BIO 1130 Study Guide - Final Guide: Trichoplax, Symmetry In Biology, Cambrian

• School: University of Ottawa
• Department: Biology
• Course: BIO 1130
• Professor: Jon Houseman

Document Summary

Permian 299-245 ma: mesozoic era (245-65 ma) Cenozoic era (most recent) (65 ma to present time) Land mass north america: sitting over equator, large continental shelf, shallow waters. Explosive time of evolution: abundance of fossils. Dissolved calcium dissolved silica (allowed fossilization) Organisms die along shoreline: no oxygen = no decomposition, rocks build up sediments = shales. Diversification (not a lot of competition: soft bodied- independent of mineral based fossilization, before cambrian: Feeding strategy= penetrating mat: (2) no limitations in resources, (3) homeotic gene explosion. 180 nucleotide sequences in all animals: except: homeotic genes (hox genes) duplicated, 8. Sequenced in order of which they appear in embryo: possibly responsible for bilaterally symmetry. First predictable pattern between generation: change in these genes = millions of years before cambrian. Fossils suggesting multicellular life prior to cambrian: doushantuo fossils (590-565 mya) Earlier than cambrian: edacarian fossils (580-542 mya) Last division of proterozoic = ediacaran period. Fractile: seen in smaller versions, repeating pattern.