1. Happy (198 th ) birthday Chucky D.!!!

2. Mutations are random Luria & Delbrück experiment (1943)

3. Mutations are random Joshua & Esther Lederberg (1952) Replica plating

4. Phenotypic effect of mutations Ranges from neutral to substantial Antennapedia

5. Distribution of mutational effects upon fitness Theoretical prediction, only now some data… proportion deleteriousbeneficial lethalneutral

6. Natural selection Definition: “Any consistent difference in fitness… among phenotypically different biological entities” (Futuyma, p.349) Requirement: variation in traits that effect fitness Selection always equal to evolution? Contrasts with drift – chance rise of genotypes More than just success of individuals Cause & effect… (Gould & Lewontin, 1979)

7. Levels of selection Group selection –Wynne-Edwards: self-regulation and restraint of individuals (“ensure survival of the species”) –Related to “balance of nature” in ecology –Williams: Only individual level benefits Species selection Genic selection –Dawkins: The Selfish Gene (1989)

8. What is adaptation? Noun vs. verb (vs. acclimation) –Noun: “…[A] feature is an adaptation for some function if it has become prevalent or is maintained in a population… because of natural selection for that function” (Futuyma, p.355) –“… the good fit of organisms to their environment” (Gould & Lewontin, 1979) Preadaptation… Exaptation… Traits can be non-adaptive

9. What adaptation is not… Necessary Perfect Progress Harmonious Moral

10. Looking forward… Assignment: Revised plan from each group (1-2 pages) Microbiology review sessions: 2/15, 6 pm – Brock 1, 2, 5 (General micro & metabolism) 2/20, 6 pm – Brock 6, 9, 12, 13 (Microbial growth, basic virology, overview of bacterial & archaeal diversity) Special guest lecture: 2/22, 6 pm – Daniel Segrè, “Origin of biological networks” *pizza & beer will be provided*