It seems that we are on the verge of a revolution in genetic engineering. It is now possible to alter DNA, including human DNA. Thus I am confounded by the thought that future humans will be much more intelligent than I am, and better in every other way also. Which brings up the question, what do we know about DNA?
DNA is extremely complex, and we know of no life that does not contain DNA. Presumably, it came into being at almost the same time as life on earth began. The primary known function of DNA is to code for proteins. Proteins themselves are fabulously complex, not only in their chemical formulae and bonds, but also in how they fold into convoluted shapes. The shapes of proteins are essential to their function as they use a sort of “lock-and-key” mechanism to latch onto other proteins to do their work. All of this is astounding and if it were the only function of DNA (as was originally assumed) it would be wondrous indeed.
But only some of DNA codes for proteins, and the rest has always been called junk DNA. Curiously, the more complex a species, the higher the percentage of junk its DNA contains. Human DNA is said to be 98% junk, while simple bacteria DNA contains only 2% junk. Given how much we don’t know, all of these numbers are subject to change.
More recently it has been discovered that some junk DNA does have a function, which is to act as a sort of on-off switching mechanism to guide the development of developing embryos. To me, this is just as amazing as coding to synthesize proteins, because the DNA is telling the developing embryo when and where to develop brain cells, bone cells, or others kinds of cells, and how to put it it all together and configure a human being, or other life form.
But that still leaves more than 50% of human DNA as useless “junk”. The word “hubris“ comes to mind, so I propose another hypothesis.
What if this truly dark DNA is preprogrammed to guide evolution? What if this dark DNA acts to switch on selected evolutionary advances at appropriate times and places? Perhaps the junk DNA contains information that will be needed in the future to develop new organs, body plans and functions. And perhaps this junk DNA guides developing embryos on when and where to change, mutate or modify their behavior. Sounds fantastic. But DNA IS fantastic. We don’t know completely how major evolutionary developments happen, but maybe junk DNA has something to with it.