Response to "Does Race Exist?"

Here is the link to the original article.

  We usually define the race of a person by his geological origin and the culture of his country. However, from this article, I understand this definition is only valid through a biological standpoint, but it is inaccurate to determine the race of a person through his skin color and facial features. Usually, the genetic information we own can be used to distinguish human groups having common heritage and to assign individual to particular ones, and this information can help us find our races.

  There are tiny variations within our genes, and they are called polymorphisms. Polymorphisms contribute to differentiation between individuals. One of the useful classes of polymorphism is called Alu sequence, which is made of short pieces of DNA that are similar in sequence to one another. From research, we found out that the Alu sequence is heritable, which means that it can be passed on to the next generation. If 2 people have Alu sequence at the same spot in genome, they must be descended from a common ancestor. Therefore, the Alu sequence is a genetic marker, which means a inherited mutation in the DNA. According to the documentary “Journey of Man”, a genetic marker in our DNA can help us trace our ancestry, which can also lead to our geological origin.

  However, the skin color and facial features cannot determine the race of a man, since they can be strongly affected by the environment. The aboriginal Australian and sub-Saharan African people may have the same skin colors since both of them are exposed to strong sun, while natural selection can make the people in same group look more dissimilar.  
  And finally, it is important to find out the relationship between races and genetic variations because several polymorphisms different in frequency from group to group may have different effects on health. For example, some of the most common diseases like hypertension or diabetes are the results of polymorphisms in several genes, and each of them has a small influence of its own. Therefore, scientists may have to rely on one's ancestry to find out information for the treatment. 
  In conclusion, the article talked about how the biological explanation of races and ethnicity are related to genes, physical features and health. It is true that one can find out his ancestry through tracing multiple inherited mutations in his genes. Even though ethnic groups may share differences in physical features, but through the study of our DNA, finding out that every ethnic group are interconnected with another certainly brings us one step closer to discovering the dawn of man in the course of history.