Chapter 10: Biodiversity Mr. Manskopf Notes also are at http://www.manskopf.com
Chapter 10 Biodiversity Big Ideas • There is a huge diversity of life on Earth that is critical to all species. . • There are some factors about species that make them prone to extinction. • Human activities are causing large numbers of species to go extinct.
Section 1: What is biodiversity? • How many species live on Earth? • Describe the types of biodiversity. • Explain why biodiversity is important. • Terms: biodiversity, genes, keystone species, ecotourism
About 1.7 million species are known • Estimates vary from greater than 10 million • Why so many unknown?
Biodiversity Which species rule the world?
Biodiversity • Biodiversity: the number of different species in a given area • Tropical rain forests • What factors lead to biodiversity?
Types of Biodiversity Species Biodiversity: number of different species in an area Ecosystem Diversity how many types of habitats in an area Genetic Diversity the number of genes in all members of a population
Ecosystem diversity often leads to species diversity and often genetic diversity
What is a gene? • Gene: a piece of DNA code for a specific trait inherited • Tall, short, brown eyes, etc. Genetic Diversity among corn
Why is genetic diversity important? Cavendish banana “ The fungus Fusarium oxysporum wiped out the previous species of bananas (the Gros Michel) in the 1950s. Now it’s back, having evolved to be able to take on the previously resistant “back-up” species of banana — the Cavendish — that replaced the superior Gros Michel banana after it was wiped out. “
Benefits of Diversity Keystone Species: species that is critical to ecosystem survival • Sea otter • Grey Wolf • Beaver
Keystone Species Food Web Depends Upon Krill
Benefits of Diversity • Genetic Diversity Key To Survival • small isolated populations unlikely to survive • Genetic mutations from inbreeding can occur • More diversity = more likely to survive
Benefits of Diversity • Medical, Industrial, Agricultural uses • Food, cloths, shelter, chemicals and medicine often comes from variety of organisms See table 1 pages 261
Benefits of Biodiversity • Ethics, Aesthetics and Recreation • Moral, religious purposes for all species • Personal enjoyment Dolphin Tour Off NJ Beaches
Benefits of Biodiversity • Ecotourism: tourisms that supports conservation • Wildlife, birding, wilderness hiking • People make $ by having people view wildlife
Section 1 Review • How many species live on Earth? • Describe the types of biodiversity. • Explain why biodiversity is important. • Terms: biodiversity, genes, keystone species, ecotourism
Section 2: Biodiversity at Risk • What does it mean when a species is threatened or endangered? • What makes some species more prone to extinction? • What are the largest threats to biodiversity? • What areas are likely to have high biodiversity? • Terms: endangered species, threatened species, exotic species, endemic species, poaching
Biodiversity has increased over time, but mass extinctions are also natural events (5 major events) How do we get this data?
Extinctions • Species gone forever • NORMAL • Mass Extinction: short period of time when large number of species go extinct (65 MYA) • Currently in mass extinction…caused by humans • Rapid climate change
Extinctions Certain traits make some species more vulnerable: • Small populations • Specialized • Need large range • Migration • Valuable to humans
Current Extinctions • Endangered Species: is likely to go extinct if actions not taken • Threatened: population declining and likely to become endangered
Current Extinctions • TNC estimates 1/3rd of 21,000 identified U.S. animal and plant species are vulnerable. • 30,000 of the world’s species and 1,200 in U.S. are officially endangered.
How do humans cause extinctions? • “HIPPO” • Habitat destruction • Invasive species • Population (humans) growth • Pollution • Overharvesting
Humans Causing Extinctions • Habitat Destruction causes 75% maybe • Large creatures need lot of land • Invasive Species: exotic species not native to area can destroy an ecosystem
Invasive Species CA Agricultural Checkpoints
Humans Causing Extinction • Over-harvesting excessive hunting (bison in U.S.) • Poaching: illegal hunting • Common in poor countries for food, medicines, income • Pollution air, water, land
Areas of Critical Biodiversity • Hotspots: areas threatened that contain high biodiversity • Roughly 25 worldwide • Madagascar • Parts of California
Hotspots Large numbers of endemic species: species native to that area
Areas of Critical Biodiversity • Tropical Rain Forests • Coral Reefs • Coastal Ecosystems • Islands Why these areas????
Section 2 Review • What does it mean when a species is threatened or endangered? • What makes some species more prone to extinction? • What are the largest threats to biodiversity? • What areas are likely to have high biodiversity? • Terms: endangered species, threatened species, exotic species, endemic species, poaching
Section 3: Future of Biodiversity • List and describe efforts to save individual species. • Explain the advantages of protecting entire ecosystems rather than individual species. • Describe the main parts of the Endangered Species Act. • Terms: Endangered Species Act, habitat conservation plans, CITES
Saving Individual Species Captive Breeding Programs: breeding species in captivity with hopes of reintroducing into native habitats Germ Plasm: saving genetic material for possible future use (seeds, eggs, DNA) Zoos and Aquariums
Saving Individual Species • Does little to preserve species • Captive individuals may not survive in wild • Small populations have difficult time with inbreeding, diseases • Last resorts
Preserving Habitat and Ecosystems • Most effective way to save a species is protect its habitat. • Some species require large areas • What about when they leave protected areas? (Wolves in Yellowstone
Legal Protections • Many countries have laws to protect wildlife • Some weak some strong • U.S. law Endangered Species Act (ESA)
ESA Endangered Species Act • Passed 1973 • Protect plant and animals in danger of extinction • List created of those threatened and endangered • Currently 1,272 listed