04-30-2016, 06:36 AM
Here's my nutshell explanation that I just posted on Greg Stevens' blog entry... Evolution Q&A: Why did only humans become intelligent?
You really did the theory of evolution justice! I, on the other hand, really suck at doing theories justice. Watch...
So... humans are exceptionally intelligent. What is exceptional intelligence good for? It's good for solving exceptionally hard problems. But why did early humans, out of all the animals, need to solve exceptionally hard problems? It's because out of all the animals, early humans had the greatest ability to (simultaneously) allocate the widest variety of resources. This exceptional ability was the result of having hands, arms and... walking upright.
With quadrupeds... all four limbs are primarily dedicated to allocating a single resource... the animal itself. But this specialization is a continuum that ranges from horses to raccoons to chimps. Horses obviously have four legs. All their limbs are quite specialized to allocating only the horse itself. None of the horse's limbs are remotely capable of allocating other resources. What about raccoons? Do they have four legs? Well, their front limbs are reasonably capable of allocating other resources. Chimps definitely do not have four legs. They have two legs and feet and two arms and hands. They are quite capable of allocating other resources with their arms and hands.