“‘Geographically distant’ being the key phrase. In a less technologically advanced region like sub-Saharan Africa, travel is going to be limited. Wouldn’t that mean villages are going to be more genetically homogenous? We don’t have the luxury of hopping around Africa, picking up people from different tribes.”
“That’s true to an extent, but people who haven’t invented agriculture also tend to be nomadic. My guess is that you’d have better luck grabbing a bunch of people from a single African village than people from many different regions in a cultural nexus like Rome. But this is mainly academic. In the twenty-first century, studies showed that eighty-five percent of the variation in the overall human population on Earth was between individuals of the same population, with about fifteen percent of the variation occurring between populations.”
“Meaning what?”
“Meaning that it doesn’t make that much difference where you land. North America, Southeast Asia, Western Europe… anywhere you go, the genetic variation between the natives and the people on board Freedom is going to be about the same. It will be slightly higher in sub-Saharan Africa than elsewhere, but probably not enough to matter much. It won’t be enough, in any case. Even if we could ensure maximum genetic diversity and adequately screen for genetic defects, we will still run into a problem with genetic drift.”
“Explain.”
“There is a large element of chance in determining which gene variants—called alleles—get passed down to offspring from the parents. If an allele happens to get passed down less frequently than its competitors in a given population, there is a chance it will disappear entirely over time. This results in less genetic variation, which gives you the same problems as inbreeding: greater likelihood of defects.”
“I’m afraid I’m not following, Dr. Foley.”
“Think of it this way,” Foley said. “You have two hundred marbles in a jar, representing our two hundred colonists. Half of the marbles are red and half are blue, with each color corresponding to a different variant of one gene in the population.
“To represent reproduction, randomly select a marble from the original jar and deposit a new marble with the same color into a new jar. This is the ‘offspring’ of the original marble, meaning that the original marble remains in its jar. Repeat this process until there are two hundred new marbles in the second jar. The second jar will now contain two hundred ‘offspring,’ or marbles of various colors. Unless the second jar contains exactly one hundred red marbles and one hundred blue marbles, a shift has occurred in the allele frequencies.
“If this process is repeated a number of times, the numbers of red and blue marbles picked each generation will fluctuate. Sometimes a jar will have more red marbles than its ‘parent’ jar and sometimes more blue. This fluctuation is analogous to genetic drift–a change in the population’s allele frequency resulting from a random variation in the distribution of alleles from one generation to the next.
“The smaller the number of marbles in the starting jar, the greater the chances of an imbalance between red and blue occurring in a future generation. An imbalance in a small population is likely to become more pronounced in later generations, and there is a good chance that eventually that no marbles of one color or the other are chosen. If no red marbles are selected, the jar representing the new generation contains only blue offspring. Thus the red allele has been lost permanently in the population, while the remaining blue allele has become fixed: all future generations are entirely blue.
“Most such fixations are benign, but some will not be, particularly when combined with other fixations. Even with genetic screening, it is impossible to predict the effects of genetic drift over many generations. Over the course of sixteen generations, our originally healthy, diverse population may be reduced to a bunch of drooling imbeciles. And the effects of this genetic bottleneck will persist and worsen even if our defective descendants manage to colonize another planet. Fertility will decrease and additional defects will propagate. Even in an ideal environment, this branch of humanity would be unlikely to survive.”
“How do we avoid this problem, short of getting a bigger ship?”
“The most feasible solution? A sperm bank. Human sperm can be frozen indefinitely with little risk of genetic damage. The process of artificially inseminating humans is straightforward and easily understood, requiring almost no equipment. We will still need a core group of colonists, of course, who will be almost entirely female.”
Chapter Thirty-five
After getting some food and water, Akiva went with the captain and six of his men directly to a Jewish garrison in a nearby town. The foreigners, unbound but kept under constant watch, traveled with them. The garrison was a Roman fort that had been captured and repurposed. It seemed to house around three hundred men, although most were not present at the moment. Word of their encounter with the strange men was sent to Simon ben Kosevah, who was thought to be at his headquarters at Herodium. They slept the night at the garrison, and by the next morning word had arrived that they were to travel immediately to Herodium. Judging from the message received from Simon ben Kosevah, the rebel leader was as interested in meeting Akiva as he was in meeting the strangers. Akiva protested that he could not go to Herodium, as by now his wife must be apoplectic with worry. The captain, however, insisted that Simon’s commands were to be followed precisely. Akiva was assured that word would be sent to his wife.
They left for Herodium later that day, accompanied by ten additional soldiers. The captain did not want to risk any harm befalling either Akiva or the strangers. The strangers had been untied but relieved of their weapons; they were kept under constant watch. Akiva had reminded them that several times in the Torah God had prophesied through the mouths of the enemies of Israel. The strangers may have come to pronounce the coming of the moschiach, but that did not mean they were to be trusted. The captain, a cautious sort, agreed. They were treated well and given the same rations as the other men, but they were constantly under guard. No further attempt was made to ascertain their origin or their purpose in Judaea; by order of the captain, communications were limited to keeping the strangers fed and reasonably comfortable on the way to Herodium.
They arrived later that same evening. Eleazar of Modi’im greeted them in the courtyard of the fortress. “Akiva ben Yosef!” Eleazar cried, embracing the old man. “Is it true what they tell me? You have accepted that Simon ben Kosevah is the moschiach?” He spoke in Hebrew, which few of the men could understand, despite Simon ben Kosevah’s efforts to make it the official language of Judaea.
“I went into the desert to seek the counsel of the Lord,” Akiva said. “After three days, I saw a star falling over the sea. I followed it, and was led to these strangers, who spoke the name Simon bar Kochba.”
Eleazar regarded the three strangers, who stood a few paces away, surrounded by soldiers.
“Yet they speak no Aramaic?”
“Nor Hebrew, nor any other language I can identify.”
“Come then, we must speak with the Nasi at once. Bring the three strangers, but leave the others here.”
“It is not safe to bring the strangers to Simon alone. The Lord has used them to proclaim the moschiach, but we do not know their motivations.”
“The Nasi has nothing to fear from such men. He is the moschiach, chosen by God to lead his people to redemption. If the strangers mean him harm, God himself will strike them down.”
“Bring the captain, at least,” Akiva said. “He can tell attest to my story and tell us how he found the men.”
*****
So Eleazar escorted Akiva, the captain, and the three strangers to Simon’s quarters, where the rebel leader awaited them. Akiva fell to his knees before him.
“Arise, Akiva ben Yosef,” said Simon. “It is honor enough that you have come to this place. These are the three persons whose arrival was accompanied by a falling star?”
Eleazar helped Akiva to his feet. “Yes, Nasi. I have been una
ble to ascertain where they are from, but the tall one spoke the name Simon bar Kochba.”
“Who are you?” Simon said to the tall man. When this got no response, he repeated the question in Hebrew and then Greek.
The man seemed to understand Simon was asking his name. The man tapped his chest and said, “Jason.”
“Yeh-son,” said Simon. The man nodded.
“Where are you from, Yeh-son?”
The man spoke a string of non-words and pointed above him.
“Is he claiming to be an angel of heaven?” Simon asked.
“Forgive me, Nasi,” Akiva said. “I do not know.”
“Who am I?” Simon said, tapping his own chest.
The man hesitated. Then he said, “Simon bar Kochba.”
“Why do you call me this? ‘Son of a star?’”
The man gave no response.
“Do you come to proclaim me the moschiach of Israel?”
The man regarded the other two strangers, and the woman said something in their language.
“Moschiach,” said the tall man. “Simon bar Kochba.” He knelt before Simon, and the others did the same.
Simon turned to the captain. “Where did you find these men?” he asked.
“About three miles southwest of Rehovot,” he said. “Their clothes were damp, so we thought they might have been shipwrecked, but we could not communicate with them. We were about to execute them as Roman spies when the rabbi intervened. The tall one spoke the name Simon bar Kochba, as the rabbi said.”
Simon thought for a moment. “Akiva ben Yosef, I think we have taxed you enough for one day. Captain, take the rabbi and the strangers to Zechariah, who waits below in the courtyard. Instruct him to secure two rooms, one for the rabbi and one for the strangers. Make sure they have everything they need.”
“Yes, Nasi. Should the strangers’ room be placed under guard?”
“Leave one man at their door to attend to their needs.”
“Yes, Nasi.” He spoke to the three, and they nodded. They had picked up enough Aramaic on the trip over to follow some basic commands. They followed the captain out the door, and he closed the door behind them.
*****
“What do you make of it, Uncle?” asked Simon.
“The strangers seem frightened. Unsure of themselves.”
“You do not think they are heralds of God?”
“If they are, they seem unaware of it.”
“Akiva is convinced.”
“Indeed,” said Eleazar. “And that may prove to be of more worth to us than the strangers’ pronouncement itself.”
“My thoughts as well. What is the language they speak?”
“Amongst themselves they speak a Germanic tongue that is unfamiliar to me. But when they are trying to communicate with us, they use a variety of Latin.”
“Then you can understand them?”
“I understand some. Their fluency is very limited, and they speak with a strange accent. I thought it best not to let on how much I understood while Akiva was with us.”
“You are wise, Uncle. Do not let him speak with the strangers again. So far, he has been blinded to their uncertainty by his own fervor. He wishes fiercely to believe I am the moschiach, and nothing must be allowed to happen to disabuse him of the idea. Tomorrow, we will send Akiva back to Beneberak with a new mission: to declare among the people of Judaea that the moschiach has arrived.”
“And the strangers?”
“Watch them closely. They must not think we suspect anything, but make sure the guard posted to their door is capable and alert. They will not leave this fort.”
Chapter Thirty-six
“How many, uh, samples would this require?” Jason asked.
“To be safe?” Lauren Foley replied. “At least five hundred.”
“I see. And how many women?”
“We could make do with our current group, but it wouldn’t hurt to bolster our numbers a little. And I don’t mean just for the sake of genetic diversity. Keeping all those plants and animals alive is going to be a lot of work. We need more people, preferably some with real experience with agriculture and animal husbandry.”
“Give me some hard numbers.”
“A hundred more colonists, at least ninety of them female.”
“Do we need any male colonists at all?”
“For the purposes of reproduction or ensuring sufficient genetic diversity? No. Depending on gender roles of the local societies, we may need their expertise. For example, if women are forbidden to be involved in agriculture, they won’t have the knowledge we need to raise crops. But while I’m not a sociologist or historian, I think we’re unlikely to run into such a situation. In most societies that are stratified by gender, men monopolize hunting and leadership and military roles while women are left to cook, tend to young children and keep house. We have little use for the traditionally male roles and a great deal of need for traditionally female roles.”
“There weren’t many female shepherds in the Middle East.”
“True, although that was primarily due to the dangers of tending sheep alone, far from home. I don’t think you’d need to look far to find a woman with the knowledge to rear and care for sheep. However, there may be other male-dominated skills, not related to food production, that would come in handy now that we’ve dumped most of our equipment. Blacksmithing, metalworking, construction and woodworking come to mind. Even aboard Freedom, these skills would be useful, particularly if we have to do large-scale renovations to accommodate our new mission.”
“Skills can be learned,” Jason said. “And we have a huge library of instructional material in our data banks. Information, fortunately, doesn’t have much mass.”
“Agreed, although a single competent blacksmith is worth a terabyte of data on blacksmithing. We may find it worthwhile to bring a few male colonists on board if doing so will fill some obvious skill gaps.”
“It sounds like you would prefer to keep the group one hundred percent female if possible.”
“Wouldn’t you?” Foley asked with a smirk.
“I carry a recessive gene linked to epilepsy,” Jason said, smiling. “You don’t want my defective genes in your pool.”
“I’m sorry,” Foley said. “My intimation was unclear. What I meant was that from a management perspective, an all-female group would be preferable.”
“You’re saying that women are easier to control?”
Foley didn’t take the bait. “I’m saying, first of all, that a single-sex group is easier to manage than a mixed group. Second, there is a greater incidence of aggressive and noncompliant behavior among men than women. And third, there is greater statistical variation in mental health among men than women, meaning that you are more likely to have an extremely mentally ill person pop up among a male population than in a female population. In summary, if you want to avoid a situation in which an individual provokes a mutiny or builds a bomb to blow a gaping hole in the hull, you’re better off with an all-female population.”
“Which is not to say that a female won’t try to manipulate me into providing classified information by orchestrating a hostage situation.”
“There are always outliers,” Foley said with a shrug.
“In any case, the population won’t stay one hundred percent female for long. Assuming we keep the overall number of colonists steady, by the fourth generation it will be pretty evenly split.”
“Only if we don’t perform any additional sex selection.”
“What are you suggesting?”
“I’m not suggesting anything. I do, however, want to make something clear: our best chance to maintain genetic integrity long-term is continue to favor the propagation of females over males, for as long as the genetic bottleneck occurs—that is, until the colonists have reached their destination.”
“Why is that?”
“Think of it this way: assume we have fifty females for our initial group of colonists. For simplicity’s sake, assume there
are zero males aboard.”
“It would certainly simplify things for me if I weren’t on board,” Huiskamp said. “Why only fifty?”
“The age of the initial group is going to skew very young, so most of them will still be alive into the third and possibly the fourth generation. We’ve got a hard limit of two hundred people. If we aim for replacement population with each generation, we’re going to go over that limit if we start with more than fifty—unless some of the initial colonists have no children, in which case they’re just dead weight from a reproduction standpoint.”
“Understood. Proceed.”
“With zero males aboard at first, all the mothers will have to become pregnant through artificial insemination from a donor to the sperm bank. Assuming normal sex distribution, if each colonist has one child, the second generation will be twenty-five males and twenty-five females. Fast-forward twenty years. The second generation is now ready to reproduce, but now we’ve only got twenty-five females, so each female has to have twice as many children to keep the population up. The presence of siblings in the second generation means less genetic diversity. That’s one problem.
“The other is this: each female of child-bearing age now has a choice. She can either become pregnant by one of the donors to the sperm bank or by one of the male colonists. If we have gametes from five hundred unrelated donors in the sperm bank, then we still have four hundred and fifty packets of new genetic material in the sperm bank. So the choice is either to introduce a new set of genes from the sperm bank or to use a set of genes that are already present in our population of colonists. The obvious choice, to ensure the health of future offspring, is to use the sperm bank. But that means that the males already in the population serve no purpose, in terms of reproduction. They are dead weight, at least until each set of DNA in the sperm bank has been used. That’s about ten generations. And once you start using donors from within the population, quality begins to decline, so that even DNA from the sperm bank that has been used once continues to be a better option in most cases.
The Legacy of the Iron Dragon: An Alternate History Viking Epic Page 24
