November 5, 2021
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The Truth About DNA Tests And Determining Race

Are you interested in learning about your ancestry? Consider the reports offered through Genomelink.
Tomohiro Takano

There is a lot of misinformation about what DNA tests actually report. Many of the over 26 million people around the world who have sent in a DNA kit for testing assume they will know their ancestors based on race. Since 2013 and the beginnings of the home DNA testing industry, the companies have been careful to let people know they will get information on their ethnicity, which is not the same as race. 

What the Tests Report

This is an important distinction in understanding just want the test reports. The report provides information on the percentage change of having an ancestor or ancestors from a specific part of the world. 

The numbers presented with the report, which are in percentages, are an estimate of that percentage in your genome. For example, if the DNA test indicates there is a 50 percent chance you have ancestry from Africa, that is not the same as being 50% African. 

The Science Behind the Tests 

The confusion comes in the small amount of DNA that is actually different between people. Approximately 99% of all human DNA is the same. This is what makes us uniquely human. Human DNA is the blueprint or the genetic code for the human species. 

Human DNA contains about 3 billion bases, which are combined in unique sequences to create specific elements of each person. DNA tests identify the less than 1% of the bases that are not the same as others. These are sometimes known as single-letter differences. 

This information is then compared to large samples of other DNA. This comparison can include millions of DNA samples. It looks for similar variances that are linked to different populations and areas. 

The Challenges 

At best, the science of DNA testing at its current level can provide information that allows researchers to say, with a statistical probability, that the differences in your DNA are like the DNA from a larger group of people that are found in a general geographic area. 

To make matters more complicated, even you know where your family lived back a given number of generations, it is still impossible to pinpoint the exact genetic lineage as DNA is not shared during conception in a 50/50 split. It is much more complex than that, with DNA changing over time. 

It is even possible with a home DNA testing kit to have different ancestry results from children in the same family when going back generations. Siblings in the same family, unless they are identical twins, have slightly different DNA, which is why they look different and may even have different health issues. 

Skin color is another variable that cannot be explained by DNA and ancestry. While results can tell if you have a high estimate of Asian or African ancestry, it cannot predict if you have a particular skin color or eye shape. However, for information on the probability of where you are from, these tests provide a picture of your ancestry and family history. 

If you are interested in learning more about your ancestry, and even about where your ancestors may have traveled, consider the reports offered through Genomelink

DNA Tests Can Show Ethnicity, but Not Race

DNA testing cannot determine what a person’s race is.

Many of the 26 million+ people who have obtained their DNA results are surprised to discover small contributions to their genetic makeup from far-flung geographic regions.  But just because  a white person discovers that they have a 3% probability of African ancestry, this does not make them Black. Though Americans are regularly grouped by race – even on the U.S. Census – DNA testing is helping people understand what geneticists have always known:  the notion of “race” is a socio-political construct, not a biological one.  Consider the designation “Latinx”, which typically includes ancestry from indigenous Americans, Iberian peoples, other Europeans, and North Africans.  This illustrates how “race” is a contrived notion.

Using DNA to Determine Ethnicity vs. Race

DNA testing provides information that allows geneticists to assign a probability that our ancestors came from a specific region of the world.  This is our geographic ethnicity.  

While a group of one’s ancestors may share a similar phenotype (appearance), this is no guarantee that a given individual today will share these characteristics.  Skin color is determined by a complex interplay of dozens of genes that affect melanin in the skin.  This can create a spectrum of skin tones in the same family.  Even if you know where your family lived a given number of generations in the past, it is still impossible to pinpoint one’s exact genetic lineage.  Genetics vary with each generation, as only 50% of a parent’s genes are passed to children. This is why siblings have different DNA and can look very different.   This effect is multiplied over many generations.  

DNA Testing’s Effect on Race

Approximately 99% of all human DNA is the same.  DNA tests examine the <1% of our genes that is not the same as everyone else. In time, DNA tests may render the social construct of “race” increasingly less useful as we better understand our ancestral heritage, and discover that we share roots with people from all over the world.

Tomohiro Takano
Tomohiro Takano
Co-Founder and CEO