BIOB51H3 Lecture Notes - Lecture 4: Burgess Shale, Radiometric Dating, Radioactive Decay
2 Mar 2020
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Lecture 4: role of geology and paleontology in understanding the history of life. Earth is not static, magma moves up and down, driving the movement of tectonic plates across earth"s surface. [age (mya) epoch period era eon], association them with time blocks delineated by geological and biological events. Radiometric dating has allowed geologists to precisely date the boundaries between these geological periods. Many elements have stable and unstable isotopes (determined by the number of neutrons) Unstable isotopes have a fixed probability of decay. Isotopes with high decay probabilities decay rapidly, isotopes with low decay probabilities decay slowly. A vast museum of fossils: fossil record contains incomplete chain of fossils. Biob51h3-s: fossils allow us to learn about extinct species, (e. g. ) By calculating the ages of layers of volcanic ash above and below a fossil, they can establish upper and lower bounds for when it formed.
