Misconceptions persist because of the belief that biological races exist in anatomically modern humans. Here are some of the common examples. Races differ in intellectual ability, morality and temperament. Races differ in athletic abilities. Races differ in sexual appetites, in particular that blacks are hypersexual. Races have specific diseases, thus membership in race with predict an individual's disease predisposition. Again, this is inconsistent with what we know about the genetic variation in humans, so if we apportion human genetic diversity there are 86% shared in all world populations. Every population in the world has these genes, but may have them at different frequency. Of these, 10% are unique to a given continent, and 4% are unique to a specific local population. People have said to me, 'Professor Graves, that means that if you have 4% that are unique to a specific population, couldn't you use those 4% to identify a race?' I said, yes, if you want to do it that way; you could. But that would mean that we've got about 2000 races in the human species because you can identify these 4% of rare alleles to specific geographical regions. What's the point in identifying any of them if you have so many? You would have races by every hilltop, every valley, every divide in a river. At that level, the whole idea breaks down.
Polymorphic genes are genes that vary in frequency. These are the genes that everybody does not have in common. These are genes that occur at loci where no single gene or allele has a frequency of greater of 99%. Some of the ones that have been best studied are disease, like phenylketonuria, Tay-Sachs disease, cystic fibrosis, and sickle cell anemia. A map showing the frequency of the allele for cystic fibrosis shows that it differs in various portions of Europe. There are four things that maintain these polymorphisms.
*The first is called balancing selection. That is also called heterozygous advantage. This explains sickle sell anemia. Though the origin of this allele is uncertain, we do know that it is distributed at high frequency in groups that have been anthropologically described Negroid, but also groups that have been described as anthropologically Caucasoid. There are high frequencies of the sickle cell allele in Western Africa, but also in the Middle East and in the Mediterranean and in India. The only reason we think that sickle cell is a black disease is because the slaves imported to North America came from Western Africa. If they had come from the Mediterranean, if they had been Greek, they would come from the Middle East, or if they had come from India, Americans would have been describing sickle cell anemia as an Indian disease or a Yemen disease or whatever. It is not a racially identified disease. It has to do with the presence or absence of malaria. For example, Kenyans, who live at high altitude, do not exhibit any sickle cell because the mosquitoes that carry malaria do not live at high altitude, so you do not find it there.
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