Vacation time, and I’m — well, never “catching up,” but let’s just say I’m doing more reading than I usually am able to do.

And I just read Greg Bear’s Darwin’s Radio, a horrifying science fiction story about a speciation event in humans. Briefly, the idea is this: mixed in among the “junk DNA” in the human genome are gene-ish blocks of DNA that either prevent or allow large-scale modifications of the genotype; occasionally some set of external conditions trigger the activation of this DNA code; with the result that a (sub-)speciation event occurs. (Picture something of the sort envisioned at the end of the last ice-age when — in this scenario — Neanderthals began to have “deformed” (i.e., cro-magnon) babies.

Not that I’m an expert, but from what I remember of biology, the “standard” Darwinian model of evolution is that variations occur within a population, and from time to time some of these variations are selected for or against by environmental circumstances. Finches with small beaks occasionally hatch a baby-finch with a long beak, and if the flowers or bugs or whatever it is that finches eat are just right, then those babies will tend to live long enough to mate and pass on their long-beaked genes to their own offspring etc.

The key point is to look at how those changes occur. In the standard model I learned back when, the idea was that the changes were totally random. The base pairs in the DNA used to code for this protein, but a cosmic ray came by, zapped mom or dad, and now it codes for this other protein. Most of the time, this new protein doesn’t exist, or it exists but doesn’t do anything useful, and the offspring dies. But once in a while the protein happens to produce something useful — a longer beak — and then you get more finches surviving, and over time the population is shot through with long beaks, and then some kind of crisis occurs with the result that they can no longer interbreed.

What Bear has done in Darwin’s Radio is to assume that these changes (long-beak or short) are not utterly random. Instead, this notional “control DNA” in the genotype already exists, and hangs out there as “junk DNA,” but when it wants to, it can exert control over the non-junk DNA. Virii do something similar: they take over the reproductive apparatus of a cell and cause it to make copies not of its own DNA but of the virus’. In the same way, this control DNA might sit there indefinitely, being copied along with the rest of the DNA, but from time to time, in response to some external condition, it would take over the copying and cause the non-junk DNA to be altered.

So. What might that look like? Bear has an idea, but I won’t spoil it. To give you an idea, however, suppose that suddenly, women all over the globe began having babies with dark skin, eyes with epicanthic folds like Asians, blue irises and blond hair. That is, something that was clearly odd. Since it was happening all over, among people none of whom exhibited these same characteristics, it would argue against it being the result of normal combination of genes to produce an unusual phenotype. That is, putative fathers might suspect bastardy, but the mothers would know better, and when it happened enough, around the world, the fathers might come to realize that they really were the fathers of the babies.

I called the book “horrifying.” What makes it horrifying? First, he postulates how the science around such a crisis would be politicized. Duh. Global warming would have nothing on this, because nobody really cares if the average temperature goes up 2 degrees. Not like they care if they are having mutant babies, at least. Secondly, it raises the question: what is the obligation of the parents to the babies? Of the race as a whole to itself? Are we the slaves of our DNA?

Are we obligated to rear as our own children that are not “us” — not only not our own, but not even “human?” We feel no obligation to allow virii to subvert our biology to make copies of themselves, do we? And yet, if human women, as a result of a similar overtaking of the reproductive apparatus, began giving birth to feature-complete chimpanzee-lookalikes, would we be obligated to treat them as human children? And if you say no, then what about humans with Down’s Syndrome? Where is the dividing line? What are the ethical principles it derives from?