[quote]Several hypothesis have been proposed.[/quote]Can you please send a URL address of your source? Thank you.[quote]As for intelligence, it's just another example of natural selection at work.[/quote]How? Natural Selection favors the physical adept. Did Darwin's finches assume that it would be better to "think" their beaks into a specific shape?[quote]The smarter organisms were better at staying alive, and they were also better at acquiring resources, making them more attractive to mates.[/quote]Smartness does not guarantee survival. Hypothetically, if I were to put a hungry lion and an unarmed human in a Roman Colosseum during the mid-first century, how long would it take for the smartest one to win?[quote]This made for more offspring with intelligence genes.[/quote]Intelligence is not a gene. If I married a lady with a Doctorate's and I myself had a Doctorate's, will our children have at least a Master's?