Some sort of selection definitely happens. The first stars were huge and simple, with only hygrogen and helium. They seem to be evolving toward high metallicity and medium size.

But what sort of selection is this? Evolution requires, roughly, reproduction and inherited variation with selection. I could imagine that we might see something like this in a stellar life cycle where stars go supernova, scatter gas clouds, and new stars form to go supernova and form even more new stars, but as far as I know, this is not anything we see (and wouldn't work with dark matter, anti-life antibodies, or galaxy-scale organisms), inasmuch as stellar creation is shutting down (I've read this in various places, most recently http://lesswrong.com/lw/i2i/link_cosmological_infancy/ ) and I'm not clear what sort of variation could be inherited there either.