[tstactplsignore]

The premise is highly unsound. This study is talking about somatic mutations, which can only be harmful to an organism. Why? Because they can be beneficial to an individual selfish somatic cell, which is what we can cancer. In other words, when a somatic mutation is succesful, it spreads and becomes cancer. And of it doesn't spread, it can't have a serious impact on the phenotype of an entire organism.

So, the mutations discussed in the article have nothing to do with evolution, because they are somatic, and not passed on to offsprig. But even if smoking caused germ cell line mutations, it's also important to note that "highly evolved" is a mostly nonsensical phrase that has no real meaning, and there is absolutely no guarantee that any individual germ line mutations would confer a selective advantage to the off-spring- in fact, the majority of the time, specific mutations are neutral or harmful. Thus, even if smoking did increase the mutation rate in the germ line of a smoker, any given smoker kid would probably just have more problems than benefits. And because mutation rate is (maybe this is somewhat controversial) a phenotype that can and has evolved into itself, changing it artificially through smoking would likely result in a net reduction in "evolvability" as it has been called. Anyways these are all long term (and I mean LONG) population level effects and have nothing to do with individuals being "more evolved".

Just trying to make the point that the original assumption was three times removed from a sound understanding of evolution and showed some pretty big misconceptions.

[adrianN]

"Can only be harmful" is pretty strong. You could have a set of mutations in a T-Cell for example that makes it super good at killing all forms of cancer.

[vibrio]

You could get a 'super T cell' that behaves just as you want, or as is empirically observed, mutations would more commonly lead to leukemia. There is a phenomenon call somatic hypermuatation, that as T-cell respond to antigens, they 'get sloppy' in coding their DNA to optimize the response. It' has also been linked to blood cancers, so it is a risky approach, like many aspects of immunity.

[adrianN]

Of course almost all mutations won't be beneficial (this is also true of germline mutations). But "can only be harmful" seems to imply that beneficial mutations are impossible.

[vibrio]

agreed. sort of my point: some changes can be beneficial, but the process is very risky and the cell goes through great measures to minimize any sequence changes. some viruses are sloppy on purpose, as they have tens or hundreds of thousands of offspring, so trial and error is acceptable.

[tstactplsignore]

I'm still skeptical- I doubt a single T-cell can have anything but a ever so slight statistical inpact on the phenotype of an entire organism, and there is no selective process to keep that mutation around, so it cannot last long in the body, either.