BIOL 1202 Lecture : BIOL 1202 Class Notes 2 7 13
Document Summary
Skimmers birds that skim along surface of water looking for prey. Boundaries between units in the geologic time scale are marked by dramatic biotic change. 4500 million years ago: origin of earth: earth cool enough for crust to solidify, origin of life, oldest chemical evidence of life. 3500 mya oldest prokaryotic fossils: oldest chemical evidence of eukaryotes. 2500 mya oxygen produced by cyanobacteria begins to appear in atmosphere: oldest eukaryotic fossils. 1500 mya origins of multicellular eukaryotes: oldest animal fossils (near 500 mya) 500 mya plants and symbiotic fungi colonize land: extinction of dinosaurs (near 0 mya) **fossils are extremely important in setting up these evolutionary relationships in time. All existing species come from preexisting species (derivation of cell theory) Like library, we make it easy to categorize and classify organisms by going back in time and using fossils. Using life vs. nonlife to distinguish things on life (fiction vs. nonfiction: eukaryotic vs. prokaryotic.
