BIOL 1001 Lecture Notes - Lecture 18: Macroevolution, Genetic Drift
Document Summary
Macroevolution patterns, origins, diversification etc. over long periods of evolutionary history. Sudden evolution and long periods of stasis. If it"s gradual: see transitional forms over a long period of time in fossil records, ex. Transitional evolution of whales (land mammals to aquatic mammals) If it"s burst: less than 100, 000 years, transitional forms may not be preserved because it is rapid, descendent fossil is right above ancestral fossil. Compared to gradual where there are different descendent fossil forms in different layers where it leads up to final. What might drive rapid change: stasis phenomenon of types of living creatures showing little or no change over long periods of time. Smaller will have a more obvious change while larger will most likely be in stasis. Because of genetic drift, certain traits being selected. The change may have taken a long time but the jump from one species to the other in the layer of rocks is almost immediate.
