That's definitely not obvious. I would agree that mutations due to smoking could be in majority harmful due to the chemical components and the high temperatures involved. Other than that, a mutation is a mutation, whether due to smoke, nuclear irradiation, high altitude, or chance. In all cases, they can be beneficial or harmful. The evolution process will then cause only the beneficial ones to perdure.
> The evolution process will then cause only the beneficial ones to perdure.
This isn't correct and is a common misconception about evolution. The process which does this is natural selection, and it only occurs through the organism being unable to reproduce as well as an organism with beneficial evolutionary changes.
With humans in the modern world, there is no natural selection because of state benefits that keep people alive and able to reproduce who would usually be unable to do so in a world without safety nets.
So in the modern world, any evolution in humanity - either positive or negative - will perdure. In effect we've ended the traditional form of evolution ages ago when we became civilized.
Another common misconception is that evolution can only occur via natural selection. Assortative mating[1] can still drive evolution for segments of the population, if not necessarily the whole population.
Also, the entire world does not have modern safety nets, not even close.
In USA, families on welfare benefits are also often the largest families. Being laid more is irrelevant if it does not result in a child. It's more reason as to why evolution is simply not a factor in the modern world.
Also, why do you say 'some'? It would stop all negative mutations, as all people are given the ability to reproduce. Your argument seems to be that people with negative mutations would not be attractive, but often they are attractive to others with negative mutations themselves. Or just people who no longer breed purely based on biological fitness - again because of modern civilization.
You have already said some people have larger families than others and these people have differences than others thus contradicting your premise where there is no longer evolution in human genes.
I never said there is no evolution? I said there is no longer a link between positive and negative traits and the ability of someone to reproduce. Whether someone has positive or negative mutations is no longer a factor in their survival, and so there is no natural selection of positive traits.
There is definitely no contradiction there. Genes will still evolve, but it will no longer be through a process of natural finding the most positive genes. Or I'd guess you could say that we will now evolve towards genes that enable the largest families. And the largest families are predominantly in poor suburbs. The actual environment is artificial though, as those families would not be able to survive on their own without support. Taken to an extreme, it would technically be 'evolution to destruction' by selecting for negative traits that make it impossible to survive outside of the safety net. Luckily we're nowhere near that kind of extreme.
It's funny how only one of those things you listed is a voluntary activity.
Anyway, by all means, continue smoking if you think it's going to give you some sort of superpowers or immunity that you can pass on to your progeny. Most likely it'll just give you a disease.