Since the human genome has been mapped, we've heard all sorts of speculations, some useful, some not, about what this implies for the future. People may be denied insurance coverage because their genes showed health problems to come. Genes may be altered to correct "defects" like gender or non-preferred racial characteristics or mere "average" intelligence.
How long before we ordinary people are replaced by a new super-species of peaceful and beautiful winged humans with savant-level ability in all the major IQ categories? And what happens to human freedom if we can genetically eliminate the violence gene or the borrowing-without-permission gene or the trying-to-impeach-the-wrong-president gene?
OK, I'll admit I've done a bit of reductio ad absurdum here. But it didn't take that much reductio to reach absurdum.
First, remember that science reporting in America is sensationalistic, socially motivated, and usually wrong. Mapping the human genome, in and of itself, is a clerical operation. A complicated one, given the tools we have, and well worth doing, but nevertheless it is a matter of recording raw data.
When we think of mapping in the geographic sense, we assume that having the map means we know something of the terrain. There'll be a mountain here, a bay there; here there'll be desert, there swamp, and yonder is tundra.
The map of the genome, on the other hand, carries with it no automatic knowledge. It happens that we have already discovered some aspects of some functions of some regions of the genome. Mapping the rest of our DNA did not tell us one speck more about what each new part is used for. That will take many years of work by many scientists and in the end may never be fully accomplished.
That's because our chromosomes are not, in fact, codes. "Code" is merely a rough analogy, in our computer-happy age, for the way DNA seems to function as a data-storage system, so that "all" the information needed to create a human being can be combined from two sources and transferred into a new organism.
But the genome does not, in fact, contain what is needed to create a human being. DNA, which can be thought of as a protein-creating machine, doesn't go out and supervise how its proteins will be used. So it's useful to have a map of the genome. But now the real work begins: figuring out what, if anything, each section of DNA is used for--keeping in mind that some sections have multiple uses. Attributes we might want to alter may be caused by many different genes, and some of those genes may also be involved in other processes that we do not wish to change.
We're just beginning the journey, and, contrary to what you've heard, we do not have a map.
