Download presentation
Presentation is loading. Please wait.
1
BIOS E-127 10.09.13 “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)
2
Are mutations random & independent of selection? Luria & Delbrück experiment (1943)
3
Joshua & Esther Lederberg (1952) “Replica plating” Are mutations random & independent of selection?
4
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. p.592)
5
Points re: “Spandrels” Spandrels (p.581) Dr. Pangloss (p.583) First target? (p.583) Natural selection can’t drive extinction (p.584) Only brake upon perfection? (p.585) Tyrannosaurus? (p.587) Bluebirds? (p.588) G&L other possibilities? (p.590) “Baupläne”? (p.593) In ecology too…
6
How study adaptations? A. B. vs.
7
How study adaptations?
8
Microbial systematics Formerly Pseudomonas (partial list): Ralstonia, Burkholderia, Hydrogenophaga, Sphingomonas, Methylobacterium, Cellvibrio, Xanthomonas, Acidovorax, Hydrogenophillus, Brevundimonas, Pandoraea
9
16S rRNA as phylogenetic marker Why a good molecule? 70S 30S 50S
10
Tree of Life: three “domains” Based on 16S rRNA (Woese, 1987):
11
Tree of Life: three “domains” Based on 16S rRNA (Pace, 1997):
12
Bacteria & Archaeal: all genomes as of 12 Feb., 2010 (Lee, Robinson & Marx, in prep)
13
Tree basics: meaning
14
Tree basics: rotation
15
Tree basics: shape
16
Tree basics: character change
17
Monday (9/20): Phylogeny & horizontal gene transfer & comment…
Similar presentations
© 2025 SlidePlayer.com. Inc.
All rights reserved.