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The Diversity of Life I. An Overview The Diversity of Life I. An Overview A. Classifying Organisms The Diversity of Life I. An Overview A. Classifying Organisms Initially, using a Platonic, typological concept, Linnaeus and others created a nested, hierarchical system. The Diversity of Life I. An Overview A. Classifying Organisms Initially, using a Platonic, typological concept, Linnaeus and others created a nested, hierarchical system. Evolution explained this nested pattern as a consequence of descent from common ancestors. The Diversity of Life I. An Overview A. Classifying Organisms Initially, using a Platonic, typological concept, Linnaeus and others created a nested, hierarchical system. Evolution explained this nested pattern as a consequence of descent from common ancestors. Modern biologists view the classification system as a means of showing the phylogenetic relationships among groups. The Diversity of Life I. An Overview Genus Felis A. Classifying Organisms Initially, using a Platonic, typological concept, Linnaeus and others created a nested, hierarchical system. Evolution explained this nested pattern as a consequence of descent from common ancestors. Modern biologists view the classification system as a means of showing the phylogenetic relationships among groups. Genetic relatedness should be the basic for biological classification... Genus Panthera Family Felidae The Diversity of Life I. An Overview A. Classifying Organisms B. Kingdoms The Diversity of Life I. An Overview A. Classifying Organisms B. Kingdoms Phylogenetic analysis revealed that the "Monera" were an incredibly diverse group genetically. Also, one subgroup - the Archea, were more similar to Eukaryotes than to the other group of prokaryotes (the 'Eubacteria'). The Diversity of Life I. An Overview A. Classifying Organisms B. Kingdoms Phylogenetic analysis revealed that the "Monera" were an incredibly diverse group genetically. Also, one subgroup - the Archea, were more similar to Eukaryotes than to the other group of prokaryotes (the 'Eubacteria'). This required a new way of looking at the most fundamental groupings of life - and the introduction of a new term: Domains The Diversity of Life I. An Overview A. Classifying B. Kingdoms C. Domains The Diversity of Life I. An Overview A. Classifying B. Kingdoms C. Domains Curiously, the very root of life may be invisible to genetic analysis. Bacteria transfer genes by division (to 'offspring'), but they also transfer genes "laterally" to other living bacteria. This makes reconstructing bacterial phylogenies difficult. The Diversity of Life I. An Overview A. Classifying B. Kingdoms C. Domains Also, early evolution involved bacterial symbioses and gene sharing between hosts and symbionts The Diversity of Life I. An Overview A. Classifying B. Kingdoms C. Domains So, reconstructing the patterns of relatedness among these ancient life forms is difficult. The Diversity of Life I. An Overview 4.5 bya: Earth Forms D. Timeline The Diversity of Life I. An Overview 4.0 bya: Oldest Rocks 4.5 bya: Earth Forms D. Timeline 4.0 bya: Oldest Rocks 3.8 bya: Oldest Fossils 4.5 bya: Earth Forms The Diversity of Life I. An Overview D. Timeline The Diversity of Life I. An Overview 4.0 bya: Oldest Rocks 3.8 bya: Oldest Fossils 4.5 bya: Earth Forms D. Timeline Stromatolites - communities of layered 'bacteria' 2.3-2.0 bya: Oxygen in Atmosphere 4.0 bya: Oldest Rocks 3.8 bya: Oldest Fossils 4.5 bya: Earth Forms The Diversity of Life I. An Overview D. Timeline 1.8 bya: first eukaryote 2.3-2.0 bya: Oxygen 4.0 bya: Oldest Rocks 3.8 bya: Oldest Fossils 4.5 bya: Earth Forms The Diversity of Life I. An Overview D. Timeline 0.9 bya: first animals 1.8 bya: first eukaryote 2.3-2.0 bya: Oxygen 4.0 bya: Oldest Rocks 3.8 bya: Oldest Fossils 4.5 bya: Earth Forms The Diversity of Life I. An Overview D. Timeline 0.5 bya: Cambrian 0.9 bya: first animals 1.8 bya: first eukaryote 2.3-2.0 bya: Oxygen 4.0 bya: Oldest Rocks 3.8 bya: Oldest Fossils 4.5 bya: Earth Forms The Diversity of Life I. An Overview D. Timeline 0.5 bya: Cambrian 0.24 bya:Mesozoic 0.9 bya: first animals 1.8 bya: first eukaryote 2.3-2.0 bya: Oxygen 4.0 bya: Oldest Rocks 3.8 bya: Oldest Fossils 4.5 bya: Earth Forms The Diversity of Life I. An Overview D. Timeline 0.5 bya: Cambrian 0.24 bya:Mesozoic 0.065 bya:Cenozoic 0.9 bya: first animals 1.8 bya: first eukaryote 2.3-2.0 bya: Oxygen 4.0 bya: Oldest Rocks 3.8 bya: Oldest Fossils 4.5 bya: Earth Forms The Diversity of Life I. An Overview D. Timeline 0.5 bya: Cambrian 0.24 bya:Mesozoic 0.065 bya:Cenozoic 0.9 bya: first animals 1.8 bya: first eukaryote 2.3-2.0 bya: Oxygen 4.0 bya: Oldest Rocks 3.8 bya: Oldest Fossils 4.5 bya: Earth Forms The Diversity of Life 4.5 million to present I. An Overview D. Timeline (1/1000th of earth history) The Diversity of Life 5 million to present I. An Overview 0.5 bya: Cambrian 0.24 bya:Mesozoic 0.065 bya:Cenozoic 0.9 bya: first animals 1.8 bya: first eukaryote 2.3-2.0 bya: Oxygen 4.0 bya: Oldest Rocks 3.8 bya: Oldest Fossils 4.5 bya: Earth Forms D. Timeline for 1/2 of life's history, life was exclusively bacterial.... what were they doing? Spheres, rods, and spirals were all they could come up with?? Let's look...