Don't be so sure! Humans have had more genetic change in the last 50,000 years than in the 1M before that. One train of thought is, civilization put entirely n

Don't be so sure! Humans have had more genetic change in the last 50,000 years than in the 1M before that. One train of thought is, civilization put entirely new pressures on us and we adapted. Smoke has been with us for a very long time. It's almost certain that we have some adaptation to it.