Modern Classification: Cladograms

1. Modern Classification: Cladograms SB3c Explain the evolutionary basis of modern classification systems

2. Basis for Modern Classification • Evolutionary Relationships • Homologous structures (same structure, different function) • Similar embryo development • Similarity in DNA, RNA, or the amino acid sequence of Proteins

3. Homologous Structures show Similarities in mammals.

4. Similarities in Vertebrate Embryos

5. DNA testing to determine relationships

6. Cladograms

7. Cladogram – diagram that shows the evolutionary relationships between organisms • Derived characters - traits or characteristics that have evolved • Individual organisms “branch off” when they do not share the derived character in question

8. Feathers

9. Let’s try this… • Cladograms can be constructed for any group of organisms. • kangaroo, earthworm, amoeba, lizard, cat, sponge, and salmon. • Each of these creatures has an evolutionary relationship to one another.

10. They all share a common origin. • their current forms are all derived from branching events somewhere in the phylogenetic past.

11. Complete the characteristic chart • Use + to indicate the presence of a characteristic in the organism • Use – to indicate that the organism does not have the characteristic

12. earthworm kangaroo

13. amoeba lizard

14. cat sponge

15. salmon

17. Ok • Look at the organisms to see how many of the derived characters they share: • Amoeba has 0 • Sponge has 1 • Salmon has 3 • Etc.

18. Using these patterns of shared derived characters, a cladogram can be constructed as a series of branches. • At every branch, one of the organisms that does not share a common character with the rest of the group is "branched off" into its own clade.

19. cat sponge salmon earthworm lizard kangaroo amoeba

20. cat cat cat sponge salmon earthworm lizard kangaroo amoeba salmon salmon earthworm lizard lizard kangaroo kangaroo

21. cat salmon earthworm lizard kangaroo sponge Multicelled amoeba

22. cat cat cat salmon salmon salmon earthworm lizard lizard lizard kangaroo kangaroo kangaroo earthworm earthworm sponge sponge amoeba Segmented Multicelled sponge amoeba Multicelled

23. cat Segmented Jaws lizard kangaroo salmon earthworm sponge amoeba Multicelled

24. cat lizard salmon earthworm sponge Limbs amoeba Segmented Jaws Multicelled kangaroo lizard salmon earthworm earthworm sponge sponge sponge amoeba amoeba amoeba

25. cat kangaroo lizard salmon earthworm sponge Limbs Hair amoeba Segmented Jaws Multicelled

26. cat kangaroo lizard salmon earthworm sponge Limbs Hair Placenta amoeba Segmented Jaws Multicelled