I see after I awaken in my time zone that there have been quite a few thoughtful comments on the interesting article kindly submitted here, many of them replies to top-level comments. For participants on Hacker News who like to read whole books or scientific articles on facts about the world they live in, I recommend a specialized bibliography on race

https://en.wikipedia.org/wiki/User:WeijiBaikeBianji/Anthropo...

kept in Wikipedia user space and updated from time to time. The actual articles on Wikipedia about the topic of "race" are mostly very low in quality and frequently edit-warred, with one of those articles being one of the ten most edit-warred articles on all of English Wikipedia.

The basic fact we can all rely on as we think about these issues is that we are all very closely related to one another, throughout humankind. Every human being is more closely related to and more similar to every other human being than most people imagine. That's a consistent finding of molecular genetics research.

The United States Census Bureau says

"The U.S. Census Bureau collects race data in accordance with guidelines provided by the U.S. Office of Management and Budget (OMB), and these data are based on self-identification. The racial categories included in the census questionnaire generally reflect a social definition of race recognized in this country and not an attempt to define race biologically, anthropologically, or genetically. In addition, it is recognized that the categories of the race item include racial and national origin or sociocultural groups. People may choose to report more than one race to indicate their racial mixture, such as 'American Indian' and 'White.' People who identify their origin as Hispanic, Latino, or Spanish may be of any race."

http://quickfacts.census.gov/qfd/meta/long_RHI525211.htm

In other words, "race" categories used by the United States government are arbitrary and are not based on science. A confirmation of this fact is the disagreement between any two countries' categories for "race"--the same individual can change categories as the individual crosses national borders.

Feldman, Marcus W.; Lewontin, Richard C. (2008). "Chapter 5: Race, Ancestry, and Medicine". In Koenig, Barbara A.; Lee, Sandra Soo-jin; Richardson, Sarah S. Revisiting Race in a Genomic Age. New Brunswick (NJ): Rutgers University Press. ISBN 978-0-8135-4324-6. is a good current book chapter on medical implications of race research informed by genetics. The article notes on page 93 "Finally, it must be borne in mind that the taxonomic problem cannot be inverted. That is, while clustering methods are capable of assigning an individual to a geographic population with a high degree of certainty, given that individual's genotype, it is not possible to predict accurately the genotype of an individual given his or her geographical origin. Thus, knowing an individual's ancestry only slightly improves the ability to predict his or her genotype. The more polymorphic the markers, the more difficult this is." Another book chapter, Harpending, Henry (2007). "Chapter 16: Anthropological Genetics: Present and Future". In Crawford, Michael. Anthropological Genetics: Theory, Methods and Applications. Cambridge: Cambridge University Press. p. 457. ISBN 978-0-521-54697-3, points out that "On the other hand, information about the race of patients will be useless as soon as we discover and can type cheaply the underlying genes that are responsible for the associations. Can races be enumerated in any unambiguous way? Of course not, and this is well known not only to scientists but also to anyone on the street." A specific example of "race" failing to explain a medical observation is hypertension (high blood pressure), already mentioned in this thread before I posted. The book chapter by a specialist on the development of blood pressure medicines, Kahn, Jonathan (13 August 2013). "Chapter 7: Bidil and Racialized Medicine". In Krimsky, Sheldon; Sloan, Kathleen. Race and the Genetic Revolution: Science, Myth, and Culture. Columbia University Press. p. 132. ISBN 978-0-231-52769-9. points out that "In medical practice what matters is our shifting understanding of the correlations between such evolving social identities and the evolving economic, political, and environmental conditions to which they may be related. For example, what are we to make of the fact that African Americans suffer from disproportionately high rates of hypertension, but Africans in Nigeria have among the world's lowest rates of hypertension, far lower than the overwhelmingly white population of Germany? Genetics certainly plays a role in hypertension. But any role it plays in explaining such differences must surely be vanishingly small."

I have been to different parts of the world, and have met people from all over the world. Sometimes I have met persons of one "race" who look just about exactly like people I know from another "race," and I have found kindred people (as to any personal characteristic you care to name) among people from all over the world of all different "races." The race categories are not informative, or at least not informative about individual genomes. In some societies, "race" is a salient enough category that an individual's personal experience can be profoundly influenced by race categorization. If you haven't read the book before, you could read the book Black Like Me by John Howard Griffin to learn more about that.