This map was created by the Institute for Global Communications while conducting their Demographic, Environmental, and Sercurity Issues Project. Apparently the map is based off the article by John H. Tanton, ”End of the Migration Epoch,” reprinted by The Social Contract, Vol IV, No 3 and Vol. V, No. 1, 1995.
I can’t validate the exact accuracy of the map, but it’s the most useful version I have been able to find. If someone has a better animated map of historical human population growth please send my way. On this particular map, each black dot represents one million humans.