at least some chemical processes have moral significance even if we don't, currently, understand how it arises
Moral significance is not a fact about morally significant humans. It's a fact about the other humans who view them as morally significant.
Our brains' moral reasoning doesn't know about, or depend on, the chemical implementations of morally significant humans' bodies. Therefore there are no moral questions about chemistry, including human biochemistry.
The original quote is correct: DNA should not be held sacred; DNA-related therapy is a tool like any biological or medical procedure. It has no moral status, and should not be assigned qualities like sacredness. Only specific applications of tools have moral status.
As I said, morality is in the eye of the beholder; one might therefore think it's possible to assign moral status to anything one wishes. However, assigning moral status to tools, methods, nonspecific operations, generally leads to repugnant conclusions and/or contradictions. Some people nevertheless say certain tools are immoral in their eyes. Other people value e.g. logical consistency higher than moral instincts. It's a matter of choice.
Our brains' moral reasoning doesn't know about, or depend on, the chemical implementations of morally significant humans' bodies. Therefore there are no moral questions about chemistry, including human biochemistry.
I suspect that, if I propose to drip an unknown liquid into your eyes, you will find the question of its chemistry very morally significant indeed.
Since our morality is embedded in, and arises from, physics, the moral questions are indeed at some level about chemistry even if the current black-box reasoning we use has no idea how to deal wit...
Here's the new thread for posting quotes, with the usual rules: