An international team reasoned there had to be a purpose for sleep. In one of the largest datasets ever collected, they believe they found two functions.
Consideration of the basic characteristics of nerve impulse propagation suggests that the speed of conduction in mammals is close to the maximum possible.
One area where very fast nerve conduction is vital is vision, more specifically, in keeping the eyes fixed on some object in the field of vision while in motion.
We transcend the strictly material forces that spur natural selection. We, alone in the known universe, are moral beings.
From sea turtles to the family dog, animals travel unerringly over long distances using geophysical cues. And it all evolved, independently, by chance! Believe that?