc. PowerPoint Lectures Campbell Biology: Concepts & Connections, Eighth Edition REECE TAYLOR SIMON DICKEY HOGAN Chapter 38 Lecture by Edward J. Zalisko Conservation Biology

© 2015 Pearson Education, Inc. Figure Chapter 38: Big Ideas The Loss of Biodiversity

© 2015 Pearson Education, Inc. T HE L OSS OF B IODIVERSITY

© 2015 Pearson Education, Inc Loss of biodiversity includes the loss of ecosystems, species, and genes Biodiversity encompasses three levels: 1.ecosystem diversity, 2.species diversity, and 3.genetic diversity. As natural ecosystems are lost, so are essential services, including the productivity of natural environments for human food supplies and the purification of water used by cities.

© 2015 Pearson Education, Inc Loss of biodiversity includes the loss of ecosystems, species, and genes When ecosystems are lost, the populations that make up their biological communities are also lost. The loss of just one species can negatively affect the species richness of an ecosystem. Extirpation is the loss of a single population of a species. Extinction is the irreversible loss of all populations of a species.

© 2015 Pearson Education, Inc. Figure 38.1b 100% 80% 60% 40% 20% 0% Percentage of species assessed Mammals (N = 4,667) Birds (N = 10,004) Amphibians (N = 4,750) Reptiles (N = 1,882) Total animals (N = 40,307) Data from International Union for Conservation of Nature and Natural Resources (2012). Key Lowest risk of extinction Near threatened Threatened (high risk of extinction) Extinct or extinct in the wild

© 2015 Pearson Education, Inc Loss of biodiversity includes the loss of ecosystems, species, and genes The genetic diversity within and between populations of a species is the raw material that makes an adaptation to the environment possible and a way to protect against future environmental changes.

© 2015 Pearson Education, Inc Loss of biodiversity includes the loss of ecosystems, species, and genes

© 2015 Pearson Education, Inc CONNECTION: Habitat loss, invasive species, overharvesting, pollution, and climate change are major threats to biodiversity Human alteration of habitats poses the single greatest threat to biodiversity. Habitation alteration is caused by agriculture, urban development, forestry, mining, environmental pollution, and deforestation.

© 2015 Pearson Education, Inc CONNECTION: Habitat loss, invasive species, overharvesting, pollution, and climate change are major threats to biodiversity Invasive species rank second behind habitat destruction as a threat to biodiversity. Invasive species compete with native species, prey on native species, and parasitize native species.

© 2015 Pearson Education, Inc CONNECTION: Habitat loss, invasive species, overharvesting, pollution, and climate change are major threats to biodiversity Overexploitation is the third major threat to biodiversity. Overharvesting has threatened rare trees, reduced populations of tigers, Galápagos tortoises, whales, and rhinoceroses, and depleted wild populations of game fish. In parts of Africa, Asia, and South America, wild animals are heavily hunted for food.

© 2015 Pearson Education, Inc CONNECTION: Habitat loss, invasive species, overharvesting, pollution, and climate change are major threats to biodiversity Human activities produce pollutants that may affect ecosystems far from their source. The water cycle transfers pollutants from terrestrial to aquatic ecosystems hundreds of miles away. The release of chemicals into the atmosphere promote the thinning of the ozone layer. Some pollutants contaminate local areas.

© 2015 Pearson Education, Inc CONNECTION: Habitat loss, invasive species, overharvesting, pollution, and climate change are major threats to biodiversity Biological magnification concentrates industrial wastes and pesticides as they pass through the food chain. Top-level predators are usually the organisms most severely damaged by toxic compounds in the environment.