Biology and Race

In a time in which the UK and USA are spear-headed by right wing leaders whose derogatory comments on people of differing races would fill a small textbook, I felt it pertinent to explore the similarities and differences in cultural and biological race discrimination. Ever since the ideas of inheritance and evolution were in circulation, people were using them to explain observable differences between individuals. The Co-Father of Evolution himself, Charles Darwin, has an infamous cousin, Francis Galton, who came up with his theory of Eugenics; only allowing the breeding of people in society with desirable traits. This lead to John Harvey Kellog founding the Race Betterment Foundation in 1911 (he also invented cornflakes as an anti-sex mechanism) and fuelled the rise of Facism, most notably in 1930s Germany. In addition, questionable studies reporting inherent differences in intelligence between black and white people in America in the 90s further aggravated the prejudice against the black communities. Modern techniques to sequence and map DNA of people from all around the world has helped us break down barriers and opened up ideas of how populations of humans have evolved. So what is DNA?

DNA is the code which is often described as our ‘blueprint’. It helps determine what physical traits and characteristics we have along with a multitude of other things happening at a microscopic level. The blueprint is written using four letters: A, T, C, G, the same four letters used for humans, dogs, oak trees, mushrooms, and bacteria. You have a total of 6 billion of these letters in your DNA ‘code’. Just like the sequence of letters determine the words spelt out in a book, the specific sequence of these four letters can determine whether you have brown or blonde hair, green or brown eyes, or what blood type you are. The term genetic variation is used to describe differences in the DNA between individuals (I may have a G where you have a T etc. etc.). Modern Biology likes to explore the differences in the DNA of humans and see if these can be used to explain differences in our traits or history. So what is the history of humans?

Modern humans, Homo sapiens, evolved in Africa around 200-300,000 years ago. Around 80,000 years ago a subset left Africa into Asia. Further migrations of groups led to them reaching Australia by 65,000 and Europe by 45,000 years ago. Along the way they both mated with and wiped out the Neanderthals who were living there at that time, which explains why up to 4% of DNA in a European or Asian is from ancient Neanderthals. Finally, modern humans crossed the Bering Strait and reached the Americas around 15,000 years ago. Since only a small sample of the human population left Africa and colonised the rest of the world what we see is that the genetic variation in Africa is much higher than anywhere else. This is like if you had a bag of 100 smarties, took 10 random ones out which just so happened to have 3 yellow, 4 red and 3 green (no white, blue etc,) and put them in a new bag. There would be much less variation in your new bag than the old. What we can observe from this is that two individuals from Africa can have DNA more different than if we compared a European to an African; discrediting a biological notion of differences between continents. So what differences can we observe on a DNA-level?

Early studies show that of all the variation in DNA between people, less than 10% is specifically down to the fact of people living on different continents (see picture). The majority of the differences can be observed between two people living in the same population. More recent studies have highlighted this, stating that the most common differences in DNA are shared across all the continents, with only rare DNA differences being specific to certain groups. Examples of these differences include DNA coding for light skin pigmentation in Europeans as an adaptation to absorb more vitamin D and also DNA coding for the ability to digest milk as an adult (lactose tolerant). This is not the norm worldwide but has evolved due to people relying on cow milk for its nutritional value. So what does this all mean?

As is evident from the data there is very little differences in DNA between people which can be explained by them being from different areas, background, races etc. The majority of differences we do observe are just between individuals and most of the rest are due to adapting to local conditions such as lower sunlight levels, different diets, and protection against certain diseases. Race is a social not a biological construct; it is the culture and environment which helps create prejudice and xenophobia. As a positive, social constructs are far easier to change and escape from than biological ones and therefore we can hope institutions develop to create more inclusive attitudes to combat the rise of far-right politics in certain areas today.