BIOL165 Lecture Notes - Lecture 4: Psilotum, Mesozoic, Paleozoic
10 Feb 2020
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Biological time clock of life on earth: oldest rocks ~4. 3 billion years old (earth is ~4. 5billion years old, prokaryotes 3. 5billin ya, oldest eukaryotes ~1. 5by old, humans ~200,000 ya. Hypothesis on the origin of life on earth: the rna world. Origins of free oxygen on earth: primary atmosphere hydrogen and helium, secondary reducing atmosphere developed from volcanic gases (dominated by anaerobes and chemotrophs, cyanobacteria increase in oxygen (aerobes dominant ~2bybp) Numerical breakdown of the species known on earth: animalia and plantae = majority of species. Size increase through time: 3billion years to reach a meter in length, blue whale is the largest living mammal. Variation in the amount of dna/cell: whisk fern (psilotum) largest amount of dna known, complexity is not tied to the amount of dna. International code of nomenclature of bacteria (and archaeans) International code of nomenclature (for algae, fungi and plants) prokaryotes.
