A Troublesome Inheritance: Genes, Race and Human History.
Christians who work in science, especially in the biological sciences, are often at pains to explain to other scientists and many of their Christian brethren how they reconcile their faith with their scientific worldview. When popular science writing conveys a distorted picture of science, it does not help the overarching issue of reconciliation of God's Book of Words with God's Book of Works. We are all familiar with the abuses of scientism in this regard, such as the fallacy of genetic determinism and the misuse of evolutionary science.
The new book by Nicholas Wade, A Troublesome Inheritance, is a troubling example of nonscience being used to bolster a bad idea. In particular, the book is a good illustration of the dangers of certain widespread misunderstandings about the science of evolution and genetics. Wade concludes that human evolution proceeded recently and divergently among "the three major races" and that such "genetic evolution" explains many behavioral differences, including, among other things, why Jews are smart and why western cultures are more technologically advanced than others.
In his review of human history, Wade claims that genetic changes were involved in major transitions. We are told, for example, that within the few centuries just prior to the Industrial Revolution, people in England genetically evolved to be less violent, more hardworking, and more trusting of government and strangers, while people in the Middle East remained largely tribal in their behaviors and Islamic civilization declined as a consequence. The proposed reason for this difference is that, in the Middle East, modern-state-compatible behaviors were not selected for because people lived under "largely predatory" regimes that "extract[ed] taxes from their citizens but provide[d] few services." How this circumstance was not true for medieval England is not clear, and of course the actual genes supposedly responsible for these changes are not identified.
In many parts of the book, what Wade claims to be a central concept is nicely refuted by his own writing. When it comes to the question of how many races there are, Wade usually refers to three or five "major races," and admits that it is possible to think of seven races. He even says, "the more DNA markers that are used ... the more subdivisions can be established in the human population." It is not clear why Wade does not see this as a fatal error in his overall thesis. He is absolutely correct that the number of races defined by genetics is indeterminate and that fact renders the concept of racial biology meaningless. Furthermore, if one were inclined to divide the human population into three groupings according to genetic distances ([F.sub.st]), they would not be Africans, Asians, and Europeans (as Wade says), but Africans, Australians, and everyone else, including everyone from Asia, the Americas, and Europe.
In his discussion of the genetics of populations, Wade follows a minimalist definition of evolution as an inherited change in allele frequencies in populations. Allele frequencies differ to various degrees among all populations, defined in any way one likes. Most people think of evolution as the mechanism by which new species arise from common ancestors (descent with modification), but this is emphatically not what Wade is talking about.
The fact that there is some extent of allelic frequency variation in the human population (though actually very little compared to other primates) does not in any way imply evolutionary changes leading to permanent divergence, which requires fixation of alleles in defined and usually isolated populations. For example, we know that chimpanzees and humans evolved from a common ancestor and that the differences between chimp and human behavior are understood to be genetically fixed and a result of evolution. From this, it follows--Wade tells us--that the differences in social behaviors between different human cultures are the result of genetic evolution too. But even Wade admits that none of the human allelic changes found between populations have become fixed; all of them are reversible, and they do not lead to permanent or significant alterations in the critical phenotype of any human population. The analogy to human/chimp evolution is scientifically absurd.
While it is true that Africans have some unique genetic polymorphisms (one of which was discovered by one of us (1)) and that the mutations allowing for malaria resistance and lactose tolerance in adults began as regional changes under strong selection, these examples of population-specific genetic alterations actually refute rather than support Wade's racially based evolutionary claims. Lactose tolerance began as local variants, but has spread over the globe, and is still spreading.
Among the most telling cases of self-refutation of Wade's hypothesis is the example he gives of African Americans losing the sickle cell trait SNP because malaria is no longer providing a strong selection pressure on this population. His example refutes the idea that Africans have undergone any sort of actual evolution, since within a very brief time span the proposed phenotypic segregation of Africans due to selection for the S allele in hemoglobin is being reversed. The same kind of malleability is true of many so-called racial features such as skin color and body shape.
Human populations have been on the move and intermixing for the past 50,000 years. While some human genetic isolates exist, they are rare and represent a tiny fraction of the total human population. Wade does admit that there exist some populations that he calls "admixed," such as the modern residents of Ethiopia who are genetically more European than African. But what he does not seem to understand is that all human populations are mixed--there are no genetically "pure" populations. The idea of a pure race is pure myth.
Wade speculates that Jews have undergone some kind of selection for genes conferring higher intelligence because some of them (actually the wrong ones) were bankers during the middle ages. Wade bases this absurd idea on a misunderstanding of the scientific literature. What the key paper actually showed was that by principal component analysis of 550,000 genetic markers, European Jews can be identified and differentiated from non-Jewish Europeans. (2) This does not mean that Jews differ in any allelic frequencies from other Europeans, only that familial relationships can be detected. It would be quite surprising if the results presented in the paper were not obtained, and they have nothing whatever to do with "evolution."
Despite being a respected science journalist, the author frequently fails to distinguish between scientific arguments based on data and conjectures that are not. Two examples illustrate this serious deficiency. Wade mentions and does not dispute the work of Richard Lewontin showing that there is less genetic variation between populations than between individuals regardless of what population they belong to. To counter this, Wade cites Sewall Wright, as quoted in a famous textbook. (3) The very same textbook clearly indicates that the total average human F is less than that of different villages within the Amazon tribe of the Yanomamo, confirming Lewontin's point. Neither the textbook's authors nor Wright disagreed with Lewontin's conclusions on the relative importance of genetic diversity within compared to between populations.
The use of pseudo-scientific arguments to advance philosophical and political agendas is quite familiar to most readers. From eugenics to social Darwinism to some of the antitheistic arguments of the new atheists, the name of science has been misused to cloak questionable ideas in a mantle of unassailable truth.
The Christian belief that all human beings are created equal in the image of God is a matter of faith and not a scientific statement; there is no scientific evidence to refute it.
(1) F. Crofts, G. N. Cosma, D. Currie, E. Taioli, P. Toniolo, S. J. Garte, "A Novel CYP1A1 Gene Polymorphism in African-Americans," Carcinogenesis 14, no. 9 (1993): 1729-31.
(2) A. C. Need, D. Kasperaviciute, E. T. Cirulli, D. B. Goldstein, "A Genome-Wide Genetic Signature of Jewish Ancestry Perfectly Separates Individuals with and without Full Jewish Ancestry in a Large Random Sample of European Americans," Genome Biology 10, no. 1 (2009): R7, doi:10.1186/gb-2009-10-1-r7.
(3) Daniel L. Hartl and Andrew G. Clark, Principles of Population Genetics, 3rd ed. (Sunderland, MA: Sinauer Associates, 1997).
Reviewed by Sy Garte, Scientific Director of the Natural Philosophy Institute (NPI) and Aniko Albert, Senior Researcher at the NPI, Rockville, MD 20851.
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|Publication:||Perspectives on Science and Christian Faith|
|Article Type:||Book review|
|Date:||Mar 1, 2015|
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