If there’s any one paragraph that summarizes the thesis of this book, it is probably this:
Today, efforts to classify humanity have for the most part ceased. Scientists have finally realized that they were no more successful using blood groups, or other genetic markers, than they had been in the past when they were using skulls or skin color. They have finally realized that categorizing human beings into “races” requires such a distortion of the facts that its usefulness as a tool disappears. Simultaneously, the term “race” is disappearing from scientific writing because scientists no longer accept the clear cut division of humanity into white, black, yellow and red that is still present in most college curricula and textbooks. From a biological viewpoint, human races do not exist. This is a conclusion that most anthropologists and geneticists have accepted. Now they understand their task differently: to study human variability without the concept of race. It is also time for the rest of us to abandon this obsolete, destructive and false notion of race.
I don’t know how you’re going to react to this idea. I’m personally sympathetic to the concept. Indeed, I picked up this book because I already thought that races were sociological rather than biological in origin. Now, having read the book, I’m more convinced of it than ever. Biologically speaking, races only exist when populations live in isolation from one another long enough to develop genetically unique expressions, while retaining the ability to procreate with members of the other races of the same species. Despite thousands of years of folklore and pseudoscience to the contrary, this has never been the case for human populations. Our diversity is far greater on an individual basis than it has ever been on a group basis.
But I know some people won’t accept it. They’ll claim it is contrary to their common sense, which ultimately holds sway over us all, and they’ll reject any kind of evidence that goes against it. But if they dig a little more deeply into their understanding of biology and inheritance, they may find that much of their common sense on the subject is built on a bunch of false notions.
Like what? Well, how about the idea that blood plays a role in heredity. It’s a common expression—he’s got Irish blood flowing in his veins, for example—and it leads to the inexact concept that we somehow have the blood of our forebears in our bodies. But it has absolutely no basis in fact. Blood isn’t the mechanism of heredity, genes are. Every person’s body manufacturers its own blood, which is comprised of cells that are more-or-less identical to every other body’s blood cells, and there is no such thing as “Irish blood” or “African blood” or “Chinese blood.”
Unfortunately, this idea about blood being the medium for heredity is more than just word play.
However, one of the most disheartening and cruel consequences of the belief that blood was the carrier of heredity was the “one-drop” rule which was used for centuries in determining people’s ancestry. According to the blood theory of inheritance, as I mentioned previously, the blood of the parents was blended together to form the child; therefore, there was always a little of the blood of any ancestor flowing in one’s veins. If the ancestor were considered to be inferior in any respect, it was thought that his or her blood had tainted all of his or her descendants. For example, in Medieval Europe, people considered a person to be a Jew if he or she had a Jewish ancestor as far as six generations back. In the United States, people consider a person to be black, regardless of skin color, if he or she had a single black ancestor, no matter how far back that ancestor may have been. The “one-drop” rule persisted throughout World War II. It was this rule that the Nazis used to exterminate the Jews. To them, having one Jewish grandparent was enough to classify someone as Jewish and have him or her exterminated. It made no difference what the religions of the other grandparents were or what the religion of the individual was; the Nazis believed the blood of a Jewish ancestor tainted the victim. It was this idea that also led German authorities to prevent blood transfusion from Jews to non-Jews. Jewish physicians were reported to have been sent to concentration camps for having committed such a “crime.” In the mind of the Nazis, the physicians who did this had obviously tainted the blood of “Aryan” people.
That’s just one false idea that has had horrifying consequences. Another is the again false idea that we carry some piece of the genetic heritage of all of our ancestors. In fact, the only guarantee you have is that you carry on the genetic material of your two parents in some randomly selected quantity. You probably have something from your grandparents—but not necessarily—and as for your great-grandparents, the reality is much slimmer than you may imagine.
The reason why this is so is the same as the one which we gave for the fact that we are unique: the process of meiosis that occurs during the formation of sex cells. Though you can be sure you inherited twenty three chromosomes from each of your parents, you cannot know how many chromosomes you indirectly received from your grandparents. As you remember from our previous discussion of meiosis, your father had received from his own father twenty-three chromosomes that we have called paternal chromosomes and from his mother twenty-three chromosomes that we have called maternal chromosomes. However, because his sperm contains only one chromosome of each pair (which one is determined at random), any one of them can contain any combination of paternal and maternal chromosomes; any one of them could have received either fifteen paternal chromosomes and eight maternal chromosomes or thirteen maternal chromosomes and ten paternal chromosomes, to name just a couple of possibilities. It could happen that the sperm of your father which fertilized the egg of your mother that produced you had only one chromosome or no chromosome at all from your paternal grandfather. It is highly improbable, but it is possible. In the same way it could happen that the egg that produced you had one or no chromosome from your maternal grandmother. Nevertheless, we can assume that, on average, we received eleven or twelve chromosomes from each of our grandparents, that an average of fix or six came from our great grandparents, and average of two or three from our great-great-grandparents. With each generation further back, the average number of chromosomes we may have received from any ancestor is diminished by half. Consider now an important fact: Six generations back we have more ancestors than chromosomes (sixty-four versus forty-six). Hence, it is clear that the more remote our ancestor is, the greater the odds become that we did not received even a single one of his or her chromosomes.
It’s a bit complicated, but it all clearly derives from biological mechanisms and mathematics. Once you realize that the genetic material that gives you your biological identity can only be from as many as six generations back, you begin to realize how utterly impossible the idea of human races is outside of anything but a sociological perspective. No one, for example, can be half-white and half-black, because there is no such thing as black genes and white genes, black chromosomes and white chromosomes. It may be culturally important to someone that their great-great grandfather was a Cherokee Indian, but it is extraordinarily unlikely that it is biologically so.
But don’t take me or the book to mean that the concept of human races is culturally insignificant. Indeed, one of the most fascinating chapters of the book deals with the racial classifications determined and perpetuated by the U.S. government. There is no biological underpinning to the concept of race, but that hasn’t stopped humans from discriminating of the basis of skin color for hundreds if not thousands of years. The government’s racial classification system is essentially a tracking mechanism that is meant to give it the ability to respond to and correct instances of institutionalized “racial” discrimination. And that mission lends some credibility to its efforts.
But like all racial classification systems, theirs is equally flawed and subject to the widest interpretations. Plenty of people don’t fit neatly into one of the current five categories (White, Black, Hispanic, Asian or Pacific Islander, American Indian or Alaska Native), and many decisions based on demographic data based on those categories make little objective sense. It may surprise some, but creating a label for something that apparently exists, does not in fact bring that thing into actual existence. As a culture, we’ve understood this for a long time. It was the French naturalist Buffon who observed as early as 1750:
Genera, orders, classes exist only in our imagination … There are only individuals. Nature does not arrange her words in bunches, nor living beings in genera.
It is an observable fact. But, like human races, it runs counter to both common sense and generations of tradition. Few facts can withstand such a withering attack.