Feathers did not evolve originally as a flight mechanism. Feathers are used for thermoregulation. However, as a species grew more feathers, for thermoregulation, they became sufficient at one point to enable the bird to fly. Latent potential enables innovations in functions. The extra material becomes available to construct evolutionary novelties.
Redundancy enables additional or new functions.
If an organism does not have sufficient variety in its own resources, it must be part of a larger ecosystem, with which it must have permeable boundaries. It is the number of possible connections that influence the ability to innovate through new combinations. Variety provides possibilities for innovations through new combinations. Human beings have self-awareness and ego. They work hard to preserve and enhance their identities.