BIOS E-127 – Prior theme music: “Evolutionary speculation constitutes a kind of metascience, which has the same intellectual fascination for some biologists that metaphysical speculation possessed for some mediaeval scholastics. It can be considered a relatively harmless habit, like eating peanuts, unless it assumes the form of an obsession; then it becomes a vice” (Stanier, 1970)
Mutations are random Luria & Delbrück experiment (1943)
Mutations are random Joshua & Esther Lederberg (1952)
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)
How study adaptations? A. B. vs.
How study adaptations?
Linnaean classification Two major characteristics KingdomAnimalia PhylumChordata ClassMammalia OrderPrimates FamilyHominidae Genus Homo Speciessapiens
Tree of Life: primary divisions
Tree of Life: three “domains” Based on 16S rRNA (Woese, 1987):
Tree of Life: three “domains” Based on 16S rRNA (Pace, 1997):
Tree basics: meaning
Tree basics: rotation
Tree basics: shape
Tree basics: lengths, unrooted cladograms vs. phylograms
Tree basics: character change
Key phylogenetic terms
Monday (9/29): Phylogeny and horizontal gene transfer p.s.- No office hours from 4-5 pm this week.
Upcoming talks in microbial evolution… Tuesday, 9/23 Uri Alon (Weizmann Institute of Science) “Design principles of bacterial gene circuits" HMS Microbiology and Molecular Genetics Seminar Series Warren Alpert, Room 341 (Longwood) 12:30 pm Wednesday, 9/24 Marx & Girguis labs open house 6:30 – 8 pm, 3081 Biolabs All are welcome to come enjoy a beer and snacks and learn about work in our labs…