Sorry, I'm not a subscriber so I can't access it...but I recall reading something about this in a recent astro magazine article (S&T?).
If there are planets around such stars that harbour life they have a lot longer to evolve than we had too! Whilst our star is destined to die in the future taking all of us with it, these things will still be hanging around when all the big guys have gone bust. So if your planet is orbiting one of these stars and it was created at the same time as ours, but life has not begun to evolve yet...you still have tens of billions of years to get it right (even after our Sun has gone "planetary").
