Finches developed special beaks that help them eat either insects or seeds, depending on which is more plentiful in their area.
Why is this a good example of an adaptive function? There is a lot of variation in beak type. Different beak types make finches less likely to be eaten by a predator. Finches learned to communicate about food options. Different beak types help the finches survive in their environment.
It is a good adaptive function because if Finches didn't have there special shaped/sized beaks they wouldn't be able to eat, and if they couldn't eat they would starve and die. If all of the Finches did die there is a posibilty that alot of insects would take over. (sorry if this is a stupid answer and if you don't use it it's fine im kind of stupid)
