woman had once
is
woman had once had for him was gone now, anyway.
"The thing is, Walter, that if the Mfecane worlds had remained isolated from the rest of the human race—say, maybe twenty more generations—they probably wouldn't have been part of the human species any longer. Not, at least, in the precise biological sense of the term 'species.' "
The scions of Erewhon's great families were highly educated, so Walter understood the point immediately. "Part of the same gene pool, able to interbreed. The variation had diverged that much? In such a short space of time? Those worlds were only isolated for a few centuries, as I recall."
As usual, an intellectual problem was enough to settle down Du Havel.
"Over a full millennium, actually," he said. "Their ancestors were almost as lunatic as the original Graysons, if for somewhat different reasons, and they set out about the same time and had less distance to travel."
The professor glanced around at the carnage, wincing. "Natural selection on those two planets was ferocious, Mr. Imbesi. I know a fair amount about the Mfecane worlds, as it happens, because they're one of the standard extreme cases used by theorists when we calculate the effects of genetic variation on political processes. The child mortality rate in the first few generations approached eighty percent. Worse than that, on Lieutenant Palane's home planet of Ndebele, which was the more extreme of the two environments. Combined with an isolated population, those are the classic conditions for rapid speciation. Plenty long enough, even leaving aside the genetic manipulations of the founding colonists. In fact, if the population had been one of simple animals, they probably would have become a separate gene pool. But that's always harder to manage, when the animals involved are intelligent. A lot harder. It's—ah—" He smiled, perhaps a bit ruefully. "The final step in speciation is always the development of a distinct set of mating rituals, and that's very hard to do with humans. We're just too bright not to be able to figure out how to screw around."
He examined Templeton's corpse again. "So, she's still human, in all that matters. Still part of the same gene pool—as Manpower proved by incorporating so much of the Mfecane genotype into some of their breeding stock. For that matter, I'm sure you've heard of Duchess Harrington?"
Both his listeners