2: Classification & Phylogeny

• Eukarya


  Domain of all organisms whose cells have nuclei, including protists, plants, fungi, and animals
• Archaea


  Domain of unicellular prokaryotes that have cell walls that do not contain peptidoglycan
• Bacteria


  Single-celled organisms that lack a nucleus; prokaryotes
• Metabolism


  All of the chemical reactions that occur within an organism
• Replication


  Copying process by which a cell duplicates its DNA
• Three Domains of Life

  Bacteria, Archaea, and Eukarya, based on ribosomal RNA gene sequences
• Fin whale


  An endangered species with the Latin name Balaenoptera physalus (Linnaeus, 1758)
• Biological species concept


  Defines a group of interbreeding natural populations that are reproductively isolated but phenotypically similar
• Hierarchical Classification


  Linnaeus's system that groups species into increasingly broad categories, from domain to species
• Carl Linnaeus

  Founder of binomial nomenclature and the father of modern taxonomy
• John Ray


  Defined species as organisms capable of interbreeding and producing fertile offspring
• Aristotle


  Classified organisms based on qualities like shape, ability to do harm, and habitat
• Taxonomy


  Branch of biology that names and groups organisms based on characteristics and evolutionary history
• Binomial nomenclature


  System of naming species with a genus and species name, underlined or italicized, developed by Linnaeus
• Diversity of Life

  Resulted in 1.6 million identified types of plants and animals, with 3-10 million unidentified organisms
• Geographical evidence of evolution

  Includes the distribution of plant and animal life on major land masses, showing independent evolution
• Biological evidence of evolution

  Includes anatomical, embryological, immunological, and biochemical affinities suggesting relatedness by descent
• Geological evidence of evolution

  Includes the fossil record showing slow change over time
• Natural selection


  Process by which nature selects 'fit' individuals of a species and rejects the 'unfit', leading to evolution
• Theory of Evolution


  Provides an explanation of how the variety of organisms present today came into existence
• Endosymbiotic theory


  Explains the origins of chloroplasts and mitochondria in eukaryotes through a mutually beneficial relationship
• Photosynthetic pigments

  Contained in thylakoids, infoldings of the membrane in cyanobacteria, no chloroplasts
• Stromatolites


  Oldest fossils, fossilized mats of prokaryotes resembling modern microbial colonies/biofilms
• Cyanobacteria


  Photosynthetic bacteria that appeared about 3.5 billion years ago and produced oxygen
• Anaerobic prokaryotes


  First life forms, e.g. methane producing archaea-bacteria, appeared about 3.5 billion years ago
• Replication and metabolism


  Key properties of life that may have appeared together
• Protocells


  Fluid-filled vesicles with a membrane-like structure, formed by lipids and organic molecules in water
• Affinities 


  Features suggesting that organisms are related by descent.