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Protist Evolution. BIOL 1407. Domain Eukarya is Sister Taxon to Domain Archaea. Prokaryotes vs. Eukaryotes. Evolution of Cytoskeleton. Some bacteria have proteins similar to actin & tubulin Actin = MreB Tubulin = FtsZ More info: http://www.palaeos.com/Eukarya/Eukarya.Origins.3.html
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Protist Evolution BIOL 1407
Evolution of Cytoskeleton • Some bacteria have proteins similar to actin & tubulin • Actin = MreB • Tubulin = FtsZ • More info: • http://www.palaeos.com/Eukarya/Eukarya.Origins.3.html • http://www.esrf.eu/UsersAndScience/Publications/Highlights/2001/life-sciences/LS10.html
Endomembrane System • Endomembrane system of eukaryotes: • Nuclear envelope • ER • Golgi • Vesicles & vacuoles • ↑ Surface Area
Evolution of Endomembrane System • Some bacteria: plasma membrane folded to inside
Primary Endosymbiosis • Formed when host cell engulfs another prokaryote • Mutualistic relationship develops • Become a single cell
Evidences for Primary Endosymbiosis • Size • Enzymes and transport systems • Binary fission • Circular chromosome • Genome still active • Ribosomes • DNA sequences
Evolution of Mitochondria • Molecular evidence • Alpha proteobacteria is sister taxon to mitochondria
Evolution of Chloroplasts • Molecular evidence • Cyanobacteria is sister taxon to chloroplasts
Secondary Endosymbiosis • Eukaryotic cell engulfed by another eukaryote • Evolves into an organelle
Fossil Evidence • Earliest body fossils: 2.1 bya • Fossil cysts (acritarchs) of dinoflagellate ancestors • Molecular fossils: 2.7 bya • Sterols (Acritarch)
The End Unless otherwise specified, all images in this presentation came from: Campbell, et al. 2008. Biology, 8th ed. Pearson Benjamin Cummings.