I've been reading Jeffrey Eugenides's novel, Middlesex, the plot of which revolves around a rogue recessive gene afloat in a family's gene pool. When circumstances lead to the gene's expression -- well, the title is a clue to the result.
Which leads me in the middle of the night -- the book on the floor by the bed -- to those nattering thoughts that bother every parent now and then, especially parents who are well beyond the first sexy flush of procreation and looking back on a passel of children and grandchildren flowing out like a river from what at the time was a happy-go-lucky mixing of genes.
Who knows what variant genes are hiding in the pool, for generations perhaps, waiting for the right moments to express themselves? How many unwelcome genes would be necessary before we would forego reproduction? What would be the odds of a genetic surprise before we would be too frightened to take the chance?
Natural selection will work over the long haul to keep the odds in favor of the continuation of the species. Meanwhile, cultural taboos against consanguineous interbreeding help keep recessive anomalous genes in check. Yes, I know that parental love will embrace every child, no matter how difficult certain genetic flukes might be for the child or parents. But still the dark thoughts come, the apprehension that lurks like a shadow behind the biological imperative.
The day of the $10,000 sequenced genome is not so far away, and designer genes will not be far behind. The moral and social implications are almost too monumental to think about. How will we as a society balance the desire for whatever kind of child is deemed most desirable against the horrendous prospect of a species that diverges into the genetically-enhanced rich and the roll-of-the-genetic-dice poor?