That's the beauty of it, and it's also what puts a lot of people off [the 'it seems to complex', thing]. All of this, out of chemical reactions becoming little beautiful and special groups of chemicals that could eventually self replicate. Then, them being able to THRIVE thanks to natural selection, and be wiped out because of it, too, and filling the oceans with cells that now joined together to form multicellular organism that would then change according to genetic mutations and their ability to survive, eventually becoming trilobites, fish, dinosaurs, mammals, amphibians and more due to RANDOM changes that either killed creatures or enabled them to survive. Look at your eyes, they're amazing things, aren't they? Now, think of a mantis shrimp. You can (probably) see red, green and blue light, but a mantish shrimp's eyes could see things that you couldn't even imagine due to their eyes having 12-16 photoreceptors, whilst you have 3. Once again, with eyes, look at a deer's eyes, a bat's eyes, and a goat's eyes, all of them are different because they're there according to the needs of the animal and it's ancestors. I don't have much time to write now, and can't really do it justice, sorry.