100 likes | 207 Views
Evidence of evolution. Fossil Record Fossil- Organism or evidence of an organism preserved in rock. Fossil formation. Sedimentary rock Superposition Older fossils are found in lower layers of rock Younger fossils in upper layers Amber. Geologic Time Scale.
E N D
Evidence of evolution • Fossil Record • Fossil- • Organism or evidence of an organism preserved in rock
Fossil formation • Sedimentary rock • Superposition • Older fossils are found in lower layers of rock • Younger fossils in upper layers • Amber
Geologic Time Scale • A time frame based on the fossil record • Eras (4) • Cenozoic • Mesozoic • Paleozoic • Precambrian • Periods • Epochs
Dating • Determining the age of rock and fossils • Relative age • Used to determine the relative age • Compare layers of rock
Dating • Absolute dating • (radioactive dating) • Used to determine the actual date • Uses the half life to determine actual age • Half life- time needed for half the radioactive atoms in a sample to decay • Carbon-14= 5,770 yrs • Uranium-238= 4.5 billion yrs
Other evidence showing relationships • Comparative anatomy • Homologous structures • Vestigial structures • Comparative embryology • Comparative biochemistry
Evolution in Action • Caribbean Anole Lizards • 3 species • On tree trunks & ground • On tree branches • On grass
Evolution in Action • Other Islands show similar body types in other species of lizard • Convergent Evolution • Process where different species evolve similar traits
Evolution in Action • Divergent Evolution • Process in which the descendants of a single ancestor evolve into species that fit different parts of the environment
Evolution in Action • Adaptive Radiation • Species undergo divergent evolution until many parts of the environment are filled • Ex. Darwin’s Finches