ENV100Y5 Chapter Notes - Chapter 4: Divergent Evolution, Convergent Evolution, Evolutionary Pressure
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ENV100Y5 Full Course Notes
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Document Summary
Chapter 4 evolution, biodiversity and population ecology. 1 (91) evolution as the wellspring of earth"s biodiversity. Biological evolution - results from random genetic changes, may proceed naturally or by natural selection. Natural selection - process where traits that enhance survival reproduction are passed on more frequently to future generations that those that don"t. Darwin and wallace - organisms face a struggle to gain resources to survive and reproduce. They produce more offspring than can possibly survive. Individuals of the same species vary in their characteristics - due to genes, env within the genes are expressed, interaction between genes and env. Most of planet"s rich biodiversity = tropical rainforests. Adaptive trait or adaption = success vs. maladaptive = reduce success. Process of recombination produces novel combinations of genes, generating variation among individuals. Directional selection - selection that drives a feature in one direction rather than the other. Stabilizing selection - produces intermediate trait, preserving status quo.
