Ageing skeletal material was trickier than sexing it (to begin with, you had a lot more than two possibilities), but in this case it was made easier by the presence of the two partially erupted third molars-the deservedly much-maligned wisdom teeth. Inasmuch as third molars, the most variable of the human teeth as to time of eruption, generally came in (when they came in at all) somewhere between the ages of eighteen and twenty-five, and these particular ones had not quite broken all the way through, it followed that the person had probably been somewhere between those ages when she died. (Forensic anthropology, he thought, not for the first time, involved an awful lot of “probablys.”)
The eating disorder? That had been easy, the work of a single glance. The edges of the incisors were thinned and “scalloped,” almost as if they’d been gently filed. And the lingual surfaces-the sides toward the tongue-were deeply eroded and discolored, almost through the enamel. On the two central incisors, it looked as if the dentin might be showing through in spots. When you saw incisors like these, especially on a young person, the most likely cause, and the first thing that came to mind, was bulimia: the habitual, repeated vomiting that went along with it brought up stomach acid that ate the enamel away.
Ergo, he was looking at the mandible of a large-boned female. In her early- to mid-twenties. With an eating disorder.
Claudia Albert. And the fact-well, the high probability-that it was Claudia Albert added weight to the idea that Magnus Torkelsson had been aboard, too, even if nothing of him were to turn up.
All these observations had been made without benefit of measuring instruments, regression equations, or statistical tables, but he had been at this long enough to feel reasonably comfortable about his conclusions without them. The numbers and tables came in handy when you were trying to convince a jury or a skeptical defense lawyer that you knew what you were talking about, but Gideon, like most of his colleagues, trusted more to his instincts-that is, his educated and well-honed instincts-than anything that came out of a computer. Anyway, in this case, there were no lawyers or juries to worry about.
Drowsy with the heat, his back against a post, his head drooping, he sat musing over the mandible for a while. If she had lived, those third molars would have given her a lot of trouble. They were both impacted-tipped toward the second molars in front of them-so that when they had fully erupted they would have been pressing hard against them, putting a strain on the fabric of the entire mouth. Most likely, they would have had to come out.
Wisdom teeth, he reflected; one of those little mistakes that the evolutionary process makes, or rather one of those little lapses. What most people never seemed to get clear about the way evolution worked was that Mother Nature didn’t give much thought to the big picture. She fussed and tinkered with the details that caught her interest, and let the rest take care of themselves. Once the hominid brain-case began to expand and the snout to retreat a million and a half or so years ago, the new, shorter face had less and less room for its mouthful of big, grinding, crushing teeth. They began to be squeezed uncomfortably together, not that that bothered Mother Nature. She just kept on squeezing, and the third molars, being the last to erupt, were always being faced with a shortage of space by the time they got there, so that they started coming up sideways or back-to-front, or any which way they could.
The way she usually took care of annoying little problems like that was to let us solve them for ourselves. That is, if impacted, diseased wisdom teeth and unhealthy, crowded mouths got to be enough of a problem, people would die from them earlier than the general population did, and as a result their representation in the gene pool would diminish, and eventually, given enough time, the trait would die out and be no more. In other words, Mother Nature left it to us to work the bugs out of her program. (“Sort of like we do for Bill Gates,” a student had aptly remarked the previous quarter.)
In the case of third molars, we were obviously still going through the process-they seemed to be becoming rarer with time-but modern dentistry, well-intentioned as it might be, had complicated things.. .
He became aware that the Cessna’s engines had been chattering for a while, and, looking up, he saw that the plane was slowly motoring over the lagoon toward them again. Had he been dozing? Apparently so; John had returned from the lagoon without his noticing and was just finishing his second sandwich and crumpling up the plastic wrap.
“Welcome back,” John said. “Have a good snooze?”
“I was thinking,” Gideon said. “Turning things over in my mind.”
“Yeah, right. I always snore when I turn things over in my mind, too. Listen, I got a question. This girl, this pilot, she had bulimia, right?”
“Right, bulimia nervosa.”
“Which is where you make yourself throw up after you eat.”
“Mm-hm.” He yawned, scratched his back against the post, and straightened up.
“But she was supposed to be this big, strapping kid. Aren’t bulimics underweight?”
“Interestingly enough, no. They’re never very much underweight, and usually above average weight, actually. You see, they don’t do it all the time. They go on periodic binges where they overeat, then make themselves vomit. You’re thinking of anorexics, who starve themselves or make themselves throw up or take laxatives or whatever, but they do it day in, day out.”
John cocked an eyebrow. “They’re never underweight?”
“No.”
“Never?”
“No.”
“It’s impossible to have a bulimic who’s skinny?”
“That’s right, because technically you can’t be a bulimic and an anorexic at the same time, so if a bulimic is morbidly underweight, she’s automatically classified as having anorexia, not bulimia.”
John, who had thought he was closing in for a rare Socratic kill, was clearly disappointed. “That’s… but that’s…”
“That is a salutary example of one of the tools of modern science,” Gideon said. “We experts use it all the time. It’s known as disposing of nonconforming data by means of semantic recategorization.”
“Science,” John said, shaking his head. “It’s wunnerful.”
“Hey, we’re done!” one of the brothers yelled from the plane as it neared the pier. “Got some good stuff for you.”
Gideon got up, stretched, swished some water around his dry mouth, and went with John to meet them. This time they tied up and Lyle quickly climbed down holding a small mesh basket. “Possible personal effects,” he said.
In the basket were the bent, lens-less frame of a pair of wire-rimmed glasses; a few coins-two quarters, a dime, a penny; a lidded coffee mug with a hula dancer on it; an enameled metal tourist souvenir, probably a trivet or a wall ornament, in the shape of the Big Island, complete with its two white-capped volcanic peaks in relief; a black plastic comb; and the rubber heel of a boot or shoe.
The Big Island souvenir was snarled in a crumpled tangle of gray duct tape, which Gideon picked at and managed to unstick.
“Amazing,” he said. “This stuff really does last forever.”
“That and Twinkies,” said John.
Some of the metal objects had a layer of green patina on them, but otherwise everything was in fairly good condition, and the ornament, the mug, and the glasses could well turn out to be helpful in identification. No bones, however, and Gideon had a hard time hiding his disappointment. “Well, this is good,” he said. “Somebody might remember some of this. See anything you recognize, John?”
John fingered the glasses. “These, maybe,” he said doubtfully. “I don’t know.”
“We can do better than that, prof,” Harvey said, jumping down onto the pier. “Lookee here, what we found jammed down under the right rudder pedal on the co-pilot’s side.” In his hand was a sodden, water-blackened cowboy boot, swollen and distorted, and missing its heel, but with the intricate stitching still in place. “You’ll love this.”
“A boot?”
“No, no, boot-shmoot, take a peek inside.” He tipped it so that Gideon could look into the top.
And there, nestled deep within, was the skeleton of a right foot, or at least all that could be seen of it: the talus and the calcaneus, the two uppermost bones of the human ankle and foot. There was little doubt that the rest of the foot was there, too. The bulky talus and calcaneus, their anatomical relations to each other only minimally disturbed, blocked the opening, and with the leather whole and the sole of the boot still attached, there was no place for the other bones to go.
“Hey, how about that?” he said, his enthusiasm reviving. The twenty-six bones of the foot and ankle were far from the most useful parts of the skeleton when it came to ageing, sexing, and so on (given his druthers he’d naturally have chosen a skull or pelvis or even a femur), but he had long ago found that there was always-always-something to be learned, whatever turned up. And a complete foot was not to be sneered at.
The boot, oozing water, was placed, sole down, on the massage table. With a pair of metal shears from the plane, Gideon sliced it open from the top down, first at the back, then down the front, and then-very carefully-over the instep, while John held it upright for him. When he had finished, he peeled the halves of leather apart, snipping a little more at the sole where it was necessary to get the halves completely spread. The few falling-apart shreds of sock still present were picked off and put aside.
“Wow,” breathed Lyle.
“Whoa,” said Harvey. “Fantastic.”
The skeletal foot, ossa pedis, lay upon the bed of clean, moist, white sand that covered the sole like an illustration in an anatomy text. Only a few of the phalanges-the toes-had been disarranged. The four men silently admired it for a few seconds, until Harvey abruptly sang out: “Lunch time, we got chicken fingers, we got barbecue chips, Twinkies, uh, we got Ding Dongs, uh, uh…”
“You got Ho Hos?” John asked hopefully.
“Of course, Ho Hos. Uh, Zingers, uh-”
“You guys go ahead,” Gideon said. “I want to look this over a little more. I still have a sandwich left. I could use a Coke or something, if there is one.”
The Shertz brothers, with chicken fingers on their minds and their interest in bones exhausted, retired to the Cessna for their meal.
“John, give me a hand with the table, will you?” Gideon said. By now the sun had started down and the massage table was no longer fully shielded by the thatched roof. “I don’t want the bones baking in that hot sun. They’ve been in the water too long; they’ll split if they dry too fast.”
“Thanks,” he said after they moved the heavy table a couple of feet. “Go get yourself something to eat if you want, John. I’m fine here.”
“Nah, I’m fine, too, Doc.”
Gideon stood looking down at the foot again. His sunglasses, smeared with perspiration and sunscreen, were laid on the table. He’d already made his first determination: The foot and the mandible were from two different people. You didn’t see feet like this in twenty-five-year-olds. The signs of arthritis in the joints, especially the metatarsals, the incipient osteoporosis, and the trivial and not-so-trivial deformities that sadly but predictably plague the ageing shoed (or booted) human foot suggested a minimum age in the fifties and probably older. The grainy look and feel of the bone went along with this; nothing like the young, baby-bottom smoothness of the mandible. As to sex…
“Well, you know,” John said brightly, “maybe I’ll just go see what the situation is with those Ho Hos, after all.”
“Hm? Okay, sure,” Gideon mumbled abstractedly.
“I’ll bring you that Coke when I come back.”
“Uhm.”
As to sex, he wouldn’t want to make a guess at this point; not with just a foot to go on. The bones were neither too big and robust to be female, nor too gracile to be male. There was a method, not a hundred percent reliable but better than guessing, for determining sex from combined measurements of the talus and calcaneus, but it took discriminant function analysis to do it, a statistical technique requiring a table of coefficients carried out to the fifth decimal place. And that he didn’t have. Besides which, the only measuring instruments the Shertzes had come up with were a metal tape measure and a yardstick, neither of which could come close to handling the tricky measurements involved on these asymmetrical, uniquely shaped bones.
There was also a way to estimate height from the length of the metatarsals, the long bones of the foot, but that, too, would have to wait, and for the same reasons.
For the moment, he was absorbed in looking closely at the calcaneus, which he now held in his left hand, turning it this way and that to examine the rough, curving, asymmetrical surfaces. Yes, this was a row of tiny exostoses-little spicules of bone-just forward of the calcaneal tuberosity, on the underside. And another little ridge that didn’t belong there, running longitudinally just in front of it, and a third bumpy, inch-long crest of bone on the upper side, where the bone was narrowest, behind the posterior articular surface. These irregularities were calluses, the strong, bony reinforcements the body laid down to heal fractures and strengthen repairs.
So this heel bone had been broken at least three times, maybe more (bone calluses could disappear completely, given long enough). All appeared to have been “stress” or “fatigue” fractures: not the result of sudden compression or blunt-force trauma, but of the building-up of repeated, relatively low-grade stress over time. Gideon examined the rest of the bones, looking for similar injuries. Nothing. So here was a man that had fractured his heel bone three times, but had never, as far as he could tell, broken any of the other bones in his foot.
Now that was interesting. The usual fatigue- or stress-related foot injuries-from walking, running, jogging-were found in the metatarsals and the toes; not in the calcaneus. Heel spurs, yes; you got those in spades, but not fractures, not usually. When you did see stress fractures of the calcaneus, however, they tended to be found in people who jumped or otherwise dropped from heights, with recreational parachutists and hang-gliding enthusiasts topping the list of orthopedic surgeons’ favorites. In those cases, however, associated injuries of the other bones of the foot could be expected; you didn’t just break your heel bone, you snapped a couple of metatarsals or crunched a cuneiform as well.