Will Saletan of Slate gave this new blog a very gracious shout-out yesterday - many thanks. He also replied to my earlier post taking Will to task a bit about “designer dogs.” I’d suggested that dog breeding is a bad analogy to bring home the problems of genetic trait selection in humans, because the former is so familiar and non-threatening. Will replied that he used a familiar example on purpose, and wondered what other analogies might work better.

To answer that, it helps to think a bit about what’s troubling in the first place about genetic trait selection for people. Breeding dogs with 25-year-old frozen sperm from a former champion doesn’t quite get at what disturbs me about human trait selection. Some people already have done a version of the dog trick with the now-defunct “Nobel Prize sperm bank” - the moral equivalent of breeding a former dog show champion. The Nobel bank was creepy, but it remained something of a fringe practice, even though it offered an easy route to instant eugenics.

One reason it stayed a fringe phenomenon may have been the lack of control prospective parents had over the outcome. You couldn’t really be sure your Nobel offspring would be an Einstein, and the child might lack good looks and social graces altogether. The Nobel bank may have boosted the odds that your child would have the desired traits, but it still relied on old-fashioned, largely unsupervised egg-sperm unions.

Pre-implantation screening of traits gets you more control, and that kind of control is what worries me most. Babies should be a little surprising - as in, “Whoa, red hair! Where did that come from? Loves art - who knew?” Having a child has always meant opening yourself up to something new and unpredictable. But meticulously screening out the traits you don’t want would bring a level of control that the Nobel bank never offered.

Maybe gambling is a better analogy for the problem than designer dogs. Reproduction the old way amounted to an honest roll of the dice. Now the dice could be loaded to prevent novelty.

That idea doesn’t make me sick - sorry, Will - but it does violate my parental sense of fair play. And if children lose their power to surprise, it will drain a bit of wonder from the world.

William Saletan of Slate has a nice piece this week warning of recent developments that could bring genetically selected “designer babies” a step closer to reality. He begins by noting that the idea is so shopworn that he’d stopped taking it seriously - me, too. Then he goes on to list some studies and changing practices by certain fertility clinics that could be a prelude to selection for traits such as gender, eye color and hair color. None of the news items he mentions is scary on its own, but as a group they suggest something troubling is in the air.

Or that’s what I thought, until I read Will’s post the next day on “designer dogs.” Dogs are basically a designer species - living, drooling examples of eugenics in action. Without thousands of years of artificial selection by humans, dogs as we know them wouldn’t exist. To Will’s mind, dogs are “an ecologically reckless genetic experiment.”

He’s being a little facetious, but just a little. The piece goes on to lament the origins of this year’s winner of the Westminster Kennel Club dog show - a poodle conceived with frozen semen from a former champion dog. That use of standard reproductive technology to make the dead poodle a dad again proves too much - “I want to throw up,” Saletan writes.

Leon Kass has praised the “wisdom of repugnance” in thinking about bioethics, but in this case repugnance seems more silly than wise. Dog breeders have been using frozen sperm since the 1960s. As bioethical dilemmas go, it’s a Brave Old World.

Saletan wants to use dog breeding as an analogy for designer babies, but it may be hopelessly flawed for that purpose because it’s so familiar. Such comfortable examples are of little help in imagining how awful genetic trait selection in human babies would be.