From over there on Pharyngula:
God Design Workshop Audience: Ooh! Get you!
God: Get me indeed. Let me take you through the specs of this ultimate species. As you can see it's bipedal - we did toy with six legs but the economics of keeping the females in shoes was too horrific to contemplate. These things here at the ends of the arms are called "opposable thumbs". Boffins in the lab came up with them and, if they work out as we think they will, then we'll roll out upgrades to the other species, probably starting with the caterpillars.
Audience Member: Sorry, God, may I? These whatever-they-are thumbs; what are they for?
God: Opposable. They have many uses but one I'm particularly fond of is this ... hang on ... there, it's called a sock puppet and do you see how I can form the mouth?
God: Okay, back to the human. Trichromatic vision, two eyes for depth perception, air breathing so it can fit in and manipulate the planet more easily. Notice the large skull; we've got the biggest and latest brain model to go in there. Here in the throat we've added the capability for speech to develop too. No more grunting and pointing and hitting! Any questions?
Audience Member: I can't see a carapace and the exposed flesh looks quite soft. I assume the bones are strengthened to prevent crushing or snapping and there's protection for the organs too.
God: No. Anything else?
4 minutes ago