If organisms a and b both possess wings and are the only extant organisms that possess wings, then we can hypothesise that the current generation of flight organisms are the descendants of a, b, or both a and b, and that the wing trait first originated in these two organisms.
Since the trait for flight first evolved in a and b, it must have been carried forward into the future generations of species that must have evolved by various evolutionary processes like speciation, acting on a and b.
