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Discover the hierarchical system of classifying organisms, from Linnaeus' typological concept to modern phylogenetic analysis. Explore the genetic relationships between kingdoms and domains, and learn about the challenges in reconstructing ancient life forms.
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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 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 Felis * * 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 A. Classifying B. Kingdoms C. Domains - "Ring of Life" hypothesis (2004)
The Diversity of Life I. An Overview D. Timeline 4.5 bya: Earth Forms
The Diversity of Life I. An Overview D. Timeline 4.0 bya: Oldest Rocks 4.5 bya: Earth Forms
The Diversity of Life I. An Overview D. Timeline 4.0 bya: Oldest Rocks 3.5 bya: Oldest Fossils 4.5 bya: Earth Forms
The Diversity of Life I. An Overview D. Timeline 4.0 bya: Oldest Rocks 3.5 bya: Oldest Fossils 4.5 bya: Earth Forms Stromatolites - communities of layered 'bacteria'
The Diversity of Life I. An Overview D. Timeline 2.3-2.0 bya: Oxygen in Atmosphere 4.0 bya: Oldest Rocks 3.4 bya: Oldest Fossils 4.5 bya: Earth Forms
The Diversity of Life I. An Overview D. Timeline 2.3-2.0 bya: Oxygen 1.8 bya: first eukaryote 4.0 bya: Oldest Rocks 3.4 bya: Oldest Fossils 4.5 bya: Earth Forms
The Diversity of Life I. An Overview D. Timeline 2.3-2.0 bya: Oxygen 0.9 bya: first animals 1.8 bya: first eukaryote 4.0 bya: Oldest Rocks 3.4 bya: Oldest Fossils 4.5 bya: Earth Forms
The Diversity of Life I. An Overview D. Timeline 2.3-2.0 bya: Oxygen 0.9 bya: first animals 1.8 bya: first eukaryote 0.5 bya: Cambrian 4.0 bya: Oldest Rocks 3.4 bya: Oldest Fossils 4.5 bya: Earth Forms
The Diversity of Life I. An Overview D. Timeline 2.3-2.0 bya: Oxygen 0.9 bya: first animals 1.8 bya: first eukaryote 0.5 bya: Cambrian 0.24 bya:Mesozoic 4.0 bya: Oldest Rocks 3.4 bya: Oldest Fossils 4.5 bya: Earth Forms
The Diversity of Life I. An Overview D. Timeline 2.3-2.0 bya: Oxygen 0.9 bya: first animals 1.8 bya: first eukaryote 0.5 bya: Cambrian 0.24 bya:Mesozoic 0.065 bya:Cenozoic 4.0 bya: Oldest Rocks 3.4 bya: Oldest Fossils 4.5 bya: Earth Forms
The Diversity of Life I. An Overview D. Timeline 4.5 million to present (1/1000th of earth history) 2.3-2.0 bya: Oxygen 0.9 bya: first animals 1.8 bya: first eukaryote 0.5 bya: Cambrian 0.24 bya:Mesozoic 0.065 bya:Cenozoic 4.0 bya: Oldest Rocks 3.4 bya: Oldest Fossils 4.5 bya: Earth Forms
The Diversity of Life I. An Overview D. Timeline 5 million to present 2.3-2.0 bya: Oxygen 0.9 bya: first animals 1.8 bya: first eukaryote 0.5 bya: Cambrian 0.24 bya:Mesozoic 0.065 bya:Cenozoic 4.0 bya: Oldest Rocks 3.4 bya: Oldest Fossils 4.5 bya: Earth Forms 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...
The Diversity of Life I. An Overview II. An Overview of 'The Bacteria'
The Diversity of Life I. An Overview II. An Overview of 'The Bacteria'
The Diversity of Life I. An Overview II. An Overview of 'The Bacteria' The key thing about bacteria is their metabolic diversity. Although they didn't radiate much morphologically (spheres, rod, spirals), they DID radiate metabolically. As a group, they are the most metabolically diverse group of organisms.
The Diversity of Life I. An Overview II. An Overview of 'The Bacteria' The key thing about bacteria is their metabolic diversity. Although they didn't radiate much morphologically (spheres, rod, spirals), they DID radiate metabolically. As a group, they are the most metabolically diverse group of organisms. A. Oxygen Demand all eukaryotes require oxygen.
The Diversity of Life I. An Overview II. An Overview of 'The Bacteria' The key thing about bacteria is their metabolic diversity. Although they didn't radiate much morphologically (spheres, rod, spirals), they DID radiate metabolically. As a group, they are the most metabolically diverse group of organisms. A. Oxygen Demand all eukaryotes require oxygen. bacteria show greater variability: - obligate anaerobes - die in presence of O2 - aerotolerant - don't die, but don't use O2 - facultative aerobes - can use O2, but don't need it - obligate aerobes - require O2 to live
The Diversity of Life I. An Overview II. An Overview of 'The Bacteria' The key thing about bacteria is their metabolic diversity. Although they didn't radiate much morphologically (spheres, rod, spirals), they DID radiate metabolically. As a group, they are the most metabolically diverse group of organisms. A. Oxygen Demand all eukaryotes require oxygen. bacteria show greater variability: - obligate anaerobes - die in presence of O2 - aerotolerant - don't die, but don't use O2 - facultative aerobes - can use O2, but don't need it - obligate aerobes - require O2 to live represents an interesting continuum, perhaps correlating with the presence of O2 in the atmosphere.
The Diversity of Life I. An Overview II. An Overview of 'The Bacteria' The key thing about bacteria is their metabolic diversity. Although they didn't radiate much morphologically (spheres, rod, spirals), they DID radiate metabolically. As a group, they are the most metabolically diverse group of organisms. B. Nutritional Categories:
The Diversity of Life I. An Overview II. An Overview of 'The Bacteria' The key thing about bacteria is their metabolic diversity. Although they didn't radiate much morphologically (spheres, rod, spirals), they DID radiate metabolically. As a group, they are the most metabolically diverse group of organisms. B. Nutritional Categories: - chemolithotrophs: use inorganics (H2S, etc.) as electron donors for electron transport chains and use energy to fix carbon dioxide. Only done by bacteria.
The Diversity of Life I. An Overview II. An Overview of 'The Bacteria' The key thing about bacteria is their metabolic diversity. Although they didn't radiate much morphologically (spheres, rod, spirals), they DID radiate metabolically. As a group, they are the most metabolically diverse group of organisms. B. Nutritional Categories: - chemolithotrophs: use inorganics (H2S, etc.) as electron donors for electron transport chains and use energy to fix carbon dioxide. Only done by bacteria. - photoheterotrophs: use light as source of energy, but harvest organics from environment. Only done by bacteria.
The Diversity of Life I. An Overview II. An Overview of 'The Bacteria' The key thing about bacteria is their metabolic diversity. Although they didn't radiate much morphologically (spheres, rod, spirals), they DID radiate metabolically. As a group, they are the most metabolically diverse group of organisms. B. Nutritional Categories: - chemolithotrophs: use inorganics (H2S, etc.) as electron donors for electron transport chains and use energy to fix carbon dioxide. Only done by bacteria. - photoheterotrophs: use light as source of energy, but harvest organics from environment. Only done by bacteria. - photoautotrophs: use light as source of energy, and use this energy to fix carbon dioxide. bacteria and some eukaryotes.
The Diversity of Life I. An Overview II. An Overview of 'The Bacteria' The key thing about bacteria is their metabolic diversity. Although they didn't radiate much morphologically (spheres, rod, spirals), they DID radiate metabolically. As a group, they are the most metabolically diverse group of organisms. B. Nutritional Categories: - chemolithotrophs: use inorganics (H2S, etc.) as electron donors for electron transport chains and use energy to fix carbon dioxide. Only done by bacteria. - photoheterotrophs: use light as source of energy, but harvest organics from environment. Only done by bacteria. - photoautotrophs: use light as source of energy, and use this energy to fix carbon dioxide. bacteria and some eukaryotes. - chemoheterotrophs: get energy and carbon from organics they consume. bacteria and some eukaryotes.
The Diversity of Life I. An Overview II. An Overview of 'The Bacteria' The key thing about bacteria is their metabolic diversity. Although they didn't radiate much morphologically (spheres, rod, spirals), they DID radiate metabolically. As a group, they are the most metabolically diverse group of organisms. B. Nutritional Categories: - chemolithotrophs: use inorganics (H2S, etc.) as electron donors for electron transport chains and use energy to fix carbon dioxide. Only done by bacteria. - photoheterotrophs: use light as source of energy, but harvest organics from environment. Only done by bacteria. - photoautotrophs: use light as source of energy, and use this energy to fix carbon dioxide. bacteria and some eukaryotes. - chemoheterotrophs: get energy and carbon from organics they consume. bacteria and some eukaryotes.
The Diversity of Life I. An Overview II. An Overview of 'The Bacteria' The key thing about bacteria is their metabolic diversity. Although they didn't radiate much morphologically (spheres, rod, spirals), they DID radiate metabolically. As a group, they are the most metabolically diverse group of organisms. C. Their Ecological Importance
The Diversity of Life I. An Overview II. An Overview of 'The Bacteria' The key thing about bacteria is their metabolic diversity. Although they didn't radiate much morphologically (spheres, rod, spirals), they DID radiate metabolically. As a group, they are the most metabolically diverse group of organisms. C. Their Ecological Importance - major photosynthetic contributors (with protists and plants)
The Diversity of Life I. An Overview II. An Overview of 'The Bacteria' The key thing about bacteria is their metabolic diversity. Although they didn't radiate much morphologically (spheres, rod, spirals), they DID radiate metabolically. As a group, they are the most metabolically diverse group of organisms. C. Their Ecological Importance - major photosynthetic contributors (with protists and plants) - the only organisms that fix nitrogen into biologically useful forms that can be absorbed by plants.
The Diversity of Life I. An Overview II. An Overview of 'The Bacteria' The key thing about bacteria is their metabolic diversity. Although they didn't radiate much morphologically (spheres, rod, spirals), they DID radiate metabolically. As a group, they are the most metabolically diverse group of organisms. C. Their Ecological Importance - major photosynthetic contributors (with protists and plants) - the only organisms that fix nitrogen into biologically useful forms that can be absorbed by plants. - primary decomposers (with fungi)
The Diversity of Life I. An Overview II. An Overview of 'The Bacteria' The key thing about bacteria is their metabolic diversity. Although they didn't radiate much morphologically (spheres, rod, spirals), they DID radiate metabolically. As a group, they are the most metabolically diverse group of organisms. C. Their Ecological Importance - major photosynthetic contributors (with protists and plants) - the only organisms that fix nitrogen into biologically useful forms that can be absorbed by plants. - primary decomposers (with fungi) - pathogens