Biology 1001A Chapter Notes - Chapter 20: Evolutionary Developmental Biology, Phylogenetic Tree, Evolutionary Taxonomy
25 Nov 2016
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Chapter 20 understanding the history of life on earth. Distinct layers of sedimentary rock are called strata. Arranged in the order they were formed, oldest (bottom) to youngest (top). Fossils found in a stratum together died at roughly the same time. Fossilized bones are created when dissolved minerals enter the spaces within the bones are become solidified. Footprints can be fossilized when an organism walks across mud. Fossil timeline: stromatolites (3. 5 bya, blue-green prokaryotes and plants (2. 5 bya, unicellular eukaryotes (2 bya, multicellular eukaryotes (1. 2 bya, explosion of diversity (600 mya) Explosion of diversity comes with cambrian period, intro of skeletons. Early fossils exist due to the cell walls providing physical support and maintaining cell shape and structure. Vertebrates fossilized due to bones and some with teeth. Phylogeny: show the evolutionary history of a group of organisms in a diagram (tree) format. Phylogenetic tree: formal hypotheses identifying likely relationships among groups of organisms.
