RTW: Page 214-17

1. RTW: Page 214-17 Explain one approach conservation biologists use to protect biodiversity.

2. RTW Tuesday, January 28th Fill in the diagram with terms from the word bank to show how thesethree levels of biodiversity are related • ecosystem diversity genetic diversity species diversity A. _____ B. _____ C. _____

3. Extinctions: The End of Biodiversity

4. What is extinction? • Extinctions occur when the last individual of a species on earth dies out. • Extirpation occurs when a population dies out in a particular area, but not globally. • For example, the timber wolf was until recently extinct in Wisconsin but not in Minnesota

5. When do extinctions occur? • Extinctions occur when the environment of a species changes faster than the species can adapt. • In other words, a species’ adaptations are no longer sufficient in allowing that species to acquire and compete for resources.

6. Extinctions are natural. • Background Extinctions: Naturally occurring extinctions, occurring one species at a time • Nearly all of the species that have existed on earth have gone extinct. • Mass Extinctions (5): Events when extinction rates far exceed the normal background rate • There have been 5 major mass extinctions in geological history. • Recovery from these events took millions of years.

7. Mass Extinction Diagram Source: http://www.uwec.edu/jolhm/EH4/Extinction/Extinction.ppt

8. Mass Extinctions • Cretaceous-Tertiary Extinction (65 mya). • End Triassic Extinction (200). • Permian Triassic Extinction (250). • Late Devonian Extinction (364). • Ordovician-Silurian Extinction (440). (#= millions of years ago) Source: http://www.uwec.edu/jolhm/EH4/Extinction/Extinction.ppt

9. Estimate! How does the current rate of extinction compare to the background rate of extinction? For example: I believe the current rate of extinction is ____x greater than the usual background rate of extinction.

10. The Holocene Extinction?? • Catastrophic extinctions, as was the case when an asteroid-strike wiped out the dinosaurs, actually took many thousands of years to occur. • The current extinction rate appears significantly greater. • In other words, human-activity is killing off species faster than an asteroid could 65 million years ago. • Source: United States Committee on Scientific Issues in the Endangered Species Act, National Research Council. Science and the Endangered Species Act. National Academy Press, Washington D.C. 1995

11. Current Stats • The current rate of extinction is 1500times greater than the usual background extinction rate. • BjørnLomborg, The Skeptical Environmentalist: Measuring the Real State of the World, Cambridge U. Press, Cambridge, 2001. • 90% of all large fish have disappeared in the last 50 years due to over-fishing. • Myers, Ransom. Worm, Boris. Biology Department, Dalhousie University, Halifax, Nova Scotia, Canada, Rapid Worldwide Depletion of Predatory Fish Communities. Nature. Volume 423. P. 280. May 2003 • The Audubon Society reports that 30% of North American songbird species are in significant decline. • One in eight plant species are in danger of extinction within the next 30 years (ICUN Red List) • “Half of bird and mammal species will be gone in 200 to 300 years” • Levin, Phillip and Levin, Donald. The Real Biodiversity Crisis. January, 2002. American Scientist, Volume 90, Number 1, Page 6 • One species is going extinct every 20 minutes. • Levin, Phillip and Levin, Donald. The Real Biodiversity Crisis. January, 2002. American Scientist, Volume 90, Number 1, Page 6

12. Modern Causes of Extinctions • Major current causes of extinctions include: • Habitat Loss: leading cause • Invasive Species: second leading cause • Over-harvesting • Pollution

13. Habitat Loss • Organisms, adapted to their habitat, decline in population when the habitat changes. • Habitat fragmentation: Patches of suitable habitat surrounded by unsuitable habitat • In general, larger habitat fragments can support greater biodiversity than smaller fragments. Did You Know?Habitat change or destruction is the primary cause of population decline in more than 80% of threatened birds and mammals.

14. Invasive Species • Invasive species can out-compete and displace native species. • An introduced species will likely become invasive if the area lacks limiting factors: • Predators • Parasites • Competition

15. Overharvesting • Humans hunt, fish, or harvest a species faster than it can replenish its population. • Examples include: • Tigers • Rhinos • Sharks • Fish

16. Climate Change • Unlike the other factors, climate change will have a potentially global effect on biodiversity. Did You Know?Scientists predict that a 1.5–2.5C global temperature increase could put 20–30% of plant and animal species at increased risk of extinction. • Shaving • Planes

17. Case Study • Corn is a key crop in America • Makes up a large portion of our food supply • Dairy cows eat it to make milk • Hens eat it to lay eggs • Cattle, hogs, and chickens eat it to fatten up before slaughter • Its used to make high fructose corn syrup (sweetener in soda, popsicles, creamer, etc) • Corn oil is used to fry foods • It is the building block of ethanol, a major component of car fuel

18. Case Study • The US corn crop has been nearly wiped out by a leaf fungus. The government has hired you to develop a plan to recover the crop. • Write down your ideas on how to save the corn crop

19. Biodiversity & Crops • During the 1970s the U.S. corn crop was almost completely wiped out by a leaf fungus. • The corn crop was saved by interbreeding it with a rare species of wild corn from Mexico. • Genetic engineering may also offer some hope by facilitating transfer of genes between species. • This increases the value of wild strains which can be used as sources for new traits to be introduced into crops. • http://www.emc.maricopa.edu/faculty/farabee/biobk/biobookcycles.html

20. Biodiversity & Agriculture • There are almost 80,000 species of edible plants • Fewer than 20 produce 90 percent of the world’s food. • 4 crops (wheat, corn, rice, soybeans) provide most of the world’s food. • If underutilized species are conserved, they could help to feed growing populations. • http://www.fws.gov/endangered/esa-library/pdf/Why_Save_Endangered_Species_Brochure.pdf

21. Biodiversity & Medicine • More than a quarter of all prescriptions written annually in the United States contain chemicals discovered in plants and animals. • A few hundred wild species have stocked our pharmacies with antibiotics, anti-cancer agents, pain killers, and blood thinners. • We have only discovered 10-20% of living species so far! • http://www.fws.gov/endangered/esa-library/pdf/Why_Save_Endangered_Species_Brochure.pdf

22. Biodiversity & Ecosystem Services • Ecosystem services include air and water purification, detoxification and decomposition of wastes, climate regulation, regeneration of soil fertility, and the production and maintenance of biological diversity. • These are the key ingredients of our agricultural, pharmaceutical, and industrial enterprises. • Such services are estimated to be worth trillions of dollars annually. • We get these services for free…for now. • http://www.fws.gov/endangered/esa-library/pdf/Why_Save_Endangered_Species_Brochure.pdf

23. Notebook Check! • Vocabulary pg 220 (word wall) • Natural selection, biodiversity, and extinction notes • Natural Selection iPad activity (5 species) • Cloning Questions