1 The Zero-Force Evolutionary Law 2 Randomness, Hierarchy, and Constraint 3 Diversity 4 Complexity 5 Evidence, Predictions, and Tests 6 Philosophical Foundations 7 Implications.

A common worry about the genetic engineering of human beings is that it will reduce human genetic diversity, creating a biological monoculture that could not only increase our susceptibility to disease but also hasten the extinction of our species. Thus far, however, the evolutionary implications of human genetic modification remain largely unexplored. In this paper, I consider whether the widespread use of genetic engineering technology is likely to narrow the present range of genetic variation, and if so, whether this would (...) in fact lead to the evolutionary harms that some authors envision. By examining the nature of biological variation and its relation to population immunity and evolvability, I show that not only will genetic engineering have a negligible impact on human genetic diversity, but also that it will be more likely to ensure rather than undermine the health and longevity of the human species. (shrink)

It is commonly believed that disability disqualifies people from full participation in or recognition by society. This view is rooted in eugenic logic, which tells us that our world would be a better place if disability could be eliminated. In opposition to this position, I argue that that disability is inherent in the human condition and consider the bioethical question of why we might want to conserve rather than eliminate disability from our shared world. To do so, I draw together (...) an eclectic, rather than systematic, configuration of counter-eugenic arguments for conserving disability. The idea of preserving intact, keeping alive, and even encouraging to flourish denoted by conserve suggests that disabilities would be better understood as benefits rather than deficits. I present, then, a reading of disability as a potentially generative resource rather than unequivocally restrictive liability. In other words, what I consider here is the cultural and material contributions disability offers to the world. (shrink)

The idea that a world in which everyone was born “perfect” would be a world in which something valuable was missing often comes up in debates about the ethics of technologies of prenatal testing and preimplantation genetic diagnosis . This thought plays an important role in the “disability critique” of prenatal testing. However, the idea that human genetic variation is an important good with significant benefits for society at large is also embraced by a wide range of figures writing in (...) the bioethics literature, including some who are notoriously hostile to the idea that we should not select against disability. By developing a number of thought experiments wherein we are to contemplate increasing genetic diversity from a lower baseline in order to secure this value, I argue that this powerful intuition is more problematic than is generally recognized, especially where the price of diversity is the well-being of particular individuals. (shrink)

New uses of preimplantation genetic diagnosis to screen embryos prior to transfer raise ethical, legal, and policy issues that deserve close attention. Extensions for medical purposes, such as to identify susceptibility genes, late onset disease, and human leukocyte antigen matching, are usually ethically acceptable. Whether embryo screening for gender, perfect pitch, or other non-medical characteristics are also acceptable depends upon the parental needs served and the harm posed to embryos, children, and society. Speculations about potential future uses of PGD should (...) not prevent otherwise acceptable current uses of PGD. (shrink)