"an organism develops a trait optimized for a specific use, but then the trait gets hijacked for a completely different function" (p154).
Essentially, Johnson is suggesting that ideas come from the a change to a trait that was originally exhibited. I think a controversial word here is "hijacked." I believe that traits are shared and understood but new ones rise based on what is favored or how it is seen that a new idea or trait can be used - the trait is not necessarily stolen, but rather used as a basis for a which in which a new trait can have a new function. This relates a lot to my Evolution course I took. We often discussed how ancestors have shared traits however on a phylogenetic tree, it is seen that new traits arise from those older ones and evolution or change over time among populations is seen. Thus, relating back to the real world, I think sharing ideas give way for new ideas to be proposed and used in a different way. Overall, I thought relating this chapter to the ideas of evolution was a great way to describe how new altered ideas arise from ones previously seen. Like Johnson states,
"exaptations help us explore the new possibilities that lurk behind those doors" (p156).
Therefore, new ideas arise from ones that previously exist, but these new ideas are used in a different way than the original.