Opinions/theories on consciousness?

I want to hear thoughts on consciousness. I have my own theories (on the matter of what it is and how it came about) and am quite resolute in that I think they are correct. But I've engaged enough with my own opinions for a lifetime, I want to hear others. Everyone seems to have a unique and interesting take on the matter. Is it's existence purely conceptual, or does it have some physical manifestation? Did it come about via evolution? How? If not, then how so? Is it something that exists only in humans, or do other animals have different levels of consciousness? Biological byproduct or an inherent force of the universe? If so, how did we harness it? Give me your thoughts. I may respond in kind if I feel so inclined.