Problem 5 - genetic and environmental influences

Question 1

reasons why variation in characteristics persist (2)

Answer 1

1) Fluctuating optimum: ideal level of a characteristic shifts according to any changes in environment
2) Frequency dependence: there might never be a single ideal level of characteristic, but rather an ideal balance of different levels of characteristics

Question 2

comparing similarities between identical twins and between fraternal twins

Answer 2

-‘extra’ similarity of identical twins beyond that of fraternal twins should be due to additional genetic variation

Question 3

additive genetic effects

Answer 3

-combined effect of genes can be estimated by simply adding together their separate effects

Question 4

non-additive genetic effects

Answer 4

-combined effects are different from what you would expect