Enhancing Humans, Controlling Evolution

In December 2008, a study group convened by Rockefeller University published a commentary in Nature recommending societal adoption of cognitive-enhancing medications by healthy persons. The group included a prominent bioethicist, John Harris, who for two decades has recommended various enhancements--pharmacological, hormonal, chemical, genetic--as beneficial to human beings. Harris's most systematic defense of enhancements, including germ line and embryo enhancements, is presented in his very provocative book, Enhancing Evolution: The Ethical Case for Making Better People. The biotech revolution has brought us to a point where the human species, Harris contends, "will replace natural selection with deliberate selection, Darwinian evolution with 'enhancement evolution'" (p. 4). Harris initiates his argument with a thought experiment: Given the lengths many parents will go to seek the best educational opportunities and social advantages for their children, why not instead achieve the desired qualities--such as enhanced intelligence, better health and fitness, and improved physical and mental capacities--through such means as genetic engineering, regenerative medicine, reproductive technology, or nanotechnology, particularly by selecting for traits in the human embryo? In either context, Harris suggests, our goals are the same. We have simply changed from social engineering to genetic or pharmacological means. Once we have willed the ends, we have necessarily willed the means to realize those ends.