What Biology Tells Us About Aliens

Things that fit together according to the scientific paradigm are what I use to speculate on the design of intelligent aliens. Living things need an atmosphere. A planet needs a certain minimal amount of gravity to maintain an atmosphere. Intelligent creatures need a large brain. The carrying capacity of a skeleton increases with the square of the linear size of an animal. The weight it must carry increases with the cube of the linear distance. A brain needs to be fairly large so between the gravity and the necessity for a large brain, alien size needs to be near where we are -- too small and not enough brain. Too big and too much weight for bones. They likely have lungs due to the same sort of thing. The necessity for oxygen increases with the cube, the area to transport oxygen increases with the square. They need to gather oxygen from a surface area larger than their ordinary surface area allows. Evolution conserves across different time scales. Animals like us have coverin...