Yes and both continents have been open to migration since the dawn of man.
We are all over the place on this subject, one minute it's Asians and the next Africans.
And I agree with you there, but maybe that's a consequence of their surroundings.
For example, there's very few Asians and even less Africans in the village I grew up in but crime is at an all time high.
The place is in ruins compared to the era I grew up in as a child 80's-90's.
You have little scrotes running around, stabbing and shooting each other up.
That can't be blamed on the Paki's or Niger