meat is murder?

My little sister told me over the weekend that she is now a vegetarian. That struck me as shocking at first, and now I’m starting to question myself. Plants and animals alike are an important part of the environment. So should I, as an environmentalist, not eat animals? I took some time over break to mull this over a bit and here’s what I came up with.
Feeding off of Mr. Charles Darwin, we are the fittest being on Earth and we should exemplify our superiority by surviving. Me must eat, sleep, and procreate. Healthy eating includes proteins and other things found in animal meat. That is why we eat them, to stay healthy, full, and fat; i.e. be the “fittest” animals alive. Since we too are part of this world, we should be allowed to eat other animals without distress, and continue our survival.
My second theory was that we should all be vegetarians. Mankind has evolved so to the point where we can artificially generate what we gain from eating meat. We don’t need to barbarically slaughter animals and consume their flesh, and fashion their skin to our liking. But we do. And we like doing it. The chief reason we eat it is because of taste. Our society no longer needs to worry about eating to survive; we are beyond that phase in evolution. In fact, most of the nation is worrying about eating too much to survive. We are humans, we are selfish, and we are pigs. We eat for pleasure and meat is our lure.