The ‘Perfect Human’ Is a Puerto Rican Woman

A blog post entitled “The Perfect Human is Puerto Rican” in the normally staid blog, “Bits of DNA,” which provides “Reviews and Commentary on Computational Biology,” has made headlines in many other news sources.  They include The Latin Times and The Huffington Post, among others. The article was tweeted much more than most articles on computational biology, to say the least.

The post was really about James Watson’s racist attitudes

The blog post was really not about Puerto Ricans. It was about James Watson, a Nobel prize winning scientist with an interest in eugenics, the idea that humans can (and should) be genetically perfected by selective breeding.

Watson’s view, according to “Bits of DNA” publisher Lior Pachter, is that this perfection would lead to people like Watson himself, a Scotch-Irish Chicagoan. Pachter suggested that an analysis might result in a different answer.

Finding the perfect human through DNA

First, Pachter defined perfection in a human as having the “good” forms of alleles (versions of a particular gene) in the case of every gene. For example, there is a gene associated with addiction to alcohol. Having the “good” version  would mean not having a genetic inclination toward alcoholism.

There are a number of genes with “good” versions associated with not having a certain disease or problem and “bad” versions associated with having that problem. Some of those genes have been mapped in a public database. Pachter created a mathematical construct of a person who had all good alleles — no genetic tendency toward Tay-Sachs disease, obesity, cystic fibrosis, Huntington’s disease, etc.

He then used computational analysis to place the hypothetical ‘perfect human’ into population groups. The ‘perfect human’ was put in with mathematical models of actual humans and the people were sorted according to their place of origin. The result was that the imaginary ‘perfect human’ was, when looking at location of origin, closest to a Puerto Rican woman.

Pachter followed with other computations which indicated that the perfect human was completely different from real humans in significant ways that would cause a biologist to conclude the person was not human. That point in his article didn’t get reported as much.

Why Puerto Rico? Rich history

Why would the absence of “bad” alleles lead to Puerto Rico? There is a tendency for “bad” alleles to show up in specific populations where they might have been useful at some time in human prehistory. For example, a gene associated with cystic fibrosis seems to be associated with resistance to cholera. That gene is more often found in European populations which often were afflicted with the disease.

Because of this tendency among “bad” genes, Pachter says, one would expect the person with only “good” alleles not to be strongly associated with a particular place, from a genetic point of view. In other words, one would expect a more complex heritage. People from Japan or Iceland, for example, tend to have ancestors from Japan or Iceland. People from Puerto Rico, however, have a very varied heritage.

Are there “perfect” humans?

Taras Oleksyk from the Department of Biology at the University of Puerto Rico Mayaguez responded with an article explaining “why there can’t be a perfect human, from Puerto Rico or anywhere else.” The article points out that the data used is incomplete, that the concept of a “good” or “bad” allele is inaccurate, and that, as noted above, the perfect human would actually not be human.

Oleksyk also wrote, “Not that anyone has really read the article. Taken by the flashy title… the news spread across the social media as a human wave in a stadium.”

Stopping with headlines misleads us

That is certainly true. Check out a sampling of the headlines the post generated:

• Biologist Says Puerto Rican Women Possess Ideal Genotype
• Berkeley Biologist: Puerto Ricans Are Closest To Perfect Physical Specimens
• New Study Reveals The Perfect Human Genetically Speaking
• Puerto Ricans are perfect, says a Berkeley biologist
• Science Proves Jennifer Lopez to Be a Near Perfect Human

Presumably some of these articles — and a Google search came up with more than a million results — were written by people who read and understood the original blog post, but decided to go with the gripping headline.

Another response to the article, by Angel Carrion, translated an important point made by Rafael A. Irizarry of the Harvard School of Public Health:

In spite of our current social and economic problems, Puerto Rico has a lot to be proud about. In particular, we produce great engineers, athletes, and musicians. To credit their success to the “good genes” of our “race” is not only scientifically absurd, but also disrespectful to these individuals who through hard work, discipline, and dedication have achieved what they have achieved. If you want to know if Puerto Rico had anything to do with the success of these individuals, ask a historian, an anthropologist or a sociologist, but not a geneticist.

The original blog post intended to debunk the idea of a genetically perfect human. Responses instead took up the very “master race” concept the post scorned. Irizarry left out many accomplished people of Puerto Rican heritage when specifying only “engineers, athletes, and musicians,” as examples of excellence among Puerto Ricans, but made the essential point that the concept of genetic perfection is at its foundation racist.