Well, as far as I know, they haven't found any specific genes which are relevant to our intelligence. It is true, that global IQ comparisons show blacks as the least intelligent and asians as the most intelligent. But honestly, I think that has more to do with culture and social infrastructure than it has to do with race. Whilst the western world's educational system is well structured, and virtually no one is left without at least 8-10 years of basic education, the African system is broken and very few are given any education at all. I'm sure, if you made a similar study comparing races within the borders of a western country, taking only people who have lived there their whole lives, the margin wouldn't be as high, if even existent at all.