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

Discovering Biological Anthropology

As a student of mechanical engineering I have been taking all science classes related to my major and didn’t really have to take any biology related classes which makes me feel incredibly lucky since I have a pretty bad memory. Last summer I was informed by my academic adviser that I wasn’t all that lucky and that in order to graduate from sixth college I had to take at least one course in biological sciences area. I had taken one biology class before and despite my enormous amount of effort to get a passing grade I had failed the class and so taking a biology class was not an option for me. I decided to take a psychology class because my friend who had taken it before told me that it was a pretty easy class and so I went ahead and took that class expecting an A + or in worst case scenario a B+.  Two weeks into the class I changed my grading option to pass/no pass realizing that psychology was not something that I could get a good looking grade in. About halfway through class I just really wasn’t so sure if I would be able to pass the class and at the end I ended up not getting a passing grade. Having failed both  biology and psychology classes, I had no other option but taking my chances with anthropology class which I expected to be as horrible as those two other classes. The first thing I did after enrolling in anthropology course was changing my grading option to pass/no pas fearing and expecting to have a hard time memorizing all those long and difficult scientific names.

Evolution of human

The first day of class I was very much surprised that I actually loved what biological anthropology was all about. I was so interested in the topics covered that memorizing those scientific names was not a pain any more.  What was amazing about this class was that although I had previously heard about Darwin and his evolution theory, I had never actually read about the scientific evidence that back this theory up.  The word “Evolution” as many of you already know refers to changes that occur over time in proportion of individual organisms differing in one or more inherited traits. Evolution explains how a specific specie can physically change over time and what causes these changes to occur. In 1858 the theory of natural selection  as a driving mechanism of such changes was first proposed  by Charles Darwin and Alfred Wallace. Natural selection is a process in which some traits become either more common or uncommon due to environmental effects and is key to species survival especially when dramatic changes occur in habitats of those species.  

 As you can see in the pictures below, people living in central part of Africa are tall and thin verses Eskimos who are much shorter and have more body fat to protect them from cold. The differences that exist between these two populations demonstrates how natural selection helps species to adapt to their environment and survive in harsh conditions that others will definitely not be able to survive in.

Native Africans

Eskimos

I'm absolutely glad that I ended up taking this class since it stimulated a lot of thinking and doubting which I benefited from. I feel like I grew as a person by exposing myself to something that was way off my mind at the time and learned so much about human evolution and as a person who was a nonbeliever of evolution I suggest other nonbelievers to look into the evidence, ask questions and search for the answers to find out more about evolution.