PPT-Did Humans Cause the Glacial Extinctions?

By Alex Bauman Do you think that humans are the sole reason for the extinctions Scientists Continue to Disagree Changes in habitat Hunting by humans Combination of both reasons Woolly Mammoths. Mass extinctions are global events characterized by unusually high rates of extinction The magnitude of these rates is usu ally unspecified but it is generally significantly higher than the rate of so called background extinctions that is extinc tio The struggle for life on earth. Mass Extinction - Definition. A significant proportion of species become extinct (between 30% and 95%) . The extinctions operate across a wide range of environments and . Overview. Extinctions are as important in the history of life as are the evolution of new species. Explaining extinctions is just as challenging a scientific question as explaining the evolution of new species. The sixth . m. ass . e. xtinction. Objectives. Define . extinction.. Give examples of (1) past mass extinctions (2) and recent species . extinctions.. Compare current extinction rates with background extinction . Document Name: THE GLACIAL HIST. & DEV. OF MI Requestor’s ID: Author’s Name: Alice Wilson Document Comments: Jennifer Daniels - Manuscript by S.G. Bergquist [P. 6A At end of document] 1) Geological Time Scale. 2) Major Episodes in History of Life. 3) Extinctions and Radiations. Today. ’. s OUTLINE:. Geology plays an Important role in Evolutionary Thinking. Patterns of extinctions and evolutionary change in the fossil record were among the main influences on. Unit 5: Gradational Processes. Ms. . Thind. Glaciers. 10% of land is covered with glacial ice.. Store 75% of the world’s freshwater. . If all land ice melted, sea level would rise approx. 70m . Glaciers: importance?. Ch 15: p 277-281. Glaciers:. Enormous masses of moving ice created by the accumulation and compaction of snow.. Powerful agents of erosion ~ have carved some of the most spectacular features on Earth’s surface. What is extinction? . Extinctions occur when the last individual of a species dies out. . Functional Extinctions occur when individuals remain but the odds of sustainable reproduction are low. i.e. the species is effectively extinct even though individuals remain. . Definition. Used with permission from Microsoft. 20,000 years ago. ~3 km thick. Crust deformation. Mantle flows away. The ice. Used with permission from Microsoft. Glaciers retreated. Slow uplift. Mantle returned. B. Landforms : an accumulation of till deposited by direct glacial action. Ground moraines are relatively level to gently rolling and are formed by the deposition of accumulated material beneath the Once . glacial ice exceeds a thickness of about 150 feet, the weight of the overlying ice causes . the . base of . the glacier . to become plastic and flow like a very viscous liquid. While the bottom ice responds as a plastic solid, the surface ice is very brittle. However, from the surface down to the top of the plastic portion of the glacier, the ice experiences a decrease in . GEO101. Spring 2023. Contents. Growth of glaciers in the Cenozoic Era. Glacial cycles. The astronomical theory for glacial cycles. Cenozoic Glaciers. Cenozoic era started cooling 50 million years ago.. Extinction . When an organism is classed as extinct there are no living members of that species left. Extinction is a natural process where organisms that are less suited to an environment die out. Throughout the history of earth there have been several mass extinction events .