Considering the species, there must to be at least some genetic drift -- variability -- in a any given population of N. macrophylla, just as in other Nepenthes. N. hamata is a good example, where I have seen a good variety of pitcher shape, varying development of its peristome, color, hirsuteness, or even lack thereof. So far as I know, few are suggesting that current varieties on the market are anything but N. hamata; and I am certain that even individual cultivation plays a role . . .