Genomics: Insight

Introduction:

Today in the United States Census, the Census Bureau uses the 1997 Office of Management and Budget standards on race to determine the five options that are given to citizens to select. Those options include white, Black or African American, American Indian or Alaska native, Asian, and Native Hawaiian or “Other Pacific Islander”. These classifications of race can be used to help people understand themselves, to feel connected to others around them, and (and/or, contrastingly,) to use as a means to treat others differently. But, how does biology inform these racial classifications? Populations that are classified as a particular race are not biologically discrete from other populations or have evolutionary independent lineages. Instead, all humans have much more in common, genetically, then they do different. Biology supports the idea that the current system of race is invalid due to the shared alleles among different races, and the immense differences between members of the same race, in particular African Americans.

Biology proves that the current system of race is invalid because of the shared alleles among different races.

Allele Similarities Across Regions

According to Britannica Encyclopedia, classifications in the U.S. came about as a form of social division built on the basis of what were thought to be natural differences between groups of people2. However, science has shown us that genetically, the groups of people divided into different races have a lot more similarities than differences. For example, Supplementary Figure 1A in reference 1 looks at 4,199 alleles in seven regions: America, Oceania, Central/South Asia, East Asia, Middle East, and Africa. The pie chart notes that when looking at all seven regions, they contain 46.70% of the same alleles. This means that while these populations are located in seven different regions around the world, nearly half of all their alleles are the same, disproving the idea that races are biologically discrete from each other. However, when the regions were studied individually, the percentages of shared alleles are much smaller. For instance, when looking at the East Asia region alone the percentage is 1.14% and in Africa the percentage is 4.05%¹. These small percentages show how genetically diverse a population can be, even if they live in the same region. Therefore, it does not make sense to place individuals into the same racial category solely based on location.

The pie chart notes that when looking at all seven regions, they contain 46.70% of the same alleles.

Haplotype Diversity in Populations

Placing a person into a racial grouping suggests that they are similar to other members of that race and different from other races. However, this is not accurate as those who are considered African American can be significantly different, genetically, from members within their own race. In Figure 2A of reference 3, the points plotted represent each population’s haplotype heterozygosity, which is the variation for one specific region of DNA across a population³. The x-axis represents how far away each population group is from Africa and the y-axis represents the average haplotype heterozygosity in the population. As seen in the figure, the populations in Africa are extremely genetically diverse, with around a 0.9 haplotype heterozygosity. This means that if two people from the same region (Africa) were to be selected at random, the odds that their DNA would vary significantly is high since the haplotype heterozygosity is very close to is 100% or 1. In addition, there is a very strong correlation (r = -0.76) between the distance away from Africa and the haplotype heterozygosity. The large r value indicates the high likelihood that as populations move further away from Africa, their haplotype heterozygosity decreases, meaning their populations are less genetically diverse. For example, the European populations are around 5,000 kilometers away from Africa and their haplotype heterozygosity is around 0.8. While 0.8 is still a relatively high frequency and correlates to a diverse population, two randomly selected people from the Europe populations would be more genetically similar than two people selected from Africa since Africa’s frequency is higher. Using that same logic, if a person from Africa and a person from Europe were to be compared genetically, they would likely be more similar to each other than two people from Africa would be, showing that racial categories can be misleading by implying similarities among people in the same race.

The populations in Africa are extremely genetically diverse, with around a .9 haplotype heterozygosity.

Conclusion

The concept of race in America has been a pivotal part of society since its creation. However, the studies described in this paper show that our current racial system does not provide an accurate depiction of human populations. Populations who would be considered part of different races tend to have many of their alleles in common, showing that races are not biologically distinct from one another. In addition, races, such as African Americans, can be so genetically different that members of different races can be more alike than members of the same race. While these classifications may be a convenient and organized way to divide up populations, when looking at them from a biological perspective, these categories are inaccurate. Nevertheless, race is dividing the United States now more than ever. The way our country places biases and values on individuals based on their race has led to challenges such as racial profiling, discrimination, and injustice that plague our nation today. However, if we all can understand how much different races have in common biologically, maybe that can help to unite us and realize that we are much more similar than we are different.

The races that make up our society have no scientific significance and therefore should not be used to define people.

References

1. "Genetic Structure of Human Populations.", Rosenberg NA et al, Science (2002), rosenberglab.stanford.edu/supplements/popstructSupp.pdf. Accessed 14 Oct. 2020.
2. Wade, Peter, and Audrey Smedley. "Race." Encyclopaedia Britannica, 28 July 2020, www.britannica.com/topic/race-human. Accessed 14 Oct. 2020.
3. "Toward a more Uniform Sampling of Human Genetic Diversity: A Survey of Worldwide Populations by High-density Genotyping." Xing, Jinchuan, et al, Genomics (2010), www.ncbi.nlm.nih.gov/pmc/articles/PMC2945611/. Accessed 14 Oct. 2020.