LIFESCI 1 Lecture Notes - Lecture 9: Macroevolution, Molecular Clock, Energy
Document Summary
Launch pad activities due by friday 10 am. For some stretches of dna, mutations build up at a reliable rate. Can help understand how much time has passed during periods of evolution. Environmental changes: clues from the fossil record help understand changes from the environment. Calibrate time: things that are deeper in the fossil are older. Habitat: some habitats are better at forming fossils than others. Taxonomic & tissue: some organisms" materials fossilize better than others. Abundance: abundant organisms will have an abundant fossil record while rare organisms will not be found in fossils. The ratio between carbon 14 and nitrogen 14 and understand the percent of nitrogen 14 remaining. Evidence of macroevolution: the origin of tetrapods. Tetrapods and fish share a common ancestor. Piecing together from a fish organism to tetraploid. Vestigial traits: doesn"t provide an adaptive advantage or disadvantage. Lowers competition among organisms creates new species. Eliminated dinosaurs (except birds) and made way for the age of mammals.
