Just for clarity, this map doesn’t show all Amtrak stations. The cities pictured are just the big ones on the routes

Some of us are biology geeks who know how computers work too.

There are some flaws in the common understanding of survival of the fittest, but I will ignore that for now.

Poison is usually energy intensive to make, so there is an investment from the mushroom in being harder to eat. If there is not a strong pressure from predators, or the mushroom adopts a different strategy like making tons of fruiting bodies (mushrooms), it might not be worth the cost to make the poison.

Finally, poison doesn’t automatically win the evolutionary race. We eat tons of stuff that the plant/mushroom intended to be a deterrent or poison (why are peppers spicy?).