[Sforlips]

1) even if their environment was very similar, it wasn't identical, if only because they interacted with each other. As you probably know, living system are roughly chaotic (except that, formally, chaotic systems are strictly deterministic, whereas determinism in the real world is debatable), and a tiny difference at one time point can have drastic consequences later on.

2) identical genes can lead to different phenotypes. Take the example of handedness. There is a dominant allele for right handedness and a recessive allele for random handedness. The people with two random genes have 0.5 chances of being right handed, and 0.5 chances to be left handed or ambidextrous.

The same gene also determines if the hairwhorl turns clockwise or counter-clockwise, with the same behaviour. The dominant allele mean clockwise, and the recessive one is random. AFAIK, in the random case, handedness and whorl direction are independant.

I don't think that your example is a good case for dualism.

Edit: Were you trolling?