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Beyond Genetics
The User's Guide to DNA
Chapter One
Bits and Genes
Humans have been thinking about heredity for as long as they have had to eat. The domestication of animals involved both the elimination of weaker cattle and the use of selective breeding. Herds in Africa were built, as early as recorded history, on what appeared to be the "better born" animals, whether they were sheep, goats, oxen, or camels.
Assyrian records indicate that as early as 5,000 B.C. crops were manipulated one by one through a process that would today be called artificial fertilization: the deliberate replacement of the typical activities of sexual reproduction with other activities, often odd in their execution, with the goal of making reproduction more efficient or improving its outcome. For example, the date palm never really had a chance to have normal reproduction, because date palm trees didn't produce delicious dates; people wanted dates that tasted better and came to fruition more quickly.
Before humans had any big theories about genetics, the manipulation of animals and plants became an important part of economic growth. Politicians made choices that changed the world of genetics perhaps as much as tens of thousands of years of evolution did. Some species suddenly got a wide berth -- became sacred, or became fashionable as something that humans liked to eat, have as pets, or wear -- while other species didn't fit into someone's long-term plans and were destroyed entirely, clear-cut from everything but the fossil records.
Heredity has also always been an "issue" throughout human history. Mostly, the issue has been that people -- typically entire cultures -- decided that some heritable trait was undesirable and have noticed that this trait might be inherited.
The people who do not inherit whatever it is that is undesirable define what it means to be born healthy in the view of the culture, and their health can qualify them for special treatment. The better the family tree, the better the social standing. Few cultures in Western or Eastern history of the past four thousand years have failed to hold up some group as biologically privileged. Only members of the tribe of Levi could inherit the Jewish priesthood. Hindu castes are built entirely around heredity. Most Native American tribes hold or have held that tribal integrity hangs on the restriction of intertribal marriages. To this day earnings and power in the United States can be highly correlated with inherited traits and the stigma or status associated with them. Most of the world now knows of the Raelian religion, which holds that cloning of human beings is the key to eternal life, and that Jesus, a UFO denizen, was himself a clone.
But the power of genetics, from 1600-2000 A.D., has come almost entirely from crude guesses about what will be desirable, resulting in crude changes in human activity, from the transplanting offish, bushes, and trees (Kudzu, anyone?) to marriage customs and genocide.
The guesses that people make about how genes work can be expressed as formal, even mathematical, propositions. But every guess comes laden with political and environmental implications, and so everyfight about how to think about a gene is also afight about ethics. If a scientist hypothesizes that the inheritance of a gene could make someone smart or criminal or tall or beautiful, it is a safe bet that the debate about how to use that gene will be hotly contested.
Genes can be tools -- to make better medicine or to repress the impoverished. They can offer new options or (through DNA fingerprinting) exonerate those who have been falsely accused of wrongdoing. What gives genes their power, then, are the values or ethics used to apply them: the decision made by individuals and society about how genes fit in to the desire to live a good life. Ethics involves making choices, and where genes are concerned, some choices are better than others, depending on where you stand. The question is, who decides how to put value on genes.
What Counts as Family?
Western theories of human heredity werefirst recorded in the Greek doctrine that asserted that sperm carries hereditary information and "vital heat" from father to offspring. The sperm was thought to direct the form of the baby. Aristotle disputed the notion that females had the vital heat necessary to contribute to the form of the offspring, and also held that traits acquired by parents during their lifetime might be passed to offspring. These early ideas contributed to "big theories" about genetics.
The theory that experiences acquired during life could be passed to offspring helped Greeks account for strange differences in appearance among parents and children. For example, Aristotle postulated that a child whose eye color differed from that of both parents must have acquired the trait from parental experiences. As a big theory of inheritance, Aristotle's was crude but politically effective for persuading parents to be careful before and during pregnancy. As a bonus, the achievements of the great could pass on to their children. Aristotle's big theory did have the disadvantage, as did many others of that time, of being wrong.
The real explosion in the study of the biological family dates only to 1800. Advancing right alongside is the practical power to effect changes in families. Western populations think of themselves as in control over what a "family" means, and the family is thus the subject of almost all literature since 1850, according to such varied critics as Jean Bethke Elshtain and Cecelia Tichi. We talk about a concept called social and biological identity of offspring, a notion forged through years of habitual behaviors by families, courts, and physicians about what counts as a family, what counts as inheritance, and what parts of maturation and development are most important.
Beyond Genetics
The User's Guide to DNA. Copyright © by Glenn McGee. Reprinted by permission of HarperCollins Publishers, Inc. All rights reserved. Available now wherever books are sold.
