This article in Business Insider explains how biochemists have created a tool that enables them to cut out a particular piece of DNA in human cells and replaced it with another one.
“Great!” we think. Now we can repair defective DNA, curing all kinds of diseases.
There are two problems with this thinking.
One is that the DNA is “defective”. Evolution works by random mutations, and what appears to be ‘defective’ may actually be a step towards something better.
The other is that DNA is not a machine. We are not machines. And (as you can read in this article) even though it has become “common sense to think that genes encode everything from our hair color to our propensity for wearing rubber bands on our wrists,” what evolutionary biologists are actually finding is that hair colour (and all the rest) actually depend on a “series of complex networked relationships at multiple levels ranging from individual “letters” in the genome to protein-gene networks to interaction networks between organisms.” This demonstrates “that our genes are only our destinies to the extent that they link to each other and to the surrounding world—both social and natural.”
In other words, cutting and splicing sections of DNA will have unintended consequences that go beyond our understanding. There will be unintended consequences.
We have the potential to create disastrous outcomes. And as Nassim Taleb has said and written, when the risk is infinite, our tolerance for that risk should be zero.