eli5: Why do some tiny animals contain enough venom to kill thousands of humans, isn’t that just overkill?

Question

eli5: Why do some tiny animals contain enough venom to kill thousands of humans, isn’t that just overkill?

In: 356

Answer 1

There’s no threshold in nature that says killing humans is all you ever need to do so there’s no need to do more. The animal produces a toxin. It produces a certain amount of toxin. That might be enough to kill thousands of people or just enough to kill one. There’s no conveyor belt where these creatures are being assembled where someone looks at a checklist and says, “Nope, doesn’t need all that venom.”

It’s evolution, and assuming evolution happens for a reason is missing the point of evolution.