Question:

I have a science background and looked at theology too.  I was wondering if you had an answer to the variations between different races if we descend from Adam and Eve.  For example, if we say that we came from them, how do we make sense of different skin colour and eye shape?  Even if we said Adam and Eve were created thousands of years ago, and their children spread out (gen11) and got different sunlight and so different melanin changes, how did these changes get into their DNA that would cause them to pass onto their children (since black people have black kids, white have white kids)?

Answer:

The genetic differences between races is really quite small.   The genetic similarity between Caucasian, Asian, Polynesian, Native American and black African is nearly 100%.   There is much more similarity between the races than there is difference.   In fact, the genetic variation within a single “race” is vastly larger than the difference between that “race” and another.   The importance of race is often exaggerated, from a scientific perspective.  Of course, from a social or anthropological perspective the difference may be larger.

Bottom line, the number of mutations or simple genetic modification by natural selection required to change one human race to another is really quite small.  Those living is areas of the world where there is  very little sunlight will see their skin start to become lighter in order to allow more healthful UV radiation through within just a few hundred years.   The reverse will happen to those exposed to very strong natural radiation nearer to the equator.   A single mutation could create the different eye shape common in the East, for example.  In fact, scientists believe this is what happened.  If this happened at the time humans were spreading into Asia, it would have become the “normal” phenotype in Asians.   Africans have a natural partial immunity to malaria which was produced by the same mutation which can cause sickle cell anemia.   Again, this change can occur and spread across a population in several hundred years.   Natural selection always does its work.   Scientists have estimated that the amount of time over which the “races” have diverged genetically is on the order of several thousand years.   I do not know when Adam and Eve lived, but if they lived 20,000 years ago, then all the genetic diversity in humans can be explained by natural, well-understood processes.

John Oakes