BIO153H5 Lecture Notes - Lecture 2: Paleozoic, Mesozoic, Heterochrony
7/1/2017
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BIO 153 Lecture 2
Life’s Timeline
The Cambrian explosion
Chapter 25.1 –25.3 & 25.6
building blocks of life were made in early
atmosphere:
•Urey - Miller’s (1953) primordial
soupexperiments recreated
early earth oditios ale to
make monomers:
•made all 20 amino acids, sugars,
lipids, pyrimidines, purines
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7/1/2017
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Conditions on Early Earth
•How could life have evolved?
•What role might volcanoes have played?
Life’s Tielie: The Prearia
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7/1/2017
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Oxygen –where did it come from?
•Single-celled organisms with a toxic waste product!
Life’s Tielie: The Paleozoi Era
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