BI SC 002 Lecture Notes - Lecture 29: Supercontinent, Mantle Convection, Cervus
31 Oct 2016
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Document Summary
Random, favorable changes are selected for over time by nature in a consistent, non-random way. Any change in heritable traits within a population across generations. Clues to evolution lie in the earth, body structures, and molecules. Life on earth arose 3. 8 billion years ago. Changes in body structures and molecules have slowly accumulated through that time: producing the variety of organisms we see today. Scientists use the geologic timescale to divide the history of the earth into eons and eras. These periods are defined by major: geological events, biological events. The most historical events at the base. Earth"s geography has changed drastically over the last 200 million years. According to the theory of plate tectonics: earth"s surface consists of several rigid layers. Move in response to forces acting deep within the planet. Modern version of continental drift : alfred wegener. Explains the features and movement of the earth"s surface: past, present.
