Hummingbirds use their long, narrow beaks to get nectar and insects from flowers. Scientists studied a group of hummingbirds in an area for a number of years. They collected data on the beak length of the population. Over the years, they noticed that the beaks were getting longer. Explain what could have been happening to the hummingbirds that made this happen. Also explain what could have been going on in the environment that made this happen.