[gumpzilla]

Is the problem you're mentioning the lack of appropriately circularly polarized light from neutron star sources? I don't think that's a big deal. Circularly polarized light isn't all that tough a thing to come by. All you need is different indices of refraction for the two different linear polarizations and you're in business. Plenty of natural crystals have this property. My knowledge of astronomy/cosmology is disgracefully poor, so I'm not sure how realistic this scenario is, but birefringence is pretty common and it wouldn't surprise me to find that one could cook up a reasonable scenario allowing it before life. There was also the suggestion that light observed from some nebulae appeared to be strongly circularly polarized.

And I was also not referring to this theory directly, which seems to be keen on the notion that the asymmetry came in before life. I'll have to dig out my copy of Jackson and look at the atmosphere/circular polarization bit, but if slightly increased absorption leads to an unfortunately high mutation rate, you could see wrong-handed DNA die out because it isn't a faithful enough replicator, possibly. (Yes, I am talking out my ass.)