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Thurs. 10/24/13

Objective : SWBAT define extinction and identify characteristics that make species vulnerable to extinction. Do Now : What does it mean for something to go extinct? Name as many extinct species as you can. Thurs. 10/24/13. Agenda : Chapter 4 Quiz Species in Danger Life’s Work:

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Thurs. 10/24/13

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  1. Objective: SWBAT define extinction and identify characteristics that make species vulnerable to extinction. Do Now: What does it mean for something to go extinct? Name as many extinct species as you can. Thurs. 10/24/13 Agenda: • Chapter 4 Quiz • Species in Danger Life’s Work: Bring $1 for animal adoption, Read ch. 9 and study for quiz on Tues. Week at a Glance

  2. Extinction: Lights Out • Extinction: complete disappearance of a species from the Earth • Extinction occurs when the population cannot adapt to changing environmental conditions. • Extinctions have existed long before humans had an influence, but the scientific consensus is that human activities are decreasing the earth’s biodiversity. The golden toad of Costa Rica’s Monteverde cloud forest has become extinct because of changes in climate.

  3. Extinction: Lights Out • The current extinction crisis is the first to be caused by a single species - us! • This is happening faster than ever = a few decades instead of thousands to millions of years. • Humans are eliminating not only the species butthe environments as well (ex: tropical rainforests, coral reefs, etc.) The golden toad of Costa Rica’s Monteverde cloud forest has become extinct because of changes in climate.

  4. Species and families experiencing mass extinction Bar width represents relative number of living species Millions of years ago Era Period Some scientists say that we are now in the midst of a 6th mass extinction, caused by humans. Extinction Current extinction crisis caused by human activities. Many species are expected to become extinct within the next 50–100 years. Quaternary Today Cenozoic Tertiary Extinction 65 Cretaceous: up to 80% of ruling reptiles (dinosaurs); many marine species including many foraminiferans and mollusks. Cretaceous Mesozoic Jurassic Extinction Triassic: 35% of animal families, including many reptiles and marine mollusks. 180 According to the fossil record, there have been five major mass extinctions over the past 500 million years. Triassic Extinction Permian: 90% of animal families, including over 95% of marine species; many trees, amphibians, most bryozoans and brachiopods, all trilobites. 250 Permian Carboniferous Extinction 345 Devonian: 30% of animal families, including agnathan and placoderm fishes and many trilobites. Devonian Paleozoic Silurian Ordovician Extinction 500 Ordovician: 50% of animal families, including many trilobites. Cambrian Fig. 4-12, p. 93

  5. Levels of SPECIES EXTINCTION Species is no longer found on the Earth When so few members of a species are left that they no longer play their ecological role Species is no longer found in a particular area

  6. Species in Danger

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