From an evolutionary point of view, maybe we already have a decent configuration for survival, next to the cockroaches obviously. While there is a certain degree of diversity amongst us, we are not as different from one another as, say, mole people. On the average we're between 5'-6', between 120-200 lbs (not scientific numbers, but you get the idea). Homo floresiensis (size of a hobbit) died out, and so did our cousin Neanderthal with somewhat different a physical and mental make up. This may not be because we're "better," but we've managed to get this far.

I'm sure a part of the reason is that we're intelligent, social creatures. We can work together, and complement each other. After all, in terms of purely physical traits, we're slower than a zebra, weaker than a lion, less agile than a monkey, etc. Yet somehow we beat them all. So perhaps that's the perspective we should use to look at questions about which body type is best for survival: our bodies, while decent, are no comparison to certain wild animals. So our best trait may be how we work together as a group, using our brains to overcome things that challenge our meager bodies.

Da Bing