This afternoon I heard Ronald Green, an ethicist from Dartmouth, give the 2006 Sims Lecture for the Poynter Center on the IU Bloomington campus. His topic was “Babies by Design? The Ethics of Gene Enhancement.” It was a good lecture, hitting most of the interesting questions regarding the possibility that at some point in the future, humans are going to be able to tinker with their own genetic makeup or even their own evolution. The most interesting area of discussion, and what I’m mostly focusing on below, is the area of germline changes (i.e., changes that affect not just the person receiving the treatment but his or her offspring), and in particular those that are aimed more at enhancing life rather than removing disease.
One of the questions afterward had to do with evolution, and what it would mean to take the “natural” out of natural selection. Green responded with a couple of points; for starters, we evolved for a different landscape from the one we’re in so perhaps it makes sense to adjust our genome to better suit our current environment. For example, we have in some sense adapted to food scarcity, so that abundance can be hard to live with and many people become obese. What if we could re-engineer our genome to remove the tendency toward obesity? This might be important especially because obesity doesn’t necessarily kill people before they reproduce, so I suspect the selection pressure against it is relatively small. What gives me pause is the possible unintended consequences, about which more below.
His other point stuck in my mind because it had just come up in a conversation with a friend. Evolution is about surviving long enough to reproduce, and so some of the things that matter to us don’t matter to evolution. Green added that maybe it wouldn’t be a bad thing to help evolution along and provide some of the things for ourselves that evolution doesn’t care about, like a healthier post-reproductive lifespan. He mentioned a cryptoreligious thread in discussions of evolution, the idea that our nature and our genome are given to us by God, and therefore sacred, something we should not tinker with. However, I don’t think you have to be religious or believe in God to feel deep reservations about the wisdom of changing our genome. What worries me is whether we have adequate knowledge and humility and foresight to do better than nature at creating ourselves–not because nature is sacred, but because of the complexity of the systems involved.
Obviously we intervene in nature all the time; I live in a climate-controlled building and wear glasses and take a calcium-channel blocker for hypertension, for example. But it’s obvious that in improving human life and rearranging nature more to our liking, we’ve damaged the natural systems we rely on for clean air, drinkable water, and livable weather, not to mention the toll we have taken on other species. We haven’t found a balance between improving our lives and living sensibly and sustainably within the bounds of the planet on which we depend. Given our cavalier and reckless treatment of the biosphere, why assume we would be any less short-sighted or selfish or ignorant when dealing with our genome?
Furthermore, even though the human body is far from perfect, the limitations we’d face in improving it are not that different from those faced by the evolutionary forces that created it in the first place over generations of compromises and contingencies, and we don’t yet understand very well the trade-offs and interactions that went into making us who we are. We’re not intelligently designed; we’re cobbled together out of whatever worked in previous generations, plus whatever was suboptimal but not bad enough to outright kill previous generations, plus a lot of things that don’t matter one way or another to evolution but arose as byproducts of something else. I sometimes think the human body is like a generations-long software project that has accreted all kinds of mysterious bits of code for which the purpose is not obvious. Things are connected in ways that are not clear; old structures or processes are pressed into performing new functions. The human body is in some ways an amazingly complicated Rube Goldberg contraption, and I don’t think we understand it nearly well enough to improve our genome significantly.
