ABSTRACT
In evolution and biology, previously existing structures and mechanisms are constantly being reused for new purposes. For example, fins evolved into limbs, which in turn became wings, while scales were modified into feathers. Reusing structures to solve new problems occurs not only evolutionarily, but also developmentally, as we grow up. For example, reading seems to depend on previously existing brain circuitry that is coopted for this function as we learn to read.
