So here is my understanding of what Slicer wants to ask me: "You said there are limits to what we should permit in relation to Designer Babies - what are those limits?"
Firstly, let me be very clear as to the context of the 4thought.tv piece. The topic under discussion was the selection of IVF embryos for the purposes of a/ avoiding major genetic disease and b/ acting as a donor for existing children to treat (or even cure) their genetic disease. This process involves creating quite a number of embryos, most of which will (statistically) be unsuitable to be reimplanted into the womb in order to proceed to an established pregnancy. This discussion was not about changing the genetic state of any of these embryos - merely selecting from a wider pool than is normally available. Here, in 2012, this is what the term "Designer Babies" means. Not a great term, but there you go.
Now that's all very well, but Slicer is wanting to broaden this to incorporate a different sort of scenario - he wants to know about changing the genetic status of embryos. I've said there are limits, and I have no problem in saying that at the moment, I am very much not in favour of altering the germline of embryos - in effect creating genetically modified humans. Is this a set-in-stone ethical principle - that we should never alter the germline of humans? No it's not. My opposition to modifying the human germline is based on the dangers posed, given our current technology and understanding of genetics, and the fact that it is nearly always unnecessary - simple pre-implantation can nearly always do the required job. But if someone comes up with a great plan, and reasons why these objections should be set aside, I would look at their proposal.
And this goes back to the point I raised on the other thread, which is that morality and ethics are about helping humans make better decisions. That's what they're for. There are no timeless categories of "ethical" or "unethical" - these are labels we attach to decisions, based on the axioms we front-load our system with. But those axioms are not unchallengeable, and need checking. Very often they are heuristics, and even when they are very good heuristics, they need to be unpacked before we resort to a knee-jerk decision. But I digress.
So I've mentioned that I think a decision to use genetic technology to alter the human germline would qualify as unethical. Briefly, my reasoning is that the dangers associated with this (and I explicitly include potential social dangers, like creating a perceived "genetic underclass", regardless of how real the actual "underclassiness" of such a group would be) outweigh the potential benefits right here right now. I refuse to legislate for the future, because this is about helping us make decisions, not wag the finger.
But Slicer might want to accuse me of unnecessarily broadening the debate - what if we simply used selection to "enhance" the genepool itself. This would not alter any particular germline, but would leave an effect for the future. And here he might have a point. Is there a slippery slope towards selecting for babies with certain hair colour or eye colour or "intelligence" (whatever that is - this is 2012, and we haven't a bloody clue what genes are involved here) or pro-social behaviour or what have you? Would this be unethical?
Well, here's the problem. Let's suppose Slicey (or anyone) came up with a proposal to "enhance" the human race by selecting embryos, or even by selective breeding (I think someone tried this a few decades ago - I vaguely recall the whole project came to a sticky end for reasons other than its scientific vapidity) - Shaney is sitting on the Research Ethics Committee and is trying to make a determination as to whether this project should be allowed to proceed.
There are a number of problems. Firstly, I would not like to be told by a researcher of Slicey's stature who I should mate with (or not) - I am quite capable of making my own decisions in this arena, thank you very much. Secondly, the criteria that Slicey regards as desirable may not match my criteria. I'm a shortarse dark-haired dark-eyed dark(ish)-skinned chappie - not exactly the Aryan ideal - and my ideas for what might constitute a worthwhile goal for directed human evolution is perhaps different from Slicey's (although better guitarists - we would agree on that). Thirdly, I am not at all clear on how Slicey plans to measure the desired characteristic, either at the genetic level (in the embryos he wants to play with) or in the phenotypic outworkings of that in the population.
Fourthly, the old law of unintended consequences kicks in here - if these features were so brilliant, why has evolution not equipped us with them already? Perhaps you can (at a population level) have too much of a good thing. What if you selected for gene variant ZIPPY1.c.18302C>T, which is associated with high intelligence (I have made this up, repeat, I have made this up), only to find that in combination with BUNGLE2.c.937A>G it causes severe autism?
Number 5 (our list is by no means exhaustive - we're just trying to throw Slicey a few morsels to wrap his maw around): if we're looking to make changes to the genepool as a genepool (rather than just trying to do the best for our kids, and let the genepool look after itself), we already know from evolution that these things tend to take quite a long time when compared with the lifetimes of individuals. It's pretty likely that technology and proclivities will have changed by the time we arrive at our "goal", even if that goal is well defined - and I'm not sure that Slicey can even do that.
And then to close off with a number 6: one of the strengths of the human species as it sits right now, with this rather diverse (although in comparison with other species, still quite restricted) genepool is that we are potentially prepared for a change in our environmental circumstances which may not be foreseen. Usually this means disease. The old and discredited notion of eugenics necessarily involves further restriction on the genepool, which is potentially a bad thing for "the species", as variants that might have conferred resistance to the threat may have been removed by well-meaning (!) but misguided eugenic inheritors of the mantle of Slicey (in his role as proposing this).
So there you go, just for starters - a few real actual solid reasons why I, in my decision-making role as President of the World, would turn down Slicey's nefarious proposal, and if you want, you can distil those down to specific ethical principles which are drummed into every medical student.
Modern genetic technology gives us great power, but with great power should come great insight into the fact that we're still only scratching the surface, and the ramifications of going off half-cocked on some crazy genepoolscaping exercise suggest that we would all be a lot better off if we limit "designing our babies" to significant medical conditions, and not mere preference. This may end up being a bit too wishy-washy for some people who prefer a rule-based methodology, but I suggest that this approach is how we have to tackle difficult ethical scenarios thrown up by inexorable medical advance. I have to deal with patients, issues and decisions like these at the sharp end - I don't have the luxury of sitting in a committee with a rubber stamp, rolling back on the heuristics of the past.