1. Bio 7: General Biology II Evolutionary, Organismal, & Ecological Biology Dr. Diane Livio liviodl@lamission.edu myetudes.org/portal MW 2:30-4:30 (CMS 229) TTh 3:30-4:30 (CMS 106)

2. Majors course – rigorous and challenging, designed to be rewarding Student responsibilities Review the syllabus Check Etudes regularly About this course

3. What is expected of you? What do you expect of me? Or your class mates? Of the course? First module on Etudes has help!  “Learn How You Learn” www.vark-learn.com Expectations & Goals

4. Evolutionary Processes "Nothing in biology makes sense except in the light of evolution" - Theodosius Dobzhansky

5. Scientific Theory Def: a proposed explanation for a very general class of phenomena, supported by a large body of evidence Possesses both pattern and process components

6. Theory of Evolution On the Origin of Species (1859) All life evolved gradually from one primitive species [lived 3.5 bya] –Split off into many diverse species over time –Mainly by natural selection

7. Pattern of Evolution Descent with modification –Inherited characteristics in a population of a species change over time –Sometimes population changes over time to form a new species –Newer species descend from older species

8. Macroevolution Pattern of evolution over large scales –Larger than the species level –Over geologic time scale How old is the Earth? How old is life?

9. Earth’s Early History Estimates of Age of Earth/Solar System -- Current estimate: 4.54 by Oceans formed by 3.8 bya No O 2, much solar radiation

10. Life – 3.6 to 3.8 bya Oldest fossils: 3.5 by Most history of “higher” organisms in most recent 500 million years…

11. Macro- vs Micro-

12. Process of Evolution Microevolution: the change in allele frequencies in a population over time Population: a group of individuals of one species living in a particular place

13. DNA Genetic info – heritable Genes: code for proteins to make and maintain organisms Allele: form of a gene

14. GENOME CHROMOSOMES GENOTYPE vs PHENOTYPE NUCLEOTIDES

15. Process of Evolution Microevolution: the change in allele frequencies in a population over time Mechanisms of Evolution: 1.Mutation 2.Genetic Drift 3.Gene Flow 4.Natural Selection

16. Mutation in DNA Def: change to the nucleotide bases (adds variation to the population)

17. Mutation = Source of DNA Variation DNA Replication = Potential MISTAKES

18. Genetic Drift Def: any change in allele frequencies in a population that is due to chance –Random with respect to fitness

19. More pronounced in small populations Drifting allele frequency could lead to loss of allele or fixation (100% frequency) Fig. 23.4

20. Genetic Drift - how it occurs: Genetic bottleneck – sudden reduction in # of alleles in a population

21. Conservation biologists manage “gene pool” of species with small population sizes to prevent loss of alleles through drift.

22. Genetic Drift - how it occurs: Founder’s effect – change occurs when a new population is established –Small subset does not represent allele frequencies of source population

23. Gene Flow Def: change in allele frequency due to migration between populations

24. Gene Flow: movement of alleles from one population to another –Tends to make one or both populations look more like the other

26. Charles Darwin: The Origin of Species (1859) Identified natural selection as the major mechanism of adaptive evolution Much focus on survival aspect of reproduction  “survival of the fittest”

27. Adaptive Evolution Adaptation = a heritable trait that increases an individual’s ability to produce offspring (its fitness) in a particular environment relative to individuals lacking the trait

28. Natural Selection Process by which heritable variation leads to differential success in survival and reproduction Differential reproductive success can result from differences in survival, fecundity, and mating success.

30. Artificial selection – deliberate manipulation by humans

31. Summary Natural selection adapts a population to its environment. Selection operates on individuals. Evolution occurs in populations and species. Other mechanisms of evolution: mutation, drift, gene flow.

32. Speciation Species: “an evolutionarily independent population or group of populations” –Reproductive compatibility –Similar physical appearance –Shared, unique genetic history Allopatric vs sympatric speciation –Physically separated populations vs “living together”