Subject: Why humans differ widely in size?

The average man is larger than the average woman, because in the past males 
competed among each others over females. The same thing in animals, gave little 
variations in size, comparing to humans. However, humans not only differ widely 
in size among ethnic groups, but also within the group itself. The dominant 
assumption among people of different cultural backgrounds (This is my 
observation, so far), that a man marries a woman which is shorter than he is, 
and therefore distribution of human height should have been around an optimal 
value, which gives the best chances of surviving the local environment and 
successfully competing with other males. Even observing isolated populations in 
documentary films seems to show a relatively wide range of sizes. I don't know, 
however, how that distribution was in ancient populations (Measuring skeletons 
or plaster casts of the victims in Pompei in Ancient Rome). Did body size 
become less important in everyday's life even early in human history? If so, 
why do we still take it into account, when chosing a mate and in many other 
activities as well?

Re: Why humans differ widely in size?