Macroevolution

1. Macroevolution BIO 1113/1114 Oklahoma City Community College Dennis Anderson

2. Species 1.8 million species have been identified Probably 5 to 10 times that many are yet to be discovered

3. What is a Species? “Species are groups of actually or potentially interbreeding natural populations that are reproductively isolated from other such groups.” Barred Owl Spotted Owl

4. How Do New Species Arise? • Branching evolution occurs when a single “parent” species diverges into two species, Speciation 4

5. Population A Population B Gene Flow

6. Population A No Gene Flow Population B

7. Many Years Later Population A No Gene Flow Population B 7

8. If gene flow is maintained between separate populations, they will experience similar allele frequency changes, meaning they will evolve together. 8

9. If gene flow is drastically reduced for a long time period then populations will evolve separately. 9

10. Allopatric Speciation • There is no gene flow between the two geographically isolated populations • Each population changes with time • Changes result in new species.

11. The original populationstarted in the north andmigrated southward. The population split tothe east and west of theCentral Valley. Thentwo populations beganto evolve independently. Evolution ofeastern population. Central Valley Evolution ofwestern population. The east and west populationscame back together in SouthernCalifornia, but could no longerinterbreed (or produced infertilehybrid offspring). Figure 18.3

13. Sympatric Speciation • Different individuals may occupy different parts of the same environment • They only breed in the areas they occupy

14. Sympatric Sepciation Amphilophus zaliosus Amphilophus citrinellus

15. Polyploidy More than 2 sets of chromosomes

17. Polyploidy in the Evening Primrose • Oenothera lamarckiana • 14 chromosomes • Oenotheragigas • 28 chromosomes

18. Macroevolution • Evolution that results in new species

19. Evolution • Microevolution • Evolutionary changes within a gene pool of a population • Small changes in the organisms • Macroevolution • Evolutionary changes are significant enough to produce new species • Microevolutionary changes eventually result in macroevolution

20. Adaptive Radiation

21. Phylogenetic Tree

22. Convergent Evolution • Whales are mammals • Evolved a fish like body

23. Divergent Evolution Mammal Reptile Bird 23

24. Classifying Living Things • In science, a two-name or binomial nomenclature is used for each species. • The first name designates the genus, or group of closely related organisms, that the species is a member of. • The second name is specific to the species. 24

25. Carl Linnaeus 1707-1778 • Father of taxonomy • Binomial nomenclature

26. Felisdomestica

27. Linnaean System of Classification Kingdom (Animalia) Phylum (Chordata) Class (Mammalia) Order (Carnivora) Family (Felidae) Genus (Felis) Species (Felisdomestica) Figure 18.11

28. Cladogram Derived Ancestral

29. hagfish lizard deer lion seal Figure 18.14  A Simple Cladogram aquatic habitat carnivorous feeding mammary glands Derivedcharacters tetrapod structure 29

30. The End

31. Western meadowlark & eastern