2. How might this population suddenly increase? How might this affect the ecosystem? (artic fox / artic tundra)

it can suddenly increase when more and more people have babies and the infant rate goes up. and how it might affect the ecosystem is the pollution that people give off.

if the type of the food available changes, then the frequency of beak types will change, because birds with beaks more suited to the available food will be more successful over time.