That's not entirely correct... Sure, most Arabs may have some degree of 'Negroid' ancestry but that is usually very scant. Arabs have intermarried a lot more with 'light skinned' populations than they did with Negroid populations, this is well-documented. Where did you get that information from that very few Arabians have Turkish or Iranian blood? looool, they all have substantial levels of Persian and Turkish blood. I cannot find a study dedicated to the autosomal DNA of Saudis... Modern Arabs have only ~55% 'Arabian DNA' or less than that. If you have a look at their haplotypes though, almost all of them are of Eurasian origins.Only around 42% are thought to be of Arabian origins (JM267). @Canuck is right that the ancient Arabians were generally darker, this is even in their literature dude. The bedouins have a lot less African admixture in their genome whilst the urban dwellers are a lot more mixed with Africans and other ethnicities in general. The Najdi bedouins Arabs make fun of the Hijazis for being 'less pure' Arabian blooded than themselves. There may be some Arabs who are darker than their ancestors, but that's not the commonplace. According to estimates, 75% of the genome of medieval Arabs (well before the mass enslavement of Africans) were 'Bedouin-like'.This estimation was made by making a comparison between populations: http://www.eupedia.com/genetics/spain_portugal_dna.shtml
Have a look at these pictures.
Isolated Arabian bedouins:
Khaleeji urban dwellers
