New discoveries in genetics
I have posted before about the "kludge" nature of evolution, and have also stated that scientists were going to find that genetics isn't so much a beautiful "code" as it is a hodge-podge of things that just happens to work well enough to get the job done, and that genetic engineering isn't going to be as much "engineering" as trying to pull one stick out of the bottom of a stack without wrecking the stack.
This story just confirms that idea a bit more.