if there is enough natural selection in individuals, the population as a whole begins to change. for example: mutations in one singular butterfly that look like eye balls scare away it’s predators and allow it to survive. this butterfly reproduces and the eyeball-wing-gene is distributed throughout its offspring. since these offspring are more likely to survive because of their mutations, the population as a whole will eventually consist of all, or almost all, butterflies with this eyeball-wing-gene.
