Evidence of Evolution 1.Fossil Evidence 2.Biochemical Evidence 3.Anatomical Evidence 4.Embryological Evidence 5.Geographic Distribution Fossil Evidence How are fossils formed? Why dont fossils form? Relative vs. Absolute dating Radioactive dating Laetoli Footprints Your job- read the background essay, watch the video, and complete the discussion questions Relative Dating vs. Absolute Dating Radioactive Dating ISOTOPES- Half-life = Naturally occuring radioactive isotopes (called the parent isotope) disintegrate at specific rates to make other isotopes (called daughter isotopes). The amount of time it takes for half the quantity of the original isotope to decay is constant, no matter how much is present at the beginning. Based on this principle, the age of geologic events can be measured. Biochemical Evidence Anatomical Evidence of Evolution Homologous Structures- descent with modification Vestigial Structures The Hands of Primates Embryologic evidence Darwins Finches Geographic Distribution Natural Selection It is not the strongest of the species that survive, nor the most intelligent, but the one most responsive to change. Charles Darwin