1. Classification WAL: about classification, the binomial system and taxonomy. All Most Some What is a species and how are species named? What are the principles of classification? How is classification related to evolution?

2. What is classification? Organising living organisms into groups We need to do this as scientists have already named around 1.8 million different living organisms

3. What is a species?

4. How do we name a species? Used to be due to certain features of the organism Led to the same name being used for different species in different parts of the world 200 years ago Linnaeus (a Swedish botanist) came up with a universal system

5. The Binomial System Uses Latin or Greek names The first name is the generic name and this is the Genus to which the organism belongs – (Similar to the surname of a person) The second name is the specific name and this is the species. – (Similar to the first name of a person)

6. Canis lupus Equus caballus Protea caffra

7. The Binomial System: Rules The specific name is never shared with another species within the genus. The names are printed in italics or underlined if hand written The first letter of the generic name is capitalised, and the specific name is not

8. Principles of classification The grouping of species is called classification, whereas the practice of biological classification is called taxonomy

9. Types of classification Artificial classification: Divides organisms by physical characteristics, such as size or number of legs. Describes by the same function, not the same evolutionary origin What are the problems with this?

10. Types of classification Natural classification: Based upon the evolutionary relationships Classifies species using shared features derived from their ancestors Arranges the groups into a hierarchy – groups contained within larger groups with no overlap

12. Taxonomy Each group within biological classification is called a taxon (pl. taxa). The largest is the kingdom The largest group in a kingdom is a phylum – classed by the body plan of the organism Within phyla there are classes

13. Taxonomy Classes are then sub-divided into orders Orders are divided into families Each family is divided into genera Each genus is divided into species

14. King Prawn Curry Or Fat Greasy Sausages? RankPin mouldSweet PeaTiger KingdomFungiPlantaeAnimalia PhylumZygomycotaAngiospermophytaChordata ClassZygomycetesDicotyledonaMammalia OrderMurolalesRosalesCarnivora FamilyMuroraceaeFabaceaeFelidae GenusMurcorLathyrusFelix speciesmucedoodoratustigris

16. Phylogeny This is the evolutionary relationship between organisms The phylogeny reflects the evolutionary branch that led to the organism Usually shown as a tree like diagram, a phylogenetic tree

18. To do: Create your own model of a phylogenic tree Arrange the objects into an evolutionary tree (make sure you follow the rules!) Once you have finished, you can glue the pictures down... Draw lines in between! Be prepared to justify your choices. 15 minutes

19. Problems defining species… What should you do about different breeds of dog? Species are not fixed Many species are extinct Some species are sterile…

20. Ligers Lions and tigers are also able to mate to produce an animal known as a ‘liger’. Some ligers are fertile and some are not, so it is difficult to classify lions and tigers,are they separate, or part of the same species?

21. The mule problem…

22. A mule is the produce of a horse and a donkey mating As horses and donkeys are different species, a mule is sterile They have 63 chromosomes – 32 from the horse and 31 from the donkey As the number of chromosomes is odd, meiosis cannot form gametes

23. The mule problem… Am I a distinct species?

24. Learning Check! 1.The phylogenic tree to the right shows the evolutionary history of some mammals. a.Which species on the genetic tree are most closely related to humans? Explain how you know this. b. Which animal is a close relative of both camel and deer? 2.Define a species. 3.Complete the table for classification of humans. 4.Give three reasons why scientists can find it hard to classify organisms as members of a distinct species. PhylumFamily AnimaliaChordatiaMammaliaPrimatesHomidinaeHomosapiens

25. Learning Check! Self assessment 1.a. Green Monkey (1 mark) Because it’s the closest to humans on the tree. (1 mark) b. Pig (1 mark) 2. A group of similar organisms (1 mark) able to reproduce to give fertile offspring. (1 mark) 3. Max 5 marks available, 1 mark for each correct answer. KingdomPhylumClassOrderFamilyGenusSpecies AnimaliaChordatiaMammaliaPrimatesHomidinaeHomosapiens 4. Max 3 marks available. E.g You can’t study the reproductive behaviour of extinct species (1 mark) Some species reproduce asexually (1 mark) There are practical and ethical issues involved in studying some reproductive behaviour (1 mark)

26. You should be able to… Define what we mean by a species Explain the system of naming species Outline the principles of classification – Natural classification and artificial Explain what is meant by taxonomy and phylogeny Be able to interpret a phylogenetic tree