“Okay, okay, I’ve got one. ‘Sloths.’”

“Sloths?”

“Sloths! They’ll live in trees and climb around and eat leaves.”

“That sounds pretty cute, evolution. But leaves aren’t all that nutritious, are they? How are they going to get enough energy to climb around?”

“Oh, I thought of that! They’ll supplement their diets with algae that they grow in their own fur. I even put special channels in their hairs to collect rainwater and keep the algae moist.”

“Huh, okay… but then what are the algae going to feed on?”

“Thought of that too. They’ll be fertilized by all the moths that also live in the sloth’s fur.”

“Wait, what? Seriously? Moths? And how are the moths going to reproduce? Their larvae need to eat something too, you know.”

“Yup, thought of that. Once a week, when the sloth needs to poop, it’ll climb down from the tree and poop on the ground. Then the moths can lay their eggs in the dung, and the larvae will eat that.”

“Okay, this is ridiculous. I mean, doesn’t climbing down to poop defeat the whole purpose of living in a tree? Won’t that make it stupidly easy for a jaguar or something to come along and eat them?”

“Well, yeah, that does happen. Kind of a lot, actually.”

“And?”

“Look, no system’s perfect.”

Source: Flickr / Scott Aaron / licensed under CC BY-NC-ND 2.0