Darwin's Children Part 37

"Lars can always be relied upon to keep these sessions lively," Cross said.

"I'm hoping Dr. Nilson will ask equally probing questions of Kaye," Jackson said.

"Count on it," Nilson said dryly. "We realize how difficult it is to work with early-stage embryos in mammals, mice for example, and how much more difficult it is to work with primates and simians. As far as I have been able to review, your lab techniques have been creative and skilled."

"Thank you," Kaye said.

Nilson waved this off with another frown. "We also know that there are many ways in which embryos and their hosts, their mothers, work together to prevent rejection of the paternal components of embryonic tissues. Isn't it possible that by removing known ERVs in chimpanzee embryos, you have also shut down genes crucial to these other protective functions? I am thinking in particular of FasL, triggered by CRH, corticotropin releasing hormone, in the pregnant female. FasL causes cell death in maternal lymphocytes as they move in to attack the embryo. It is essential to getting born."

"FasL is unaffected by our work," Kaye said. "Dr. Elizabeth Cantrera, my colleague, spent a year proving that FasL and all other known protective genes remain intact and active after we knock out ERVs. In fact, we're tracking the possibility now that a LINE element transactivated by the pregnancy hormone in fact regulates FasL."

"I do not see that in your references," Nilson said.

"We published three papers in PNAS. PNAS." Kaye gave him the citations, and Nilson patiently wrote them down. "The immunosuppressive function of particles derived from endogenous retroviruses is indisputably part of an embryo's protective armament. We've proven that over and over."

"I'm concerned in particular about evidence that a drop in corticotropin releasing hormone after pregnancy induces rapid expression of ERV responsible for triggering arthritis and multiple sclerosis," Nilson said. "The ERV in this case are reacting to a sharp drop drop in hormones, not a rise, and they appear to cause disease." in hormones, not a rise, and they appear to cause disease."

"Interesting," Cross said. "Dr. Rafelson?"

"It's a reasonable hypothesis. The triggering of autoimmune disorders by ERV is a rich area for research. Such expression could be regulated by stress-related hormones, and that would explain the role such hormones-and stress in general-play in such disorders."

"Then which is it, Dr. Rafelson?" Nilson asked, his eyes sharp upon her. "Good virus, or bad virus?"

"Like everything else in nature, one or the other or even both, depending on the circ.u.mstances," Kaye said. "Pregnancy is a tough time for both the infant and the mother."

Cross turned to Sharon Morgenstern. "Dr. Morgenstern showed me some of her questions earlier," she said. "They are cogent. They are in fact excellent."

Morgenstern leaned forward and looked at Kaye and Liz. "I will state up front that although I often agree with Dr. Nilson, I do not find Dr. Rafelson's laboratory procedures free from bias or error. I suspect that Dr. Rafelson came here to prove that something could not not be done, not that it be done, not that it could could be done. And now we are supposed to believe that she has proven that embryos cannot proceed to live birth, or even grow to p.u.b.escence, without a full complement of old viruses in their genes. In short, working backwards, she is trying to prove a controversial theory of virus-based evolution that could conceivably elevate the social status of her own daughter. I am suspicious when such strong emotional motivations are involved in a scientist's work." be done. And now we are supposed to believe that she has proven that embryos cannot proceed to live birth, or even grow to p.u.b.escence, without a full complement of old viruses in their genes. In short, working backwards, she is trying to prove a controversial theory of virus-based evolution that could conceivably elevate the social status of her own daughter. I am suspicious when such strong emotional motivations are involved in a scientist's work."

"Do you have a specific criticism?" Cross asked mildly.

"A number of them, actually," Morgenstern said. Liz handed Kaye a note. Kaye looked over the quickly scrawled message. Morgenstern published twenty papers with Jackson over the last five years. She's his contact on the Americol jury. Morgenstern published twenty papers with Jackson over the last five years. She's his contact on the Americol jury.

Kaye looked up and stuffed the note in her coat's side pocket.

"My first doubt-," Morgenstern continued.

This was the true beginning of the frontal a.s.sault. All that had come before was just the softening up. Kaye swallowed and tried to relax her neck muscles. She thought of Stella, far across the continent, wasting her time in a school run by bigots. And Mitch, driving to rejoin an old lover and colleague on a dig in the middle of nowhere.

For one very bad moment, Kaye felt she was about to lose everything, all at once. But she drew herself up, caught Cross's gaze, and focused on Morgenstern's stream of precisely phrased, mind-numbing technicalities.

20.

OREGON.

They had left the dirt road twenty minutes ago and Mitch still had not seen anything compelling. The game was beginning to wear. He slammed on the brakes and the old truck creaked on its shocks, swayed for a moment, then stalled out. He opened the door and mopped his forehead with a paper towel from the roll he kept under his front seat, along with a squeegee to remove mud.

Dust billowed around them until a stray draft between narrow rills spirited it away.

"I give up," Mitch said, walking back to stare into Eileen's window. "What am I supposed to be looking for?"

"Let's say there's a river here."

"Hasn't been one for a few centuries, by the looks of things."

"Three thousand years, actually. Let's go back even further-say, more than ten thousand years."

"How much more?"

Eileen shrugged and made an "I'm not telling" face.

Mitch groaned, remembering all the troubles that came with ancient graves.

Eileen watched his reaction with a weary sadness that he could not riddle. "Where would you set up some sort of long-term fis.h.i.+ng camp, say, during the fall salmon run? A camp you could come back to, year after year?"

"On hard ground above the river, not too far."

"And what do you see around here?" Eileen asked.

Mitch scanned the territory again. "Mostly mudstone and weak terraces. Some lava."

"Ash fall?"

"Yeah. Looks solid. I wouldn't want to dig it out."

"Exactly," Eileen said. "Imagine an ash fall big enough to cover everything for hundreds of miles."

"Broken flats of ash. That would have to be above this bed, of course. The river would have worn through."

"Now, how would an archaeologist find something interesting in all that confusion?"

He frowned at her. "Something trapped by ash?"

Eileen nodded encouragement.

"Animals? People?"

"What do you think?" Eileen peered through the dusty winds.h.i.+eld of the Tahoe. She looked sadder and sadder, as if reliving an ancient tragedy.

"People, of course," Mitch said. "A camp. A fis.h.i.+ng camp. Covered by ash." He shook his head, then mockingly smacked his forehead, Such a dummy. Such a dummy.

"I'm practically giving it away," Eileen said.

Mitch turned east. He could see the dark gray-and-white layers of the old ash fall, buried under ten feet of sediments and now topped by a broken wall of pines. The ash layer looked at least four feet thick, mottled and striated. He imagined walking over to the cut and fingering the ash. Compacted by many seasons of rain, held in place by a cap of dirt and silt, it would be rock hard at first, but ultimately frangible, turning to powder if he hit it vigorously with a pick.

Big fall, a long time ago. Ten thousand and more years.

He looked north again, up a wash and away from the broad mud and gravel bed of the long-dead river, spotted with hardy brush and trees, a course now cut off even from snow melt and flash floods. Undisturbed by heavy erosion for a couple of thousand years.

"This used to be a pretty good oxbow, I'd say. Even in the Spent River heyday, there'd have been shallows where you could walk across and spear fish. You could have set up a weir in that hollow, under that boulder." He pointed to a big boulder mostly buried in old silt and ash.

Eileen smiled and nodded. "Keep going."

Mitch tapped his lips with his finger. He circled the Tahoe, waving his arms, making swoos.h.i.+ng sounds, kicking the dirt, sniffing the air.

Eileen laughed and slapped her knees. "I needed that," she said.

"Well, shucks," Mitch said humbly. "If I'm tapping into mystic spirits, I got to act the part." He fixed his gaze on a gap that led to higher ground, above the ash. His head leaned to one side and he shook out his bad arm, which was starting to ache. He got the look of a hound on the scent. Eyes sweeping the rough ground, he walked up the wash and climbed around the boulder.

Eileen yelled, "Wait up!"

"No way," Mitch called back. "I'm on it."

And he was.

He spotted the camp ten minutes later. Eileen came up beside him, breathless. On a level plateau only thinly forested, marked by patches of gray where the deep ash layer had been exposed by erosion, he saw twelve low-slung, light-weather tents covered with netting, dead branches, and bushes uprooted from around the site. A pair of old Land Rovers had been parked together and disguised as a large boulder.

Mitch had taken a seat on a rock, staring glumly at the tents and vehicles. "Why the camouflage?" he asked.

"Satellites or remoters doing searches for the BLM and Army Corps, protecting Indian rights under NAGPRA," Eileen said. Federal interpretation of the complaints of certain Indian groups, citing NAGPRA-the Native American Graves Protection Act-had been the nemesis of American archaeologists for almost twenty years.

"Oh," Mitch said. "Why take the chance? Do we need that now? Having the feds cover your dig with concrete?" That was how the Army Corps of Engineers had protected Mitch's dig against further intrusion, more than a lifetime ago, it seemed now. He waved his hand at the site and made a face. "Not very smart, staying hidden like this, hoping to avoid the Big Boys."

"Isn't that what you did?" Eileen asked.

Mitch snorted with little humor. "It's a fair cop," he admitted.

"These are not rational times," Eileen said. "You'll understand soon enough. Don't we all need to know what it means to be human? Now more than ever? How we got to where we are, and what's going to come later?"

"What are a few old Indian bones going to tell us that we don't already know?" Mitch asked, feeling his sense of discovery start to sputter and stall.

"Would I have called you out here if that was all we had at stake?" Eileen said. "You know me better than that, Mitch Rafelson. I hope you do."

Mitch wiped his hand on his pants leg and looked over his shoulder at the long fan of the wash. They had climbed about twenty feet, but he could still see evidence of ancient bank erosion. "Big river, way back when," he said.

"It was smaller at the time of our site," Eileen said. "Just a broad, shallow stream filled with salmon. Bears used to come down and fish. One of my students found an old male on the other side. Killed by an early phase of the ash fall, stage one of the eruption."

"How long ago?" Mitch asked.

"Twenty thousand years, we're estimating. Ash gives a good pota.s.sium-argon result. We're still refining with carbon dating."

"Something more than just a dead grizzly?"

Eileen nodded like a little girl confirming that there were, indeed, more dolls in her room. "The bear was female. She was missing her skull. It had been cut off, the bones hacked through with stone axes."

"Twenty thousand years ago?"

"Yeah. So my student crossed the Spent River and started looking at other reveals. Just killing time until the Land Rover came to pick her up. She found an eroded layer of high-silica ash, right down there, about fifty meters from where the camp is now." Eileen pointed. "She almost stepped on a human toe bone mixed with some gravel. Nothing spectacular, really. But she tracked down where it had weathered out, and she found more."

"Twenty thousand years," Mitch said, still incredulous.

"That isn't the half of it," Eileen said.

Mitch took a huge leap of supposition and bent backwards, then did a little dip of disbelief. "You are not suggesting . . ."

Eileen stared at him keenly.

"You found Neandertals Neandertals?"

Eileen shook her head, a strong no, then rewarded him with a teary-eyed smile that gave some hint of the distress she had gone through, at night, lying awake and thinking things over. then rewarded him with a teary-eyed smile that gave some hint of the distress she had gone through, at night, lying awake and thinking things over.

Mitch let out his breath. "What, then?"

"I don't want to be coy," she said primly, and took his hand. "But you're not nearly crazy enough. Come on, Mitch. Let's go meet the girls."

21.

BALTIMORE.

Morgenstern's questions were spot on and difficult to answer. Kaye had done her best, but she felt she had goofed a few of her responses rather badly. She felt like a mouse in a room full of cats. Jackson appeared more and more confident.

"The fertility group concludes that Kaye Rafelson is not the proper individual to continue research in ERV knock outs," Morgenstern concluded. "She has obvious bias. Her work is suspect."

A moment of silence. The accusation was not reb.u.t.ted; everyone was considering their options and the map of the political minefield around them.

"All right," Cross said, her face as serene as a baby's. "I still don't know where we stand. Should we continue to fund vaccines? Should we continue to look for ways to create organisms without any viral load?" n.o.body answered. "Lars?" Cross inquired.

Nilson shook his head. "I am perplexed by Dr. Morgenstern's statements. Dr. Rafelson's work looks impressive to me." He shrugged. "I know for a fact that human embryos implant in their mothers' wombs with the aid of old viral genes. Dr. Morgenstern is undoubtedly familiar with this, probably more than I."

"Very familiar," Morgenstern said confidently. "Utilization of endogenous viral syncytin genes in simian development is interesting, but I can quote dozens of papers proving there is no rhyme or reason to this random occurrence. There are even more remarkable coincidences in the long history of evolution."

"And the Temin model of viral contributions to the genome?"

"Brilliant, old, long since disproved."

Nilson pushed his scattered notes and papers into a stack, squared them, and thumped them lightly on the table top. "All my life," he said, "I have come to regard the basic principles of biology as tantamount to an act of faith. Credo, Credo, this I believe: that the chain of instruction arising from DNA to RNA to proteins never reverses. The Central Dogma. McClintock and Temin and Baltimore, among many others, proved the Central Dogma to be wrong, demonstrating that genes can produce products that insert copies of themselves, that retroviruses can write themselves to DNA as proviruses and stay there for many millions of years." this I believe: that the chain of instruction arising from DNA to RNA to proteins never reverses. The Central Dogma. McClintock and Temin and Baltimore, among many others, proved the Central Dogma to be wrong, demonstrating that genes can produce products that insert copies of themselves, that retroviruses can write themselves to DNA as proviruses and stay there for many millions of years."