Lecture 4: Natural selection

Question 1

natural selection

Answer 1

any consistent differences in fitness among different classes of biological entities

Question 2

fitness

Answer 2

the number of offspring an individual leaves to the next generation

Question 3

conditions for evolution by natural selection

Answer 3

reproduction, variation, inheritance, differential success

Question 4

positive selection

Answer 4

selection for an allele that increases fitness

Question 5

Effect of positive selection on genetic variation

Answer 5

tends to reduce genetic variation

Question 6

selection coefficient

Answer 6

a measure of differences in relative fitness among genotypes

Question 7

effect of selection on evolution

Answer 7

stronger selection leads to faster evolution

Question 8

linkage disequilibrium

Answer 8

a measure of non random associations between alleles at different loci. high LD just after a sweep

Question 9

overdominance

Answer 9

occurs when heterozygote has a higher fitness than either homozygote

Question 10

negative frequency dependent selection

Answer 10

the fitness of an allele decreases as it becomes more common (rarity is favored)