BIOLOGY 1M03 Lecture Notes - Dentition, Quadrupedalism, Faiyum Oasis
5 Apr 2013
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Document Summary
Modern humans have many complex adaptations, like grasping hands, bipedal locomotion (walking upright on two legs), toolmaking, language, and cooperation. Used to date age of volcanic rocks found in association with fossil material. Molten rock emerges from volcano at high temperatures. All of argon gas is boiled out of rock. Any argon present in rock must be due to decay of potassium. Ratio of potassium to argon can be used to date volcanic rock. Argon-argon dating: allows more accurate dating of single rock crystals, carbon-14 dating (radiocarbon dating) Based on unstable isotope of carbon that living animals and plants incorporate into their cells. Measure ratio of unstable carbon-14 to the stable isotope carbon-12. Once animal dies, carbon-14 decays into carbon-12 at a constant rate. Based on an effect of high-energy nuclear particles traveling through rock. Particles come from decay of radioactive material in and around the rock and from cosmic rays that bombard the earth from outer space.
