The universe is composed of a limited number of materials and elements. When some of those are combined, they create conscious life. Simple as that.

I think you guys are viewing consciousness as something very advanced, which i do not see it as. I think consciousness is just like a computer. Your eyes, ears, and touch are just things that send electrical input signals to your brain. Based on those signals your brain sends more electrical signals to other parts of your body, creating a reaction.

That simple input/reaction(output) can be applied to anything we do, whether it is building a bridge or deciding what to write in a post.