Time Enough for Love (31 page)

“Oh, the deck isn’t bad, Captain; we’ve slept on the floor all our lives.” She yawned again, could not suppress it.

“Well…tomorrow we’ll make better arrangements.” (No, his cabin wouldn’t do; his desk was in here, and his papers and files. The kids would be in his way and he in theirs. Could he and Joe convert two narrow bunks into one double bed? Probably—although it would nearly fill one stateroom. No matter, that bulkhead between their rooms was not structural—cut a door and they would have a suite. A “bridal suite.” For a sweet bride. Yes.) He added, “Let’s get you to bed before you fall out of that chair. Everything’s going to be all right, dear.” (I’ll damned well see to it!) “And tomorrow night and from now on, you and Joe can sleep together in a wide bed.”

“Really? Oh, that would be”—she yawned again—“
lovely!
”

He had to steady her into her stateroom; she was asleep as she hit the bunk. Sheffield looked down at her, said softly, “Poor little kitten.” He leaned down and kissed her, went back to his cabin.

There he dug out everything the slave factor had offered as proof of the alleged odd genetic heritage of Llita and Joe, and gave each item intense study. He was looking for clues to truth or falsity of the allegation that they were “mirror twins”—complementary diploids having the same mother and father.

From such clues he hoped to estimate the probability of unfavorable gene reinforcement in any child Llita and Joe might have.

The problem seemed to divide into three (simplified) cases:

The two might be no relation to each other. Chance of a bad reinforcement: slight.

Or they might be the usual sort of brother and sister. Chance of bad reinforcement: too high to be ignored.

Or they might be (as alleged) zygotes resulting from complementary gametes—all genes conserved at reduction-division but with no duplication. In this case the chance of unfavorable reinforcement would be—what?

Let that wait. First assumption, that they were no relation but simply raised together from babyhood—no special hazard, forget it.

Second assumption, that they might be full siblings of the usual sort. Well, they did not look like it—but, more important, that scoundrel had set up a most elaborate “store” for such a swindle, and had used publicly the name of a bishop to back him up. The Bishop might be just as crooked (likely—he knew that priesthood too well!)—but why be so careless when slave babies were so cheap?

No, even if he assumed a swindle, there was no reason to expect an unnecessary risk in a setup so elaborate. So forget that, too: Llita and Joe were
not
sister and brother in the ordinary sense—although they might have shared the same host-mother’s womb. The latter, if true, was of no genetic significance.

So the remaining worry concerned the chance that the slave factor had told the truth—in which case what were the chances of a bad cross? How many ways could such artificially produced zygotes recombine unfavorably?

Sheffield tried to set up the problem while cursing the lack of sufficient data, plus the fact that the only real computer in the ship was the piloting computer, which could not be programmed for a genetics problem. He wished Libby were aboard. Andy would have stared at the bulkhead a few minutes, then come up with answers definite where possible and expressed in probability percentages where not.

A genetics problem, even with all pertinent data (many thousands!), was too unwieldly to solve without computer assistance.

Well, try some simplified illustrative problems and see what insight could be gained.

Primary assumption: Llita and Joe were “mirror twins”—genetically complementary zygotes from the same parent zygotes.

Control assumption: They were unrelated other than being part of the home planet’s gene pool. (An extreme assumption, as slaves from the same area were likely to derive from a much smaller gene pool, which might be still further reduced by inbreeding. But this “most favorable normal breeding pattern” was the correct control against which he must measure.)

Simplified example: Test one gene site—call it site 187 of the twenty-first chromosome—for reinforcement, masking, or elimination, of an assumed “bad” gene, under each assumption.

Arbitrary assumption: Since this site might hold an unfavorable gene—or two, or none—in its gene pair, assume that the chance was exactly the same for both primary and control assumptions, and even—
i.e.
, 25 percent no bad gene in the pair at the site, 50 percent one bad gene, 25 percent two bad genes—an extreme condition since, over the generations, reinforcement (two bad genes at one site) tended toward nonsurvival, either lethal or reducing a zygote’s ability to compete. Never mind; make it even for both of them—there were no data on which to base any better assumption.

Wups! If a bad reinforcement was visibly demonstrated, or could be shown by tests, such zygotes would
not
be used. A scientist competent to attempt this experiment would use specimens as “clean” in a genetic sense as possible—free of all the hundreds (thousands new?) of identifiable hereditary defects; the primary assumption should include this subsidiary assumption.

These young people were free of any defect Sheffield could detect in a shipboard examination—which enhanced the probability that this horsethief had told the truth and these exhibits were sober records of an exotic and successful experiment in gene manipulation.

Sheffield now tended to believe that the experiment had taken place—and wished that he had the resources of a major Howard Clinic, say the one on Secundus, to give these kids a genetic going-over that he was not equipped to do aboard ship and not qualified to do in any case.

One nagging doubt lay in how he had acquired these kids. Why had that gonif been so anxious to sell? If they were what the exhibits claimed? Why sell them when breeding the two created complements back together was the next step of the experiment?

Well, perhaps the kids knew but he had not asked the right questions. Certain it was that they had been brought up to believe that such was their proper destiny; whoever planned this had induced in the kids from earliest childhood a pair-bond stronger than most marriages, in Sheffield’s long experience. More than any of his own—(Except one, except one!)

Sheffield put it out of his mind and concentrated on the theoretical consequences.

At the selected site, each parent zygote had been assumed to have three possible states or gene-pairs in probability 25-50-25.

Under the control assumption, parents (diploid zygotes) both male and female would show this distribution at the selected site:

But under his modified primary assumption Sheffield assumed that the priest-scientist would discard bad stock as displayed in zygotes—which would eliminate the fourth group (“bad-bad”) and leave a parent-zygote distribution for this site of:

*

Such culling gave marked improvement over the original random-chance situation and meiotic division would produce gametes (both sperm and ova) in this incidence:

—but with no way to detect the bad genes without destroying the gametes carrying them. Or so Sheffield assumed, while stipulating that the assumption might not be true forever. But to protect Llita (and Joe) it was necessary that his assumptions be pessimistic within the limits of available data and knowledge—i.e., that a bad gene could be spotted only as reinforcement in a zygote.

Sheffield reminded himself that the situation was never as black-and-white as was implied by “good-dominant” and “bad-recessive”—these descriptions were less complex than the real world they were used to image. A characteristic exhibited by an adult zygote was prosurvival or contrasurvival only in terms of what and when and where—and also in terms of more than one generation. An adult who died saving its progeny had to be counted a prosurvival whereas a cat that ate her own young was contrasurvival no matter how long she lived.

In the same vein, a dominant gene sometimes was of no importance one way or the other—e.g., brown eyes. Just as its corresponding recessive when paired and thereby reinforced to produce blue eyes gave the zygote exhibiting it no measurable disadvantage. The same was true of many other inheritable characteristics—hair patterns, skin color, et cetera.

Nevertheless this description—good-dominant, bad-recessive—was in essence correct; it synopsized the mechanisms by which a race conserved its favorable mutations and destroyed (eventually) its unfavorable mutations. “Bad-dominant” was almost a contradiction in terms, as a thoroughly bad mutation which was dominant killed itself off (along with the unfortunate zygote inheriting it) in one generation, either lethal in womb or so damaging to the zygote that it failed to reproduce.

But the usual weeding process involved bad-recessives. These could remain in the gene pool until one of two events happened, each controlled by the blind laws of chance: Such a gene could pair with a gene like it when sperm fertilized ovum and thereby eliminate itself by eliminating the zygote—hopefully before birth, or—tragically—after birth. Or this bad-recessive might be eliminated by chromosome reduction at meiosis and the result would be a healthy baby who did
not
carry this bad gene in its gonads—a happy outcome.

Both these statistical processes slowly weeded out bad genes from the race’s gene pool.

Unfortunately the first of these processes often produced babies viable but so handicapped they needed help to stay alive—sometimes needing economic help, born losers, who never managed to support themselves; sometimes needing plastic surgery or endocrine therapy or other interventions or supports. When Captain Aaron Sheffield had been practicing medicine (on Ormuzd and under another name), he had gone through stages of increasing frustration over these poor unfortunates.

At first he had tried to practice therapy by the Hippocratic Oath—or close to it; he was by temperament unable to follow
any
man-made rule blindly.

Then he had had a period of temporary mental aberrance during which he had sought a political solution to what he saw as a great danger: reproduction by defectives. He tried to persuade his colleagues to refuse therapy to hereditary defectives unless they were sterile or sterilized or willing to accept being sterilized as a precondition for receiving therapy. Worse yet, he had attempted to include in the definition of “hereditary defective” those who displayed no stigmata save that they had never managed to be self-supporting—on a planet not overcrowded and which he himself had selected centuries earlier as nearly ideal for human beings.

He got nowhere, he encountered nothing but fury and contempt—save for a few colleagues who agreed with him privately and denounced him publicly. As for laymen, tar-and-feathers was the mildest medicine they prescribed for Dr. “Genocide.”

When his license to practice was lifted, Lazarus regained his normal emotional detachment. He shut up, realizing that grim old Mother Nature, red of tooth and claw, invariably punished damfools who tried to ignore Her or to repeal Her ordinances; he need not interfere.

So he moved and changed his name again and started to get ready to go off-planet—when a plague hit Ormuzd. He had shrugged and gone back to work, an unfrocked physician whose services were temporarily welcome. Two years and a quarter of a billion deaths later he was offered his license back—subject to good behavior.

He told them what to do with that license and left Ormuzd as quickly as possible, eleven year later. He was a professional gambler during that wait, that being the handiest way he could see at the time for saving up the necessary.

Sorry, Minerva, I was talking about those mirror twins. So the silly little wench was knocked up, which caused me to slip back into my baby-cotching, country-doctor
persona
, and I stayed up all night worrying about her and her brother and the baby they were going to have—unless I did something about it. To find out what I
should
do, I had to reconstruct what
had
happened and from that what
could
happen. Having no certain data, I had to follow that old rule for finding a lost mule.

First I had to think like that slave factor—A man who auctions slaves is a scoundrel but too smart to risk a caper in which he might wind up a slave himself, or dead if he was lucky—which is what would happen to one who played fast and loose on Blessed with the authority of a bishop. Ergo, the scoundrel had believed what he had said.

That being so, I could table the question of why this factor was commissioned to sell these two, while I tried to think like a priest-scientist engaged in human biological experimentation. Forget the chance that these two were ordinary siblings—no point in picking such a pair even for a swindle. Forget the chance that they were unrelated in any fashion, as in such a case it would simply be a normal case of breeding. Sure, sure, any woman can give birth to a monster, as even with the most genetically hygienic of breeding a bad mutation can show up—and an alert midwife may neglect to give that first life-giving spank—and many have.

So I considered only the third hypothesis: complementary diploids from the same parents. What would this experimenter do? What would
I
do?

I would use as near perfect stock as I could find and not start the experiment until I had both a male and a female parent who tested “clean” genetically in the most subtle ways for which I could test—which on Blessed meant quite sophisticated ways, for that century.