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Unformatted text preview: D ATE : 1/22/08 ISB N OTES History of life 1. Era ex. year 2. Period smaller break down of an era.ex. month 3. Epoch smaller break down of a periodex. Day First mammals? Mesozoic era First human types? 1.65 million years ago Modern humans? Less than 100,000 years ago Hunters/gatherers? About .01 million years ago Neolific revolution Was the switch from hunting and gathering Dinosaurs died when? Start of Cenozoic era Mass radiations and then mass extinctions What caused these mass extinctions? Global cooling caused most. An asteroid caused the major one at the K-T boundary (dinosaurs) Dinosaurs died, and mammals then flourished b/c of less competition How did these life forms arise? 1. Explanations are difficult Not much hard evidence Most explanations are speculative Sugars and amino acids have been found in rocks from earth, the moon and meteorites from outer...
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This note was uploaded on 03/20/2008 for the course ISB 202 taught by Professor Johnson during the Spring '08 term at Michigan State University.
- Spring '08