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Topic 5.5

Topic 5.5. Classification. Why Classify?. How many ‘different sorts’ of living things are there on the planet?. How many species are there in the world?. Let’s start with some classification!. Take 5 minutes to write down ways in which we can classify the students in class today

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Topic 5.5

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  1. Topic 5.5 Classification

  2. Why Classify? • How many ‘different sorts’ of living things are there on the planet?

  3. How many species are there in the world?

  4. Let’s start with some classification! • Take 5 minutes to write down ways in which we can classify the students in class today • Key features of a classification key are that it must be clear, consistent, and easily implemented

  5. Why Classify? • In order to sort out and compare living things, we need to organise them into ‘manageable’ categories • A good classification system allows us to make generalisations AND organise our ideas about organisms • Classification involves giving every organism an AGREED NAME • Classification involves arranging organisms into apparently related organisms

  6. The American Robin (TurdusMigratorius) The European Robin (ErithracusRubecula)

  7. What is taxonomy?

  8. Taxonomy is the process of (scientific) classification Taxis: Greek for ‘Arrangement or Division’ ‘Nomos’: Greek for ‘Method or Law http://www.youtube.com/watch?v=F38BmgPcZ_I

  9. Systems used to classify living organisms • Linnaean Binomial Nomenclature system • Cladistics (Ancient Greek –Branch) • Phylogenetics

  10. The evolution of taxonomy… The Linnaean classification system was created long before scientists understood that organisms evolved. Because the Linnaean system is based on morphology (form and structure) rather than on evolutionary theory Most biologists are switching to a classification system that reflects the organisms' evolutionary history • Phylogenetic tree • Cladogram

  11. Cladistics • A taxonomic system based on common evolutionary ancestry • The Method of choice for classifying organisms, since it recognises and involves evolutionary theory • Developed since 1958 • Any group of organisms are related by descent from a common ancestor. • There is a bifurcating pattern of cladogenesis. • Change in characteristics occurs in lineages over time. • Cladistics introduction

  12. Phylogenetic tree • An ‘Evolutionary Tree’ • Shows inferred evolutionary relationship among species based on similarities/differences in their genetic material or physical appearance

  13. Linnaean Classification • Developed by Carl Linneaus • Swedish botanist & taxonomist • Is still used today, basis for classification and naming of all new species. • Based on physical traits, most of his classifications are still accurate. • http://www.youtube.com/watch?v=F38BmgPcZ_I

  14. Binomial Nomenclature • Each species is assigned a two part scientific name. • Written in italics • If handwritten, underline the name • First word is capitalized (Genus): NOUN • Second word is lowercase (Species): ADJECTIVE

  15. Binomial Nomenclature Homo sapiens Modern human Genus species Eretmochelysimbricata Hawksbill Turtle (imbricate: arrange so that they overlap like tiles) The genus name can be abbreviated if you have already used the full name in your text

  16. Linnaeus also defined four groups of humans, and the divisions were based on both physical and social traits. By 21st-century standards, his descriptions can be regarded as racist. • How does the social context of scientific work affect the methods and findings of research? • Is it necessary to consider the social context when evaluating ethical aspects of knowledge claims?

  17. There are seven (err, actually 8) levels of classification • Biological taxonomy is hierarchical • As we move from kingdom (domain) to phylum, all the way to species, organisms share more and more characteristics. • This system allows us to group organisms while also assigning unique species names.

  18. (Domain) King Philip Came Over For Good Spaghetti

  19. From Kingdom…

  20. From Kingdom… Linnaeus originally divided living things into 2 (then 3) kingdoms… • Animalia • Vegetalia (Plants) • Mineralia (Minerals, since abandoned) We now widely recognise FIVE kingdoms: • Kingdom Plantae(the plants) • Kingdom Animalia(the animals) • Kingdom Fungi (the fungi and moulds) • Kingdom Protocista(protozoa and alga) • Kingdom Prokaryote [Monera] (the euBacteria and archebacteria)

  21. Kingdom Animalia • Eukaryotic • Multicelluar • Heterotrophic • Terrestrial and aquatic • Sexual (a few are asexual) • Motile (a few are non-motile)

  22. Kingdom Plantae • Eukaryote • Multicellular • Autotrophic • Mostly terrestrial • Sexual and asexual • Nonmotile Mosses, Ferns, flowering plants, conifers

  23. Kingdom Fungi • Eukaryotic • Heterotrophic • Unicellular and multicellular • Mainly terrestrial • Asexual and sexual • Non-motile Mushrooms, puffballs, yeasts, rusts, water moulds

  24. Kingdom prokaryotae (Monera) • Prokaryotes • Heterotrophic and autotrophic • Anaesrobic and aerobic • Aquatic, terrestrial and aerosol • Mostly asexual • Mostly non-motile (one kind are motile)

  25. Kingdom Protoctistae (Protists) • Eukaryotes • Heterotrophic and autotrophic • Unicellular • Mostly aquatic • Mostly asexual • Motile and non-motile Protozoa, slime moulds, algae Brown Algae

  26. …To Species • A group of organisms which can interbreed and produce fertile offspring. • Species are named: Genus species • Heliconiuscharithonius • The smallest taxonomic group, though many subspecies are recognized. Might potentially interbreed if a barrier or other challenge was removed (ie: distance)

  27. 5.5.3 Distinguish between the following phyla of plants, using simple external recognition features: bryophyta, filicinophyta, coniferophytaand angiospermophyta. 

  28. 5.5.4 Distinguish between the following phyla of animals, using simple external recognition features: porifera, cnidaria, platyhelminths, annelida, mollusca and arthropoda. 

  29. Now…Action! • Go to Mr T@s slideshow in Classification • Start on Slide 14 (use the buttons at the bottom of the viewer to navigate).  By clicking on each picture you can link to information about each type of plant. • Slide 15: Make this table in your notebook. • Slide 15: Fill in this table.  If you're not sure what is meant by sporangia, look it up!  Don't simply write things down if you don't understand them.  You can also click back to slide 14 click on the image of the plant type to get more information.

  30. For tomorrow… • http://www.scenicoregon.com/webanic/play.htm • Use the Scenic Oregon I-animal website to write information about each specific animal phylum. You don’t need to prepare information about each class. • You will be sharing your information in class tomorrow

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