by Gary Marchant
So the most recent estimate published this week is that humans only have about 19,000 protein-coding genes, down from previous estimates in the 22,000-25,000 range, and way down from the pre-Human Genome Project conventional wisdom that humans had 100,000-250,000 different genes. The new study is available online (for free).
But it has not only been an interesting week with regard to the number of human genes, but also with respect to what those genes do. There have been a burst of articles this week on genetic influences on human behavior and characteristics. For example, in an online New York Times op-ed on Tuesday, July 8, columnist Thomas B. Edsell reviews some recent studies suggesting that genetics play a major role in character traits such as “authoritarianism, religiousness and conservatism,” all of which likely influence political preferences and orientation. Meanwhile, an article in this week’s Economist summarizes the results of a recently published study on musical ability and genetics with this admonition: “Practicing music without the right genes to back that practice up is indeed useless.” And finally a new study just out finds that about half the genes influencing a child’s reading ability also play a role in their mathematics ability. (thanks to Kirk Hartley for this tip).
While the relationship between human behavior and genetics has been the subject of much hype and distortion in the past, there is no question that genetics (like the environment) play a major role in our behavior and abilities, and we are likely to get more and more findings going forward like those listed above reporting on associations between particular genetic variants and specific behaviors or abilities. As we enter the era of whole genome sequencing, most of the attention so far has been on the medical and health information that will be disclosed by sequencing, but the expanding repertoire of genetic variants affecting behavior will also be available once a person’s whole genome has been sequenced. Unlike the health data, there will likely be much less legal protections as most oversight only applies to health data (e.g., HIPAA privacy rules, FDA oversight). The only prediction that can be made with certainty is that it is going to be an “interesting” and rocky road ahead.