Historians had come along much later and developed their own vocabulary for telling the story of the succeeding five thousand years. The first pregnancies were called Gestations. Not counting the numerous miscarriages, there had been thirty-nine of them, distributed among the Seven Eves, before Camila, the last to stop bearing children, had finally gone through menopause. From these, thirty-five viable girls had resulted. Thirty-two had gone on to have children of their own. By then, Eve Moira had figured out how to synthesize Y chromosomes, and so some of the second generation had been male. The result, therefore, had been thirty-two Strains. Each of the seven new races had embodied more than one Strain. The Strains were recognizably different and yet clearly classifiable as belonging to one race or another, somewhat as East Africans differed from West Africans but still looked like Africans to Europeans.
“Correction” was the name given to the phase that had begun after the first round of Gestations, when Eve Moira had fixed errors that had led to several nonviable infants. In a sense, Correction went on continuously all through the first round of Gestations and began to taper off as the daughters of the Eves began to produce second-generation children. It faded into a next stage, Stabilization, which lasted through the following ten generations or so as Y chromosomes were patched up, lingering genetic mistakes were fixed, and members of different Strains began to interbreed to produce hybrids within their own racial groups. During this time the lessons of the black-footed ferret were put to use as various techniques were employed to increase heterozygosity.
In truth a vast library of human genetic sequences was available in digital form, and once they had survived the first few generations in Cradle, and trained hundreds of bright young people to be genetic engineers, they could, in theory, have resequenced the original human race from scratch. This was the sort of thing Eve Moira had done by synthesizing the first artificial Y chromosome. But it was not what they collectively chose to do. That choice was altogether cultural, not scientific. Decisions had been made in the Council of the Seven Eves. Races had been founded that were, by then, several generations old. They had begun to develop their own distinctive cultures. To undo those decisions by reverting to the “rootstock” human race was viewed almost as a kind of auto-genocide. The competition that had developed among the different races rendered it unthinkable. So the genetic records of rootstock humanity were put to work adding a healthy degree of heterozygosity back into the existing races, rather than trying to go backward.
Thus Stabilization, which had continued until about the twelfth generation, by which point even the Julian race had grown large enough to go on propagating through normal means without the need for lab-based adjustments.
Stabilization had blended into Propagation, the next phase generally recognized by historians, which was fairly self-explanatory: the descendants of the Seven Eves had continued to have sex with each other and make more babies. This had occupied much of the first half of the First Millennium and led to a condition of overcrowding so severe that it had made obligatory the formation of separate colonies away from Cradle. For there were other places, perhaps not quite so favored as Cleft, but still well suited for the building of new habitats. They had reached the point, by then, of being able to construct new machines for moving about in space. It was time. Or so insisted the descendants of the Four, who sensed that conditions had become inimical to them in the crowded precincts of Cradle. Camila had been frank about her strategy of making new humans well suited to life in confined spaces. She had succeeded in doing so. And once the early habitats of Cradle had grown crowded, her strategy had begun to look like a good one. Whether it was purely an expression of their own racial mythologies or a biological necessity, the Four had reached out and pioneered new habitats, at first in other locations on Cleft, later on other fragments of Peach Pit. The descendants of A?da had done likewise, sometimes cohabiting with the Four, more often going it alone.
It wasn’t so much that A?da had done things that couldn’t be undone as that she had said things that couldn’t be unsaid. In that sense her Curse had real effect. An individual A?dan of the Second Millennium was the product of a mixed-race culture that was more than a thousand years old. He or she had grown up with persons of all races, loving some and hating others, getting on well, perhaps, with certain Teklans and Moirans while getting into fights with certain A?dans. In terms of his or her own personal experiences, there was no reason to stick together with others of the same race. But each race did have an ineradicable narrative, by now encoded into a culture that had become ancient. The narrative of the A?dans was that their Eve had spawned not just one race but a “race of races,” a mosaic, as proof that her children could do all that those of the other Eves could, and more. And if you were a descendant of A?da, clearly endowed with genetic markers that she had chosen for that purpose, then the inexorable force of that narrative would drive you toward colonies populated largely or purely by other A?dans.