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Slide 2 Slide 3 Definition: the total number of species, the variability of their genes (DNA), and the ecosystems in which they live. Biodiversity emphasizes interactions ecosystems depend on all roles carried out by organisms living within them. Slide 4 Biodiversity provides more than just feel good incentives for us. Many organisms serve invaluable functions. Functions that serve humans directly define direct value for biodiversity. Its species specific Ex.Wood from trees, silk from silkworms, antibiotics from molds Functions of the WHOLE ecosystem that serves humans are known as indirect value Ex. Water storage in a forest, carbon sinks in forests, biogeochemical cycles Slide 5 (27.5) Slide 6 Slide 7 Definition: the study of grouping living things based on their shared characteristics. Each organism is placed into larger and larger categories called taxa (plural form of taxon). Carl Linnaeus was a HUGE contributor to this. Slide 8 Slide 9 In modern biology, we use the following taxa/categories (from LEAST specific to MOST specific): Domain Kingdom Phylum Class Order Family Genus Species There are only 3 domains, but around 2 million species (discovered so far). Some estimates place the number of species on Earth at 8.7 million. **As you go lower down the ranking, the number of taxa increases.** Slide 10 Definition: the assignment of a specific scientific name to an organism. An organisms name is usually binomial (contains two words) its Genus and its species are listed. Linnaeus created this approach. Eg: Homo sapiens, Escherichia coli These can be abbreviated Eg: H. sapiens, E. coli Slide 11 Definition: the evolutionary relationship among organisms. The goal of systematics is to put closely-related species into similar groups. Classification should reflect phylogeny. Members of the same family should be more related than members of a different family. Slide 12 Living things are divided into five kingdoms based on: Whether or not their cells have nuclei. How many cells theyre made up of. How they obtain their food/nutrition. Slide 13 Slide 14 Suggests that monerans (bacteria, archaea) evolved first and dont have nuclei. Protists evolved from monerans. Plants, animals, and fungi share some common, protist ancestor. This system is now considered to be inaccurate, though. Slide 15 Carl Woeses analysis of bacteria suggested that they should be divided into two kingdoms: Eubacteria (also called true bacteria) and Archaebacteria This caused the creation of a sixth kingdom. Slide 16 Evidence in DNA and RNA (ribonucleic acid) helps to sort living things into larger domains. Domains are based on RNA, molecular evidence, and cell structures. The three domains are: Eukarya, Bacteria, and Archaea. Slide 17 Slide 18 How to figure out which category is the right one Slide 19 If something is true about a category, then it MUST be true for ALL members of that category. This is called categorical reasoning. It is the basis for classification. It looks like this: Premise: All wizards wear capes. Given: Miss Mandrick wears a cape. Conclusion: Miss Mandrick is a wizard. Slide 20 Example: Premise: All birds are vertebrates. Given: A robin is a bird. Conclusion: A robin is a vertebrate. Using this example, construct an argument to show that Miss Mandrick is a mammal. Slide 21 1) Construct a categorical argument to show that a spruce tree is a plant. 2) Consider this argument: Premise: All horses are herbivores. Given: Organism X is a herbivore. Conclusion: Organism X is a horse. Is this argument correct? Why or why not? Slide 22 All bacteria are prokaryotes (they have no nuclei) and unicellular (a whole bacterium is made up of just one cell). Found in nearly every environment you can think of. Slide 23 Also unicellular prokaryotes. Have a different cell wall and membrane compared to bacteria. Tend to inhabit extreme conditions Highly salty waters Hot springs Extremely cold waters More closely-related to Eukarya than to bacteria. Slide 24 All of these organisms are eukaryotes (have cells that contain a nucleus). Can be either unicellular (protists, yeasts) or multicellular (plants, animals, many fungi). This domain is made up of 4 of the original five kingdoms (Plantae, Animalia, Fungi, and Protista). Slide 25 Also called phylogenetics. This is the new direction in classification. Organisms are put into groups called clades. Each clade contains an ancestor and ALL species that have descended from it. Continued Slide 26 CLADISTICS TRADITIONAL VIEW (TAXONOMY AND SYSTEMATICS) Organisms arranged by ancestry (shared genes, common ancestors). Grouped into different clades. Physical characteristics within a clade can be VERY different. Organisms arranged by physical characteristics. Grouped into phyla, classes, orders, etc. Physical characteristics in groups tend to be similar. Slide 27 Note that in this diagram, 7 distinct animals all belong to a single clade! Slide 28 CAREFUL! Even though the cladogram used one trait at a time to arrange the organisms, real phylogeneticists will use much more data. Data for creating clades includes: Physical characteristics DNA sequences and genes RNA sequences Slide 29 Cladogram assignment. Slide 30 D.5.7 Outline the methods used to construct cladograms and the conclusions that can be drawn from them AND D.5.8 Construct a simple cladogram These two cladograms are identical (although they dont look it) The shape and the order of the terminal nodes does not matter. The only information to be gathered from the cladograms below is the order of nesting of sister clades and the relative relatedness of species http://commons.wikimedia.org/wiki/File:Identical_cladograms.sv g Slide 31 Human Chimp Gorilla Root Terminal nodes Sister clades: have a common ancestor Out group: Defines the ancestral characters Nodes: Common ancestors Slide 32 http://www.ncbi.nlm.nih.gov/About/primer/phylo.html Branches on a cladogram can be scaled or unscaled. If the branches are scaled, the length of the branch often indicates how much evolutionary change has occurred in a species since it split from its sister clade at the last node Slide 33 http://www.ncbi.nlm.nih.gov/About/primer/phylo.html Rooted cladograms show evolutionary relationships. Unrooted trees just show the relationships between clades Slide 34 CharactersSpongeJellyfishFlatwormEarth- worm SnailFruit flyStarfishHuman Cells with flagellaXXXXXXXX SymmetryXXXXXXX Bilateral symmetryXXXXXX MesodermXXXXX Head develops firstXXX Anus develops firstXX Segmented bodyXX Calcified shellX Chitinous ExoskeletonX Water Vascular systemX VertebraeX Now you try! Make a Venn diagram for this data. Slide 35 Cells with flagella: Sponge Symmetry: Jellyfish Bilateral symmetry: Flatworm Mesoderm Head develops first Anus develops first Segmented Body: Earthworm Calcified Shell: Snail Chitinous exoskeleton: Fruit fly Water Vascular system: Starfish Vertebrae: Human Slide 36 Flagella Mesoderm Bilateral symmetry Symmetry Vertebrae Anus develops first Chitinous shell Head develops first SpongeStarfishFruit flySnail Flat- worm Earthworm JellyfishHuman Water vascular system Calcified shell Segmented body Slide 37 Flagella Mesoderm Bilateral symmetry Symmetry Vertebrae Anus develops first Chitinous shell Head develops first SpongeStarfishFruit flySnail Flat- worm Earthworm JellyfishHuman Water vascular system Calcified shell Segmented body Unnecessary to differentiate Snail. Snail is the only species with head develops first and without segmented body Unnecessary to use two characteristics to differentiate between Starfish and Human. Either would do the trick Unnecessary to use two characteristics to split lineages Slide 38 Cladograms are made by compiling data on homologous characteristics shared by species. These characteristics can be structural, physiological and/or biochemical. With increasing taxa comes increasing complexity. So software is often used to find the best possible tree that has the fewest evolutionary steps. Slide 39 This cladogram for bacteria is computer generated Slide 40 Slide 41 Slide 42 Slide 43 Slide 44 Slide 45 Slide 46 Slide 47 Slide 48