Science doesn't really support such an idea as of yet. I'd be willing to see any supporting evidence, but until then i'm not going to subscribe to a notion of karma any more than I will of standardized morality, or gods.
From what I've observed of the universe, not only is karma unsupported, it seems unnatural. Things are harmed for the purpose of sustaining life in the natural world constantly, it seems selfish but really it's just how life works. It cannot exist without taking from something else for it's own gain.
our whole universe is a world of utterly destructive forced of incredible power that consume, crush, burn or destroy other things, and even themselves. It's destruction that creates the world, it's chaos that the universe is born of, and it's selfishness that creates, and sustains life around us. Morals don't have a role in the universe except among humanity, and they are killing our world off slowly.