Consider the trilobites. If there had been a trilobite-Friendly AI using CEV, invincible articulated shells would comb carpets of wet muck with the highest nutrient density possible within the laws of physics, across worlds orbiting every star in the sky. If there had been a trilobite-engineered AI going by 100% satisfaction of all historical trilobites, then trilobites would live long, healthy lives in a safe environment of adequate size, and the cambrian explosion (or something like it) would have proceeded without them.
https://www.lesswrong.com/posts/cmrtpfG7hGEL9Zh9f/the-scourge-of-perverse-mindedness?commentId=jo7q3GqYFzhPWhaRA