I'm bookmarking it for discussion and future reference, since (as my last post should suggest) I am in no condition to peruse a lengthy formal paper at the moment.
The opening of the abstract immediately intrigues me, however (and not just because I've been reading too much Gamma World material):
An evolutionary capacitor buffers genotypic variation under normal conditions, thereby promoting the accumulation of hidden polymorphism. But it occasionally fails, thereby revealing this variation phenotypically.
If I'm interpreting this correctly, this suggests a physical mechanism for punctuated equilibrium, as well as suggesting how the usual wisdom that "random mutations should be automatically lethal 99% of the time".
I don't know how the biochemists and geneticists in the audience will react to this, but as a systems scientist, it makes perfect sense to me. Complex systems often develop regulator mechanisms as an emergent behavior.