Jews are no more related to Africans than any other race or ethnicity is. There are some African Jews (such as the Ethiopian, Ugandan, and South African Jewish communities), but Ashkenazi and Mizrahi Jews are generally not considered to be related to Africans (such as the Bantu, Nilo-Saharans, or the Khoisan peoples).
I saw The Nutcracker performed in Pretoria once during the Christmas season. Some of the dancers were black. I have to assume they were Africans. Opinion from a ballet dancer in Africa yes quite a lot and they are very good you even get extremely good performers that dance swan lake and some have even gone to a father extent and started doing ballets on ice which is really fascinating.
Dark skin is an adaptation to hotter climates. Africa is generally hot, so humans adapted and became black. Furthermore, Africans are not the only "black" people in the world. Several unrelated groups such as the Aborigines of Australia and Negritos of Asia are dark-skinned, but are not directly related to Africans.