DIRECTIONS: Why finish a medicine that kills bacteria, even after you feel better? Read the box, then fill in the table.
They are not all the same.
A few million bacteria are not identical copies. A handful of them are, by luck, a bit tougher against the medicine than the rest.
Day one to three, the medicine kills the weak ones — which is most of them — and you feel better. You feel better precisely because the easy ones are gone. The tough handful are still there.
Stop now and those survivors have the place to themselves, with no competition and nothing killing them. Every one of their descendants is tough. You have not just failed to finish. You have run a competition and let the winners breed.
Day
Easy ones left
Tough ones left
How you feel
Before any medicine
Day 3, still taking it
Day 6, if you stopped at 3
Finish the Bottle — The Same Idea, Bigger
What keeps a body working · Page 2 of 2
DIRECTIONS: Medicines that kill bacteria do nothing to a virus. A cold is a virus.
Explain, in your own words, why feeling better is a bad reason to stop.
Somebody takes this kind of medicine for a cold, which is a virus. Say why it will not help — and why it is worse than merely useless.
This is natural selection, in a week, in one person. Say what is doing the selecting here, and what the equivalent is for an animal in the wild.