092007_EvolutionaryMechanisms3 - Intro to Organismal...

Info iconThis preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
9/20/2007 1 Intro to Organismal Biology 9/20/07 Announcements 2 1. Biology Department Survey Go to“External Links” on Blackboard Today’s class Evolutionary mechanisms continued: 1. Genetic drift (chance effects due to small pop. size) 2. Gene flow (migration) 3. Mutation (generating new variation) 4. Nonrandom mating 5. Natural selection (Relevant reading: Ch. 23, 51 pp.1129-1130) 3 Gene flow 4 Evolutionary Mechanisms Gene flow Population may gain or lose alleles Results from movement of fertile individuals (e.g., migration) or gametes (e.g., long- distance pollination) 5 Evolutionary mechanisms Mutation The only way to generate NEW alleles Mutation rates lower in plants & animals compared to bacteria and viruses. Only mutations in germ cells are passed to offspring. 6
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
9/20/2007 2 Evolutionary mechanisms: Mutation 1. Example: Point mutation e.g., AAATCGCCCG copied as: AAATCGCCC C Consequences? Could be harmless:
Background image of page 2
Image of page 3
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 04/17/2008 for the course BIOL 161 taught by Professor Vanroo during the Fall '08 term at Mass Colleges.

Page1 / 4

092007_EvolutionaryMechanisms3 - Intro to Organismal...

This preview shows document pages 1 - 3. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online