Something I’ve suspected for a long time.
One of my fundamental concerns about genetic engineering has always been my belief that the genetic code is considerably more complex and “kludged” than most people think. A change in one place could have many more effects than simply altering somebody’s eye color or something.
So far, the science is backing me up. Our genetic code is not a straightforward line-by-line “program,” but a mandala of instructions tacked onto other instructions, code modified and tweaked by hundreds of millions of years of nature’s code monkeys, simply routing around old routines instead of discarding them.
Evolution loves this setup. The longer it goes on, the easier it is to make major changes, since so many complex setups evolved over time have been “put in storage” and just switched off. Life began by taking almost three billion years for single celled life to evolve past microscopic forms, but in more recent eras organisms make amazing changes in far less time. It took about fifty million years to convert something that looked like a small deer into a blue whale.
The creationist metaphor is wrong. You don’t need to try to make a watch by shaking up all its random parts. You see, somewhere hidden in that pile of parts, there’s already most of a watch already assembled.
National Geographic did a piece on dog genetics. Apparently, due to humanity constantly screwing with their breeding over tens of thousands of years, dogs have apparently developed a hair-trigger genome that can create massive changes with very little tweaking.