George,
Well, due to a recent encounter with the comet Swift-Tuttle (plus backfire
from Shoemacher-Levy-9), previously frozen alien viruses came to fall to
Earth - in-particular your garden. Here, their half-trifid genomes came
into play, and they started to attack the nearest carnivorous plants.
First generation "mutations" appear as merely that - extra large, or
crinkled leaves. Beware of the second generation - when the flytraps gain
true locomotion, and you have to build a fence to keep them in (and make
sure the dog or cat doesn't accidently venture into the garden).
3rd generation, well you've seen "Species".... :-)
Oh dear, another late night at work gets to me!
Richard