600 words

NOTE: This article was once part of one excessively long unpublished article that has since been divided into multiple small articles. Check the “Debunking Race Denialism” post tag for the other articles in this series.

Contents

  1. Intro
  2. Origins of “99.9%”
  3. A genetically significant difference?
  4. TL;DR Summary:
  5. Appendix: 23andme

1. Intro

This is the quintessential race-denialist argument. It fits very neatly into the modern globalized worldview and is nearly impossible for the average individual to debunk, since 99.9% of people know absolutely nothing about genetics (and why should they?).


2. Origins of “99.9%”

The “99.9%” figure comes from a study conducted in the year 2000 by the J. Craig Venter Institute. The same team of scientists conducted another study in 2007, revising the figure to 99.5%, which is the number you’ll find cited on many mainstream genetics websites, like 23andme. Shockingly, race denialists still haven’t updated their claim that “humans are 99.9% identical” — probably because “humans are 99.5% identical” doesn’t make for snappy propaganda.


3. A genetically significant difference?

This 99.5% similarity (or 0.5% difference) does not refer to genes, but ‘base pairs,’ which form the “rungs” on the “ladders” of our DNA. Genes dictate our phenotypic characteristics, and they’re often encoded by large quantities of base pairs.

What we need to know is whether or not a 0.5% difference in base pairs is substantial enough to measurably impact our genes. The answer is: yes, absolutely.

Consider that humans share 98.8% of our base pairs with chimpanzees, ~98% with gorillas, ~97% with orangutans, and ~90% with cats. The 0.5% difference between human races is only 0.7% less than the difference between humans and chimps (98.8% the same), and 1.5% less than the difference between humans and gorillas (98% the same).

Small changes in DNA lead to big changes in phenotype.

One single base pair difference can dramatically alter the functions of a gene. Additionally, one single gene can be responsible for controlling multiple other genes, so a small base pair difference can theoretically have a large knock-on effect. Humans have around three billion base pairs, so a 0.5% difference equates to fifteen million base pairs. Even if human base pairs were 99.9% the same, that would equate to a difference of three million base pairs.

Finally, the majority of human DNA is non-coding, meaning that it doesn’t define our gene expressions. Non-coding DNA accounts for a colossal 98.5% of our genome (total DNA). Comparative genomics estimates that 8 to 15% of our non-coding DNA is in some way biologically functional, but we have almost no idea what any of it does. (See: http://archive.vn/7bQXA, http://archive.vn/KGvAj, http://archive.vn/YxPNG).

So, according to current data, humans are not “99.9% the same” — we share 99.5% of our base pairs, but only 1.5% of an individual’s base pairs actually code their genes. Confused yet? The fundamental point is that small changes in DNA lead to big changes in phenotype. If we argue that race doesn’t exist due to a 0.5% difference in DNA, we may as well argue that chimps and gorillas don’t exist either.


4. TL;DR Summary:

  • We’re 99.5% the same, not 99.9%
  • The 0.5% difference between races is only 0.7% less than the difference between humans and chimps (98.8% the same), and 1.5% less than the difference between humans and gorillas (98% the same).
  • This 0.5% equates to fifteen million base pairs
  • 98.5% of our DNA is non-coding, meaning that only 1.5% of our DNA defines our gene expressions
  • In terms of DNA, a difference of 0.5% is significant

5. Appendix: 23andme

The framing of 23andme is particularly funny. Since their DNA tests constantly prove people to be 100% “racially pure,” they have to throw in a lot of nonsense about how interconnected humanity is and how, despite our vast differences, we are all “the same.”

What do you think Google is doing with all of the DNA information that 23andme gives them for free?