Chapter Twenty-Eight
The DNA results presented Grand with an impossibility. They showed the presence of metabolic activity in the hair samples, most actively in the gene that regulates the chemical breakdown of glucose. That ruled out the hairs having been part of a Chumash paintbrush. But the test did not produce a match in the database of mammals indigenous to Southern California. It was possible and not unprecedented that an animal from outside the area had escaped from a zoo, circus, or private collection. Either no one had noticed it or was afraid to acknowledge it for fear of lawsuits or insurance claims.
It also meant that he would have to run a lengthy series of tests comparing the DNA of the hair to the DNA of all the mammals that were in the database.
Before Grand did that, though, he decided to have a look at the other test results. What he found there might help to narrow the search. As he loaded the data from the radiocarbon dating, Hannah asked Grand to explain how the dating process worked.
"Carbon 14 is a more massive form of carbon, one that's radioactive and loses electrons as it decays," he told her. "Since carbon 14 is created by interaction between solar radiation and earth's atmosphere, it becomes integrated in carbon dioxide and is found in all living things. When something dies and the carbon in the system is no longer replenished, the carbon 14 already present begins to decay. Because the rate of decay is constant, we're able to accurately determine when living tissue last absorbed carbon 14."
"Understood," Hannah said. "Then how do you determine the age of nonliving things like rocks and pottery and the Shroud of Turin?"
"All rocks, minerals, and other nonliving matter contain different kinds of radioactive material such as uranium, thorium, potassium-40," Grand said. "Those decay into different states which are also measurable."
"I see," Hannah said. She plucked several fries from the bag and ate them. "So we could test these fries using radiocarbon dating because they were once alive."
"That's right." Grand smiled at Hannah. "At least, you're assuming they were. You have to read the fine print at a place like Chris's Crinkles."
"What do you mean?" Hannah said.
"The last time I went to the movies with Rebecca they had something they called 'buttery topping' for the popcorn and a 'frozen dairy product' where they used to have custard-"
"Are you saying that these may be fake spuds?"
"It wouldn't surprise me."
Hannah shrugged and ate several more fries. "You could be right. But Chris Sheehy is a local businessperson and an advertiser, so I've got to patronize her place. Anyway, who knows? Maybe next week one of your scientific colleagues will find out that eating dead things with carbon 14 is bad for us. Potassium-40 may be all the rage."
Grand smiled as the results of the radiocarbon daring began to appear on the monitor. While he read the data his smile evaporated. "It can't be," he said.
"What?"
Grand finished the file, then scrolled back and began reading the figures again slowly.
"What can't be?" Hannah pressed.
"The radiocarbon dating results," Grand said. "They say these hair samples are nearly eleven thousand years old."
"You're joking," Hannah said. "But according to the DNA findings the hairs came from a living creature," Hannah said.
"They did," Grand replied.
"Is there any way something could have contaminated your samples, like microbes or germs?" Hannah asked. "Maybe they were mistaken for signs of life in the hair."
"That can't happen at the DNA level," Grand said. "The tests Tami ran take apart the hair itself. There's no way of mistaking that for a microbe."
"Well, something's obviously wrong," Hannah said. "And if the DNA tests are foolproof-"
"Then there must be a mistake in the age," Grand said. "I'm going to check the DNA analysis. The tests also give us a chemical breakdown. There may be something in the hair, a chemical, mineral, or radioactive element that could have skewed the radiocarbon result."
The fan in the computer hummed quietly as Grand asked the computer to identify elements and chemicals that were present in the hair. There was nothing unusual. Hydrogen, oxygen, carbon, magnesium, nitrogen, phosphorous, sulfur, and various salts.
Grand brought up the proportions of organic materials and other compounds. When those were on-screen he compared them with elements and compounds found in the hair of local bobcats, gray wolves, foxes, elks, field mice, and rabbits. He wasn't trying to determine that the hairs had come from one of those animals, only that the ratios were relatively similar.
They were, with two exceptions.
"The average water content of the other fur samples is 68.7 percent," the scientist said as he read the ratios. "The hair samples I brought in have an elevated saturation level of 87.6 percent."
"That sounds pretty high," Hannah said.
"Yes, but explainable. The hairs were probably submerged at some point down in that cavern. What I don't understand is this other figure."
"Which is?"
"Carbon dioxide," Grand said. "The random fur samples have levels that are an average of 300 percent higher than the hairs I found in the stalagmite. That shouldn't be. The air my creature breathed shouldn't have contained such low percentages unless-"
He stopped.
"Unless what?" Hannah asked.
"No. There's got to be a mistake," the scientist said as he went on-line to the UCSB Web site and accessed the Biological Sciences database.
"What are you doing?" Hannah asked.
"I'm asking the computer to give me the levels of atmospheric carbon dioxide eleven thousand years ago and today," he said as he typed. "If the older figures correspond to the CO2 levels found in the hair samples, it will corroborate the date the radiocarbon test gave us."
"In which case we have an eleven-thousand-year-old specimen with reliable DNA findings that tell us the specimen is alive," Hannah said.
"It's impossible, but that's pretty much what we'll have."
"I don't think I'll be running that information in tomorrow's paper," Hannah said. "I wonder if Gearhart's crime lab gave him the same results on the hair samples."
"That's a good question," Grand said. "If they did, that could be one reason he's being so tight-lipped. He doesn't want to look foolish either."
"After we've checked this out, maybe I should tell him what we've found," Hannah said. "See if that opens him up a little, maybe fills in a few missing pieces for him."
The scientist nodded and sat back.
As the computer worked on finding the data he tried to think of explanations that might reconcile the findings. The only thing he could come up with was that one or the other of the tests had somehow been compromised. If that were true, then the concentration of atmospheric carbon dioxide eleven thousand years ago could not be in the same proportion as the ratios the DNA test found in the hair samples. Otherwise, the tests would prove one another to be correct.
"How do we know what earth's atmospheric levels were eleven thousand years ago?" Hannah asked.
"From studying ancient ice," Grand said. "Scientists have taken thousands of deep core samples from ice in both the north and south polar regions. They've analyzed air trapped in bubbles in the ice and found a steady increase in carbon dioxide levels from prehistory to now."
"Increased why?"
"Mostly due to volcanic activity," Grand said. "Volcanoes pour massive amounts of carbon dioxide into the atmosphere. They also caused a greenhouse effect that was probably what ended the Ice Age and caused the spread of deserts and the destruction of countless ancient forests."
"So human burning of fossil fuels wasn't the initial cause of global warming?" Hannah said.