Hybrids (15 page)

“This,” said Vissan, placing a pale green device on the table in her cabin, “is the prototype codon writer.”

Mary looked at the machine. It was about the size and shape of three loaves of bread, placed end to end—although no Neanderthal would ever think of it that way.

“It can synthesize any string of deoxyribonucleic acid, or ribonucleic acid, if you prefer, as well as the additional proteins needed to manufacture chromosomes or other structures.”

Mary shook her head in wonder. “It’s a life factory.” She looked at Vissan. “In my world, you would have won the Nobel Prize for this—our top honor for scientific work.”

“But here,” said Vissan, “it is banned.” Her voice was bitter. “My intentions were so benign.”

Mary frowned. “What
were
your intentions?”

Vissan was quiet for a moment. “I have a younger brother who lives in an institution.” She looked at Mary. “We have eliminated most inheritable genetic disorders, but there are still things that can go wrong, things that are genetic but not inherited. My brother has—I don’t know what you call it. He has an extra chromosome twenty-two.”

“Chromosome twenty-one, you mean,” said Mary. Then: “No, of course you don’t. It
would
be number twenty-two here. We call that Down syndrome.”

“Are the symptoms the same in Gliksins?” asked Vissan. “Mental and physical feebleness?”

Mary nodded. But Down also caused facial abnormalities in Gliksins, including a protruding tongue, a slack jaw, and epicanthic folds even in occidentals. Mary wondered what a Barast with Down syndrome would look like.

“My mother was a member of generation 140. She should have had her first child when she was twenty years old, but failed to conceive then—or when she was thirty. She had me when she was forty, and my brother Lanamar when she was fifty.”

“Conceptions that late in life increase the likelihood of Down in my people, too,” said Mary.

“Because the body’s ability to produce clean sets of chromosomes has deteriorated. I wanted to overcome that—and I did. My codon writer could have eliminated all copying errors, all—”

“All what?” said Mary.

“I’m sorry,” said Christine. “I don’t know how to translate the word Vissan has used. It refers to when there are three chromosomes where there should only be a pair.”

“Trisomy,” supplied Mary.

“Had my parents had access to such technology,” continued Vissan, “letting them output a perfect diploid set of chromosomes despite their age, Lanamar would be normal. And, of course, there are a host of similar conditions that also could be avoided.”

Indeed there are
, thought Mary. One in 500 Gliksin children were born with a sex-chromosome difficulty, such as Klinefelter syndrome (two or more X chromosomes and a Y, or often a mosaic), triple-X syndrome, Turner syndrome (a single X chromosome either completely lacking a mate or with a truncated second sex chromosome), or XYY syndrome, which could predispose males to violence—she suspected Cornelius Ruskin had an extra Y; he certainly had the body type and personality. Other combinations occurred, but they mostly resulted in miscarriages.

“But that’s not all,” said Vissan. “Preventing trisomy and similar disorders was only the initial impetus for my work. Once I got into my research, other wondrous possibilities occurred to me.”

“Yes?” said Ponter.

“Yes, indeed! I wanted to eliminate the randomness in gene selection, leaving the choices of traits up to the parents.”

“How do you mean?” asked Ponter.

Vissan looked at him. “You inherited a bunch of traits from your father and another bunch from your mother; half of your deoxyribonucleic acid came from each of them, and in total, those two halves make up your forty-eight chromosomes. But each sperm you produce has a random selection of all those traits. You—Ponter Boddit—have DNA that contains both your father’s contribution to your eye color and your mother’s, plus your father’s contribution to your hair color and your mother’s, your father’s contribution to your browridge shape and your mother’s, and so on. But your sperm contain only twenty-four chromosomes, with just half your deoxyribonucleic acid. Any given sperm you make will contain
either
your father’s contribution to a given trait or your mother’s, but not both. One sperm might contain your mother’s contribution to eye color, your father’s to hair color, and your mother’s to browridge shape. Another might have exactly the opposite combination. A third might contain only your mother’s contributions to those things. A fourth, only your father’s. And so on, for all the tens of thousands of different genes you possess. No two sperm you ever produced will likely have the same combination of traits coded into it. The same sort of thing happens in the production of eggs, and, again, it’s a virtual certainty that no two eggs share the same combination of the mother’s mother’s genetic material and the mother’s father’s genetic material.”

“All right,” said Ponter.

“In fact—Mega here is your daughter, right?”

“Yes, I am!” said Mega.

Vissan crouched down to be at Mega’s face height. “Now, she has brown eyes, whereas you have golden ones,” said Vissan. “Do you have any other children?”

“An older daughter, named Jasmel.”

“And what color are Jasmel’s eyes?”

“The same as mine.”

“She’s so lucky!” said Mega, pouting.

“Indeed she is,” said Vissan, rising and patting the girl on her head. She looked at Ponter. “Brown is dominant; golden is recessive. The chances of a child of yours inheriting your eye color through natural processes were one in four. But if you’d let the codon writer output your genetic material for you, you could have chosen to give both your children golden eyes—or any other trait you or your woman-mate carried the genetic code for.”

“Aww,” said Mega. “I wish I had golden eyes!”

“Understand?” said Vissan. “What happens in a natural conception is that a set of traits selected entirely at random ends up being combined together.”

Ponter nodded.

“But don’t you see?” said Vissan. “That’s a crazy way to do it! An absolute gamble as to what you are going to get. And it doesn’t have to be related to things as inconsequential as eye color. You possess two genes related to the flexibility of the lens in your eye: one from your mother, and one from your father. Say the one you got from your mother is a good one that lets you see without corrective eyewear well into old age, but the one you got from your father is a bad one that would require you to use corrective eyewear from childhood. You will pass one, and only one, of those two on to your own offspring. Which would you choose?”

“My mother’s one, of course,” said Ponter.

“Exactly! But, in natural conception, there is
no
choice—no choice at all. It’s pure luck of the draw which one your child will get…because you let inefficient nature produce your sperm. But if we sequenced your deoxyribonucleic acid, we could choose the better one of each pair of traits you yourself had inherited, and then we could manufacture a haploid set of chromosomes containing only those better traits. We could also do the same thing with Mary, here, producing a haploid set representing only the better traits from her repertoire. And then we could combine them together to produce the best child you could possibly have. The child would still absolutely be one-half its father genetically and one-half its mother, but it would have the best possible combination of their respective genetic material.”

“Wow,” said Mary, shaking her head. “It’s not quite designer babies, but…”

Vissan shook her head. “No, although that’s technically possible with the codon writer, too: we
could
code in alleles that are present in neither parent. But that was never my intention. Generation 149 is to be conceived shortly—and I wanted it to be the greatest generation ever, bringing forth all the positive characteristics of the people who begat it, but none of the negative ones.” She shook her head again, and her tone grew even lower than normal. “It could have done as much to improve our species as the purging of the gene pool did.” After a moment, though, she seemed able to push her bitterness aside, at least temporarily. “That will never be, apparently. But at least the two of you can benefit from this capability.”

Mary felt as though her heart were going to burst. She was going to be a mother! It was really going to happen. “This is
fabulous
, Vissan. Thank you! Can you show us how it works?”

“Certainly,” she said. “I hope its batteries are still charged…” She touched a control, and a moment later a square screen came to life in the center of the unit. “Of course, you can attach a bigger display. Anyway, you pour appropriate raw chemicals into this aperture here.” She pointed to a hole on the right side of the unit. “And the output comes out here, suspended in pure water.” She indicated a spigot at the left end. “Obviously, you’ll want to hook it up to appropriate sterilized glassware.”

“And how do you specify the output?” asked Mary, staring at the machine in fascination.

“One way is by voice,” said Vissan. She pulled out a control bud and addressed the device. “Produce a string of deoxyribonucleic acid 100,000 nucleotides long, consisting of the codon adenine-cytosine-thymine over and over again.” She looked at Mary. “That’s the code for the amino acid—”

“For threonine,” said Mary.

Vissan nodded. “Exactly.”

Several green lights appeared on the device. “Ah, there—it’s saying it needs to be fed raw materials.” She pointed to the screen. “See? They’re specified here. Anyway, you can also use one of several keypads to input data.” She pointed at a toggle switch. “You select either deoxyribonucleic-acid or ribonucleic-acid mode here. And then you can input data at any level of resolution, right down to individual nucleotides.” She indicated a square arrangement of four buttons.

Mary nodded. The toggle must have been set for DNA mode, since the buttons were displaying the Neanderthal glyphs for adenine, guanine, thymine, and cytosine. She pointed to another cluster of buttons, arranged in an eight-by-eight grid. “And these must be for specifying codons, right?” Codons were the words of the genetic language, and there were sixty-four of them, each consisting of three nucleotides. Each codon specified one of the twenty amino acids that are used to make proteins. Since there were more codons than there were amino acids, multiple codons meant the same thing—genetic synonyms.

“Yes, that’s right,” said Vissan. “Those buttons let you choose codons. Or, if you do not care which codon is used to specify a given amino acid, you can just select the amino acid by name here.” She pointed at a cluster of twenty buttons, arrayed in four lines of five.

“Of course,” continued Vissan, “these controls are normally only used for fine editing; it would be incredibly tedious to specify a lengthy deoxyribonucleic-acid sequence by hand. Normally, one interfaces this device to a computer and simply downloads the genetic design one wishes to manufacture.”

“Amazing,” said Mary. “You wouldn’t believe the gyrations we go through to do gene splicing.” She looked at Vissan. “Thank you.”

“My pleasure,” said Vissan. “Now, let’s get down to work.”

“Now?” said Mary.

“Of course. We won’t produce the actual DNA, but we’ll get the process set up. First, we’ll take samples of your deoxyribonucleic acid and Ponter’s, and then sequence them.”

“You can do that here?”

“The codon writer can. We just feed in a sample of deoxyribonucleic acid, and let it analyze it. It should take about a daytenth for each specimen.”

“Only a daytenth to sequence an entire personal genome?” said Mary, astonished.

“Yes,” said Vissan. “Let’s get it started, and then I’ll go catch us something to eat.”

“I’d be glad to help in the hunt,” said Ponter. He smiled and raised a hand. “Although I know you don’t need it.”

“I would welcome the company,” said Vissan. “But first, let’s collect some genetic material from each of you…”

Ponter called the travel-cube driver and told him to head back to Kraldak; they would summon another cube later in the day to take them home.

Mary and Mega stayed back in the cabin, while Vissan and Ponter went off hunting. Mega showed Mary how her new toy worked; Mary paraphrased part of Kipling’s
The Jungle Book
for Mega; and Mega taught Mary to sing a short Neanderthal song. It was a kick spending time with Mega—and Mary knew it would be even more wonderful to have a child of her own.

Finally, Vissan and Ponter returned with a pheasant they’d caught for dinner, which Vissan proceeded to cook while Ponter made a salad. It turned out there were solar panels on the roof of Vissan’s cabin, and she had a vacuum box for storing food, an electric heater, some luciferin lamps, and more; friends had given her farewell gifts when she’d chosen to leave structured Neanderthal society. All in all, Mary thought it actually might not be that bad a life, as long as one had plenty to read. Vissan showed Mary her datapad, and how she could recharge it from the solar array on the cabin’s roof. “I have some four billion words of text stored on this,” she said. “My access to new works has been cut off, of course—but that’s all right; the new stuff is all garbage, anyway. But the classics!” Vissan hugged the little device to her chest. “How I love reading the classics!”

Mary smiled. Vissan sounded just like Colm, extolling the virtues of Shakespeare and his contemporaries; she’d had to keep her Harlequin romances out of his sight, lest an argument ensue.

The dinner was delicious, Mary had to admit—or maybe, she reflected, she was just famished after all the hiking she’d done that day.

The codon writer had been moved to the floor during dinner, but once they’d finished eating, Vissan lifted it back up onto the table. Mega curled up in a corner and had a nap, while the three adults sat around the table: Vissan on the one chair, Ponter on the end of a log, and Mary, facing the cyclopean mammoth skull, perched atop the vacuum box.

“All right,” said Vissan, peering at the display. “It’s finished sequencing.” Mary was looking at Vissan, rather than the square screen, since, with a few exceptions that she’d picked up along the way, she couldn’t understand the glyphs it was showing. But Vissan was oblivious to that, and pointed at the screen. “As you can see, it’s made a list of the 50,000 active genes in your deoxyribonucleic acid, Mare, and the 50,000 in Ponter’s.”

“Fifty thousand?” said Mary. “I thought there were only 35,000 active genes in human DNA. That’s our latest count.”

Vissan frowned. “Ah, well, you’re missing out on…I’m not sure what you call it. A kind of exonic redoubling. I can show you later how that works.”

“Please,” said Mary, fascinated.

“In any event, the device has now made a list of 50,000 gene alleles you each possess. That means the codon writer could now just go ahead and produce what you need: a pair of gametes that have the same number of chromosomes. But…”

“Yes?” said Mary.

“Well, I told you the original intention of this device: to let parents pick and choose from the alleles they could offer a child.”

“I think we’ll be happy to just try our luck randomly.” The words were out before Mary really had time to think about them; perhaps, she realized, it was some of her natural Catholic revulsion at tinkering with the stuff of life coming to the surface…although
any
use of this machine certainly qualified as major tinkering!

Vissan frowned. “If you were both Barasts, I would be content to accept that answer—but then again, as you yourself observed, Mare, if you were both Barast, you wouldn’t need the codon writer just to randomly combine your genetic material.” She shook her head. “But you are not both Barasts.” She looked down at Ponter’s forearm. “I never thought I’d use one of these again, but…Companion of Ponter!”

“Healthy day,” said a male voice from the device’s external speaker. “My name is Hak.”

“Hak, then,” said Vissan. “Surely studies have been done of the differences between Barasts and Gliksin deoxyribonucleic acid since contact was made with Mare’s people?”

“Oh, yes,” said Hak. “It has been quite the hot topic.”

“Are those studies available through the planetary information network?”

“Of course.”

“Good,” said Vissan. “We will need to access them as we go along.” She looked up and shifted her gaze from Mary to Ponter, then back to Mary again. “I strongly advise against just slapping your deoxyribonucleic acid together. We are talking about combining two species here. Now, yes”—she gestured at the codon writer’s screen—“it’s clear that the genomes for Barasts and Gliksins are almost identical, but we should really examine where they diverge, and carefully select combinations.” She pointed at Mary. “Are tiny noses like that typical of your species?”

Mary nodded.

“Well, there, you see? It would be ridiculous to code for a tiny Gliksin nose and a giant Barast olfactory bulb. Traits should be chosen with care so that they enhance, or at least do not interfere with, each other.”

Mary nodded. “Right. Of course.” Butterflies were pirouetting in her stomach, but she tried to sound jaunty. “So, what’s on the menu?”

“Hak?” said Vissan.

“The genetic divergence—”

“Wait!” said Vissan. “I haven’t asked you a question yet.”

Ponter smiled. “Hak is a very intelligent Companion,” he said. “Do you know Kobast Ganst?”

“The artificial-intelligence researcher?” said Vissan. “I know
of
him.”

“Well,” said Ponter, “about ten months ago, he upgraded my Companion. You weren’t the only one trying to improve the lot of Barasts, of course. Kobast wants everyone in generation 149 to have the benefit of truly intelligent Companions.”

“Well, let’s hope they don’t shut Ganst’s work down as well—although if they do, I’ll be happy to have a neighbor. In any event, I was about to ask Hak to summarize what is known about how the Gliksin genome differs from the Barast one.”

“And I was about to tell you,” said Hak, sounding slightly miffed. “There are, as you observed, about 50,000 active genes in any Gliksin or Barast. But 98.7% of those have allele forms that exist in both populations; only 462 genes have forms that exist in Barasts but not in Gliksin, or vice versa.”

“Fine,” said Vissan. She looked at Mary. “You can leave the rest to chance, if you like, but I really think we should carefully look at those 462 genes, and make sensible choices for each of them.”

Mary looked at Ponter, to see if he had any objection. “That’s fine,” she said.

“All right—although, before we start, there are two big questions we must resolve. With the codon writer, we will make a diploid set of chromosomes combining deoxyribonucleic acid from both of you. Do we make twenty-three pairs of chromosomes, or twenty-four? That is, at the level of the chromosome count, do you want your child to be a Barast or a Gliksin?”

“Wow,” said Mary. “That’s a good question. The work I did in my world was about defining which species a person belongs to for immigration purposes. It seems likely that chromosome count will be adopted as the legal standard.”

“Your child can be a hybrid in many ways,” said Vissan. “But in this, it must be one or the other.”

“Um, gee…Ponter?”

“You are the geneticist, Mare. I rather suspect that matters of chromosome count are—how would you put it?—‘nearer and dearer to your heart’ than they are to mine.”

“You don’t have a preference?”

“Not on an emotional level, no. I suspect, though, that there are legal advantages to making our child genetically Gliksin.”

“How so?”

“We have a unified world government—the High Gray Council. You have 191 member states in your United Nations, plus some more besides that are not members, and immigration issues will arise with each of them, no?”

Mary nodded.

“It seems easier to convince one world government that a being with twenty-three pairs of chromosomes should be able to live and work anywhere in my world than it will be to convince some 200 governments in your world that a being with twenty-four pairs of chromosomes should be accorded the same rights.”

Mary looked at Vissan. “We’re not actually going to manufacture the DNA for our child today, right?”

“No, no, of course not. That will be done back in your world, I presume, when you are ready to become pregnant. I am just taking you through the issues you must deal with.”

“So we don’t have to decide right now.”

“That is correct.”

“Well, then, let’s table that one.”

Vissan looked at the table in front of her. “Pardon?”

“I mean, let’s set it aside for now. What’s next?”

“Well, this has nothing to do with your special circumstances but must also be decided, since it affects how the codon writer apportions Ponter’s deoxyribonucleic acid. Do you want a boy or a girl?”

“We’ve already discussed that,” said Mary. “We’re going to have a daughter.”

Vissan touched a control on the codon writer. “A girl it is,” she said. “Now, let’s see what else we’ve got…” She looked at the display.

“The next gene sequence displayed,” said Hak, “refers to hair part. Barasts have a natural part along the centerline of the scalp, right above the sagittal suture. Gliksins tend to have natural parts off to the sides. Mary seems to have alleles only for side parts; both alleles from Ponter’s personal genome are, of course, for center parts. You could take one of each, and discover experimentally which is dominant, or you could take both of Ponter’s and neither of Mare’s, or both of Mare’s and neither of Ponter’s, and be reasonably sure of the outcome.”

Mary looked at Ponter. The Neanderthals did indeed part their hair like bonobo chimpanzees. At first she’d found it quite startling, but she’d since gotten used to it. “I don’t know.”

“The side,” said Ponter. “If she is going to be a girl, she should take after her mother.”

“Are you sure?” asked Mary.

“Of course.”

“The side then,” said Mary. “Use both of my alleles.”

“Done,” said Vissan, touching some more controls. She indicated the square display. “You see how it’s done? These touch-points on the screen select alleles?”

Mary nodded. “Quite straightforward.”

“Thank you,” said Vissan. “I worked hard to make it easy to use. Now, I recognize the next group of alleles, at least on Ponter’s side: they are for eye color. Mare, your eyes are blue—something we never see here. Ponter’s are a golden brown shade we call
delint
; it is uncommon, but prized all the more because of that.”

“Blue eyes are recessive in Gliksins,” said Mary.

“As are
delint
here. So we can either take both your alleles, and make your daughter blue-eyed, both of Ponter’s and make her golden-eyed, or throw in one of each and be surprised by the outcome…”

They continued on in that vein for quite some time, interrupted only by Mary, then Ponter, having to take bathroom breaks—meaning using a wooden chamber pot.

“And now,” said Vissan, “we come to an interesting neurological item. I’d be very reluctant to take one of Mare’s alleles and one of Ponter’s at this point, since we just don’t know what effect mixing them at this site will have. I think it would be much safer for the child to go all one way or all the other, rather than try to blend the characteristics. In a Barast, this gene is well known for governing development of the part of the brain’s parietal lobe that is located in the left hemisphere. You surely don’t want to risk brain damage, and—”

“Did you say the parietal lobe?” said Mary, leaning forward. Her heart was pounding.

“Yes,” said Vissan. “Now, if that doesn’t form properly, aphasia can result, as can difficulties with motor function, so—”

Mary turned on Ponter. “Did you put her up to this?”

“I beg your pardon?” said Ponter.

“Come on, Ponter. The part of the parietal lobe in the left hemisphere!”

Ponter frowned. “Yes?”

“It’s what Veronica Shannon said is responsible for religious thinking in my kind of people. The out-of-body experience; the sense of being at one with the universe. All of that is rooted there.”

“Oh,” said Ponter. “Right.”

“You mean to say you didn’t know this was going to come up?”

“Honestly, Mare, I had no idea.”

Mary looked away. “You’ve been talking about a ‘cure’ for religion, for Pete’s sake. And now, lo and behold, we have one.”

“Mare,” said Vissan, “Ponter and I did not discuss this in advance.”

“No? You were alone together hunting long enough…”

“Really, Mare,” said Vissan, “I am not aware of the research you mentioned.”

Mary took a deep breath, then let it out very slowly. “I’m sorry,” she said at last. “I should know better. Ponter would never blindside me.”

Ponter’s Companion bleeped, but he didn’t ask for an explanation.

Mary reached out with her left hand. “Ponter, you
are
my man-mate, even if we haven’t yet undergone the bonding ceremony. I know you would never deceive me.”

Ponter said nothing.

Mary shook her head. “I didn’t expect to have to face this issue. I mean, eye color and hair color, sure. But atheist or believer? Who’d have thought that that would be a genetic choice?”

Ponter squeezed Mary’s hand. “This issue is far more significant to you than it is to me. I understand that much, at least. We will do whatever you wish.”

Mary took another deep breath. She could talk it over with Father Caldicott, she supposed—but, geez, a Roman Catholic priest wouldn’t approve of
any
part of this process. “I’m not blind, you know,” said Mary. “I’ve seen how peaceful this world of yours is, at least most of the time. And I’ve seen how…” She trailed off, thought for a moment, then shrugged, finding no better word than the one that had first occurred to her “…how
spiritual
your people are. And I keep thinking about all the things you’ve said, Ponter—back at Reuben’s place, when we watched that Roman Catholic Mass together on TV, and at the Vietnam veterans’ wall, and…” She shrugged again. “I
have
been listening, but…”