I've reached my evolutionary limit...

So I'm reading a thread on evolution and a commenter says:

A species never gets any smarter than it need to be. Many years ago, I used to say much the same thing re evolution, but I phrased it as "an organism is likely to have little incentive to evolve much past the point at which it can consistently catch its natural prey".  I used as an example "Consider that Norske fishermen have evolved, over the years, to the point at which they are very good at consistently catching cod-fish."

I"m Irish, my natural prey is a potato.