Where do anthropologists think different races came from??

My last blog basically went over some of the things  I learn about the physical evidence anthropologists had to prove Darwin`s theory of evolution and natural selection. The physical changes that occurred as a result of early human migration and change of living environment can still be seen in various locations in the world. As we see today there are many different races in the world which can be recognized by their unique demographic physics. Some races like Europeans are usually blond, tall, have blue eyes and bony faces verses Africans who have darker skin color, dark eyes, dark hair, chubbier face and are usually shorter than Europeans. The picture below shows some of existing races in the world. 

some of human races

But where do these different races come from and why do these demographic differences exist if we all originated from Africa (where people have only dark skin)?? I used to ask this question a lot when I was little and surprisingly the answers  I got from different people didn’t really make any sense to me. In fact I got some really strange answers like “ we come in different colors and shapes because some races are better than others and God loves some races better than others” and things of that sort. It might seem really racist to a lot of people to hear someone say that but believe it or not I heard answers as such mainly from religious people around me.  So I guess thank God I took this biological anthropology class that talked about different theories about human origin and the reasons for having multiple races in the world.

“Out of Africa”  theory suggests that we all started off from the great land of Africa, where our ancestors lived for a long time and evolved into homo sapiens who later migrated to other parts of the world to replace other hominid species, including homo erectus. after Homo erectus migrated out of Africa the different populations became reproductively isolated, evolving independently, and in some cases like the Neanderthals, into separate species. This theory suggests that homo sapiens arose only in Africa which geographically could also include Middle east and that interbreeding had no role in producing new races and claims that modern human variation is a relatively recent phenomenon. The picture below is a map of “Out of Africa” theory. 

out of Africa model

Another theory called “Multiregional Continuity Model” suggests that although we did come from Africa when Homo erectus dispersed into other portions of the Old World, regional populations slowly evolved into modern humans.   According to this theory  some level of gene flow existed between geographically separated populations and that  all living humans derive from the species Homo erectus that left Africa nearly two million-years-ago. This theory unlike “out of Africa” theory suggests that the emergence of Homo sapiens was not restricted to any one area, but was a phenomenon that occurred throughout the entire geographic range where humans lived. The diagram below displays the "“Multiregional Continuity Model” and the other one compares it to the "Out of Africa model".

multiregional continuity model

multiregional continuity model vs. out of africa model