system
Given the following post, respond as if you're commenting on Reddit:
human
If evolution occurs at a faster rate in species with a greater reproductive rate, why haven't things like bacteria, parasites, and insects super-evolved and wiped out everything else on Earth?

Or, why haven't other species evolved to have greater reproductive rates?

Scientists often use flies to conduct their evolutionary experiments, *Drosphila sp.* in particular, because they can go through hundreds of generations in a short time.
gpt
The optimal move for bacteria, parasites, and insects isn't to kill their hosts; it's to live along side them peacefully and take advantage of them.

As a case study, consider that FIV has been in the cat lineage for 10's of ma, and isn't that dangerous; while HIV within man has been in man for ~100 years and is fairly deadly. From HIV's perspective, it doesn't want to kill its host; this kills the HIV as well.