In this chapter it was mentioned that the idea of 'exaptation' is central to the idea that animals develop certain adaptions and physical prowess for a specific use. Following that point, it is mentioned that after years of research on a specified animal, the function that we had thought the animal had grown a certain adaption for was for something else. For example, for decades we thought that birds had developed feathers for warmth, but it turns out that a birds feathers have many more functions that we had thought in the first place, like air regulation and flight stimulation. What I got from this idea brought up in chapter 6 was it may be possible that birds could have used this unknown trait for the specified uses stated for many years, we just hadn't known about it. All in all, I feel that certain theories are solely based off of human idea, not biological evidence.