Rowan Video Guide Video Guide: Extinction! (Part 1) 1. _____to_____% of all species that have lived on this planet have become extinct. 2. On the average, a species dies out after _____ million years on earth. 3. How does a "house of cards" compare to the interactions of species in an ecosystem? 4. _____% of species present during the Permian survived into the Triassic. 5. Expeditions into the Gobi desert have revealed fossils of early _______________ that lived during the same time as the dinosaurs. 6. It is thought that an asteroid collision caused the extinction of the dinosaurs __________million years ago, but the __________survived! 7. Why did mammals thrive after the K-T event? 8. When and where did the first human-like primates emerge? 9. Today, the rate of extinction is ________ times greater than it has ever been. 10. What do scientists think will cause, or is causing, the 6th great extinction on Earth? Explain. 11. Abundant sign of large _________________ indicates a relatively healthy ecosystem. Rowan Video Guide Video Guide: Extinction! (Part 2) 12. One hundred pounds of ________________ will sustain _______ pounds of herbivores. Ten pounds of herbivore will sustain ________ pounds of carnivore. 13. What is the #1 cause of extinction today? 14. What is the #2 cause of extinction today? 15. What is the ratio of native species to invasive species in the Hawaiian Islands today? 16. What is an invasive (a.k.a. “weed”) species? Why are they so harmful? 17. Describe the problems associated with "leafy spurge" in North Dakota: 18. How are we combating "leafy spurge"? 19. What is "our greatest tool" against extinction?