Still just a bunch of chemical reactions?<quoted text>
Life isn't a computer. Do not confuse the two. Life follows algorithms, not math. We use the numbers to describe things, the things are not bound by those numbers. "Odds" is simply stating that we cannot predict all the variables and calculate all the factors, everything is cause and effect, we just don't know all the causes, and intelligent people don't fill in causes with guesses, just like intelligent people know that certain chemical reactions will always occur in specific instances, and that's what you are. All life is a bunch of chemical reactions, which produce the effect we call life.
Describe and define then the evolution of sentience (reasoning, the sense of self, personality, thinking, etc). I would contend that sentience is very much more than just a bunch of chemical reactions.