1. You have a population of birds with long tails. The mean tail length is 20cm. Now imagine we select a group of birds to breed with a mean tail length of 15cm. If the heritability of tail length is 0.58, what should the mean length of offspring tails be?

2. Birds live on a single island and eat seeds. A bird's beak morphology affects how efficiently it can eat. During a rainy year, birds with smaller beaks do better. Birds with larger beaks take too much time to eat each seed.

Beak depth of the population is 10mm. Beak depth of the selected parents is 9.5mm. And h² of beak depth is 0.9

What is the predicted beak depth of the offspring?