7. Natural Selection & Adaptation

Question 1

Fitness

Answer 1

genetic contribution of individuals to next generation Relative to others as a result of differences in viability and fertility (Darwin fitness *not absolute survival or offspring number)

Question 2

Selective advantage

Answer 2

the amount by which some individuals of a given genotype are better adapted to a given environment

Question 3

Adaptation

Answer 3

a trait that contributes to fitness by making an organism better able to survive or reproduce in a given environment

Question 4

How to study adaptation

Answer 4

• Monitor correlations of alleles or traits with environment over space and time
• Analyze genomic diversity (genes targeted by selection ought to show distinctive patterns)
  -Experimental manipulation in field and Lab

Question 5

Stabilizing Selection

Answer 5

Human birth weight: infant mortality is lowest at intermediate birth weight

Question 6

Directional Selection

Answer 6

Beak size in Galapagos Finches (as seed abundance decreased, the population fell), (as seeds became harder, the average beak size increased)

Question 7

Distributive Selection

Answer 7

Distributive Selection

Beak size in African finches- Distributive selection leads to trait divergence, in some cases it may lead to speciation, requires spatial heterogeneity or discrete resources

Question 8

Artifical Selection

Answer 8

• Selection by humans toward a goal
• Domesticated plants and animals
• Selection experiments in genetics
• Evolution of attenuated vaccines

Question 8

Artifical Selection

Answer 8

• Selection by humans toward a goal
• Domesticated plants and animals
• Selection experiments in genetics
• Evolution of attenuated vaccines