It is all around us. It is an illusion and yet profoundly real. What we perceive as race is one of the first things we notice about each other. Skin: darker or lighter. Eyes: round or almond, blue, black, brown. Hair: curly, straight, blond, or dark. And attached to these characteristics is a mosaic of values, assumptions, and historical meanings. We can see differences among populations, but can populations be bundled into what we call races? How many races would there be? Five? Fifty five? Who decides? And how different would they really be from one another? >> The measured amount of genetic variation in the human population is extremely small. That's something that people need to wrap themselves around, that genetically we really aren't very different. >> In fact, genetically, we are among the most similar of all species. Only one out of every thousand nucleotides that make up our genetic code is different, one individual from another. These look-alike penguins have twice the amount of genetic difference, one from the other, than humans. And these fruit flies, ten times more difference. Any two fruit flies may be as different genetically from each other as a human is from a chimpanzee. >> My favorite trivia question in baseball is which Italian-American player for the Brooklyn Dodgers once hit 40 home runs in a season. No one ever gets it right, because the answer is Roy Campanella, who is as Italian as he was Black. He had an Italian father and a Black mother. He is always classified as Black. You see, American racial classification is totally cultural. Who's Tiger Woods? Who's Colin Powell? Colin Powell is as Irish as he is African. Being Black has been defined as just looking dark enough that anyone can see you are. >> Now the SPHAs fight a path through the Celtic defense. >> In the urban environment of the 1930s, Jewish teams dominated American basketball. >> Bud Castleman shoots from outside. It's good! >> Sons of immigrants—theirs were the hoop dreams of the day. >> And it was said that the reason that they were so good at basketball was because the artful dodger characteristic of the Jewish culture made them good at this sport. There are strong cultural aspects of what sports individuals choose to play. It has to do with the interaction of individual genetic background, of opportunity, and training. History shows us that as opportunities change in society, different groups get drawn into sporting arenas. >> By 1992, America's Olympic Dream Team was almost completely African-American. Ten years later, 20% of NBA starters would be foreign born; the top NBA draft pick, Chinese. In the 1960s, Richard Lewington decided to find out just how much genetic variation fell within and how much between the groups we regard as races. A new technology enabled him to do pioneering work. >> And that method, which is called gel electrophoresis— a very fancy name—we were able to use on any organism at all. If you could grind it up, you could do it. That included people. I mean, you don't have to grind the whole person, but you could take a little bit of tissue or blood. Over the years a lot of data were gathered by anthropologists and geneticists, looking at blood group genes and protein genes and other kinds of genes from all over the world. I mean, anthropologists just went around taking blood out of everybody. I must say, if I were a South American Indian, I wouldn't have let them take my blood, but they did. And so, I thought, "Well, we've got enough of these data—let's see what it tells us about the differences between human groups." >> Lewington's findings were a milestone in the study of race and biology. >> If you put it all together—and we've now got that for proteins, for blood groups, and now, with DNA sequencing, we have it for DNA sequence differences— it always comes out the same: 85% of all the variation among human beings is between any two individuals within any local population: between individuals within Sweden or within the Chinese or the Kikuyu or the Icelanders. >> There just hasn't been time for the development of much genetic variation, except that which regulates some very superficial features like skin color and hair. For once the old cliché is true: under the skin we really are effectively the same, and we get fooled because some of the visual differences are quite noticeable. >> The superficial traits we use to construct race are recent variations. By the time they arose, important and complicated traits like speech, abstract thinking, even physical prowess, had already evolved. >> As geneticists, we now have the opportunity to investigate, using proper genomic analysis, complex human traits— athletic ability, musical ability, intelligence, all these wonderful traits that we wish we understood better, and for which we'd very much like to know if there are genes that are involved, how they interact, how they play out. Those traits are old. We spent most of our history as a species together in Africa, in small populations, before anyone left. >> Physical differences don't make race. What makes race are the laws and practices that affect life chances and opportunities based on those differences. Courts and legislators had long been in the business of conferring racial identities. In the [U.S.] South, to enforce Jim Crow segregation and laws against mixed marriages courts had to first determine who was Black under law. >> And here is where it really gets interesting. You got some places, for example, Virginia— Virginia law defined a Black person as a person with 1/16th African ancestry. Now, Florida defined a Black person as a person with 1/8th African ancestry. Alabama said you're Black if you have any Black ancestry— any African ancestry at all. But you know what this means? You can walk across a state line and literally, legally change race. Now, what does race mean under those circumstances? You give me the power, I can make you any race I want you to be because it is a social, political construction.