I'm not an anthropologist but I have read a few articles about this very issue. Apparently the Levant (middle east-ish) as a cross roads was luckily placed for the key domesticable species of animal and plant. In particular, the horse, the dog, cattle, pigs, wheat. Africa is vast and the few likely domestication candidates are widely spaces and in particular they lacked access to pack/labour animals that could be domesticated. The Zebra for instance is apparently notoriously difficult to train and has never been domesticated.
Western Europeans are an offshoot of those earliest civilisations who were lucky in the availability of key natural resources. The later resources of iron and coal and copper are meaningless without the farming revolution that Africa never achieved. The Sahara was obviously a huge barrier to the introduction of those benefits into sub Saharan Africa.
There is a very good book on the subject I mean to read sometime, if I can find the name I'll add to the post.