@Starver (&Max): Funny thing is, evolution is a lot slower than the slowest human. Stupid people beget smart ones, and vice-versa. The largest increases in IQ that we've had in the world were through education, not breeding. [...]
IQ is a stupid measurement anyway (no pun intended!). Even if I'd not come across so-called IQ tests that quite obviously have biases towards education/knowledge in many of the questions[1] I don't believe the values that I tended to get[2] from the ones that are better constructed and even differentiate individual IQ measurements down to spacial, numeric, logical, and other sub-categories.
I was more thinking of something equivalent to "Island populations", the separation of individual genetic intermixes from each other for
sufficient time (really many millennia, not sure actually how long it would take in hominids, and there are still some controversies of whether Neanderthals and our ancesters
could have interbred, regardless of whether they
would have done so[3][4]...
[1] e.g. Unscramble some anagrams (needs at least some knowledge of English), and then say which of these is the odd one out (normally I'd say that was a knowledge issue as well, although, frankly, which would
you say was the odd one out of Kennel, Cave, House and Tent? That's not an IQ question, that latter part is like something from a "no answer is wrong" psychometric test where your choice indicates how you think...).
[2] Too high, if it matters. Although even IQ aficionados who believe in the things tend to say that once you get near the 200s it becomes meaningless/inaccurate.
[3] "Oooh, I really like a bit of prominent eyebrow in my men, that's why I'm always dating those Neander Valley guys... I know daddy said I should find a nice guy fresh out of Africa, but I'm a modern cavewoman and I'm entitled to date who I want... And if Grrrr prefers his females without hairy backs, I want to be in there before anyone else from my tribe gets the taste for his kind of 'a bit of rough'...
[4] And, last I heard, they were still saying there was no sign of Neanderthal ancestry in any modern human. But that's open to discussion and might be toppled by the next bit of genetic analysis done, if it hasn't been already...