I agree. The example with Nicotine intake having a somewhat positive effect on the children feels too wild at the money. Think of all the kids of the 60th and 70th. They must be immune to most toxins ;). Yes I take this example to the extreme. I also feel that this could maybe contradict what we learned from evolution theory. Why would it take so long for a given treat to establish itself. Maybe I mix too much into one bag after reading this one article.

>I also feel that this could maybe contradict what we learned from evolution theory.

It doesn't, but the article doesn't go into this detail, so people unfamiliar with the field wouldn't understand why. The keyword is epigenetics. I.e. how certain genes become activated or deactivated through behaviour and/or environmental influences. But the DNA sequence itself remains unaltered. So no evolution necessary. There are basically a bunch of molecules than sit on top of your DNA that regulate gene expression. They don't just tell a cell to behave like a skin cell or a brain cell, they also regulate the entire cellular metabolism. The discovery that male sperm can also transmit this epigenetic information to offspring is relatively new, but now that we know that, it makes total sense that these gene-expression-modifying behaviours in fathers could affect their children. After all, they simply get to start with a good (or bad) bunch of epigenetic markers. They will not persist across many generations though, so it has no real long term effect on evolution. It may even be an evolved mechanism that allows organisms to respond to environmental changes on timeframes that would be prohibited by evolution.

Speaking mostly from personal experience here, if a kid gets a suped-up liver from their dad's smoking habits, cool. But how many kids fathers stopped smoking when the kid was born? My point, the father's smoking habits may have passed down a strong liver but his continued use damaged the child's lungs and possibly more.

These mechanisms of epigenetic inheritance or whatever need much more study. It is far too early to draw any conclusions other than we need to keep researching.

If true, I suppose there is also a opportunity cost involved. Meaning selecting for better coping with nicotine, does not help selecting for smarter offspring and maybe even preventing that. So it might be somewhat positive but at a cost unknown.

Also there are the very known costs of nicotine damaging sperms, or of course being in literal smoke as a child (or adult) and deal with those real effects.

  >Think of all the kids of the 60th and 70th. They must be immune to most toxins ;).

But seriously though, "immune" is a humorous exaggeration, but I'm not sure we have data to rule out the idea that this cohort has increased tolerance to some environmental toxins.

So it's possible the level of harm we see today is already "post-" this protective effect, if any.

> They must be immune to most toxins ;)

Allergies and cancer are way up.

There’s multiple causes behind those, this is almost certainly one.