week 5

Question 1

modes of selection

Answer 1

• directional selection
• stabilising selection
• purifying selection
• frequency-dependant selection

Question 2

directional selection

Answer 2

selection that changes the average value of a trait, because the highest average reproductive success is found in individuals above the current average

Question 3

stabilising selection

Answer 3

in a quantitative trait, selection that leaves the average of the trait the same because individuals with the average value have higher average reproductive than those above or below

Question 4

purifying selection

Answer 4

in a gene that does something useful, the conservation of that gene the same over evolutionary time because any mutation makes it work worse and hence gets weeded out

Question 5

frequency-dependent selection

Answer 5

selection that results in a mix of two-types or variants, because each variant produces higher average reproductive success when rare and lower once common