1. The Origin of Species

4. Allopatric Speciation Single species (white mice); homogeneous habitat Geographical barrier (impassable river); isolated populations Genetic drift; genetic divergence; tan vs white mice Barrier removed (river dries up); mix but don’t interbreed (a) (b) (c) (d)

5. Sympatric Speciation Single species (white mice); homogeneous habitat (a) Climate change; two habitats; isolated because don’t mix (b) Environmental pressure to adapt; genetic divergence; tan vs white mice (c) Sufficient divergence; now different species (d)

7. Speciation by Polyploidy Diploid Gamete Meiosis Diploid Gametes Viable Tetraploid Zygote Viable Diploid Gametes Haploid Gamete Viable Triploid Zygote Meiosis (fails) Triploids can’t do meiosis; No viable gametes. Tetraploid Plant Tetraploid Plant Diploid Plant Meiosis Fertilization Meiosis Fertilization

8. Interpreting an Evolutionary Tree Lines that don't reach the top represent extinct species. Forks represent speciation events. Each line represents a species. Lines that reach the top represent existing species. Steeper slope represents slow phenotypic change. More horizontal slope represents rapid phenotypic change.

9. Systematics: Seeking Order Amidst Diversity

15. Microscopic Structures Help to Classify Organisms (a) (b) (c) Bristles on a marine worm “ Teeth” on a snail’s radula Shape and surface features on a pollen grain

16. Similarity of Human and Chimp Chromosomes H = Human C = Chimp

18. The Tree of Life

19. Representative Prokaryotes Vibrio cholerae of the domain Bacteria Methanococcus jannaschi of the domain Archaea

20. The Concept of Monophyly Monophyletic NOT Monophyletic (a) (b) (c) Reptiles not Monophyletic

21. Relatedness by DNA Sequences

22. The Origin of HIV Virus

23. The End