In the medical community, there is often this idea of “Nature vs Nurture.” It is the combination of our genes and our environment that create our physical existence. While this conversation is an incredibly important one, I think that the scientific community has done an incredibly poor job of accurately communicating the nuance of these concepts to the general public! Today we are going to break down “Nature” and next time we will take a more in-depth look at “Nurture”
During the 19th and 20th centuries, countless scientists studied molecular genetics in an effort to understand how traits, information, and diseases were down hereditary lines. During this time it was discovered that our genetic information was encoded by the sequences of biological molecules, Adenosine, Thymine, Cytosine, and Guanine, called nucleotides (A, T, C, G for short). Each “gene” in your DNA is a specific pattern of these molecules that codes for a protein that does a specific function to contribute to your body’s function (Alberts et al., 2020; Giani et al., 2020). In the early 21st century, this research culminated with completion of “The Human Genome Project,” the sequencing of the entirety of a human’s genome (“The Human Genome Project”, 2021).
That’s all well and good, but if we already cracked the code, then why can’t we genetically test for and fix any disease? The answer here is complicated. Just because they sequenced the order of As, Ts, Gs, & Cs, does not mean we understand the function of each gene, or what and how mutations and differences in the code cause each disease. When you consider the fact that there are around 6 billion nucleotides in the human genome and that each gene is somewhere between 10,000 and 100,000 nucleotides you can see how understanding the genetic consequences of every mutation is a complicated endeavor (Nature, 2001; National Institute of Health, 1988).
At this time, we would like to talk about companies that offer “genetic testing” in order to determine one’s “race.” What these companies offer pseudoscientific at heart. First off, they do not completely sequence your DNA. They look at “areas of interest” and compare these to others in their database. Not only does this lead to heavily biased sampling, but it allows them to make claims that have been dissolved by modern science. These businesses compare sections of your DNA and compare it to groups from their small databases, and make claims about the entirety of your genome and its relation to a whole population (Rutherford, 2018; Jorde & Wooding, 2004). Specifically, the claim that you can tell someone’s race by their genetics! Human beings share 99.9% of the same DNA with all other human beings. There is NO known genetic difference that separates races (Harvard Graduate Dept. of Arts & Sciences, 2017). By insinuating that race is heavily genetic, they add fodder to the racist argument that one race is genetically superior to another.