How does an animal adapt to things if the animal that experienced it died?

Question

For example killing cockroaches makes them harder to kill or killing them with baygon makes them adapt if they’re already dead?

In: Biology

Answer 1

The roaches you kill don’t evolve, but you didn’t kill them all. Some of them only got hit with a little bit of poison, and while most of those died too some of them didn’t. The ones that were slightly less sensitive to the poison are more likely to live, which lets them have babies.

Those babies, like their parents, are slightly less sensitive to that poison, so need to get hit with a little more before they die. Repeat this over many generations (where only the more poison-resistant ones survive) and you end up with a population that has evolved resistance to that poison.