John, whose interest in forensic anthropology did not extend to sitting around watching Gideon stare at a bone and mumble to himself, stretched, stood up, and announced that he was going off to take another swim.
“Okay, right,” said Gideon, absorbed in the examination.
However he’d arrived at it, John was correct about the mandible being Claudia Albert’s. According to the Torkelssons, she had been a big, sturdily built woman (a lummox, Dagmar had called her) of twenty-five, troubled with bulimia. And the jawbone perched on his knee had almost certainly belonged to a big, sturdily built woman of twenty-five or so, afflicted with an eating disorder, most likely bulimia. Given the context and the circumstances, there wasn’t much room for doubt as to who she was.
Despite some of the ambiguous criteria, determining the sex had been the easy part. (Determining the sex was
But the ruggedness and size were useful in their own right, in that they were what had told him that the mandible’s owner had probably been large and strongly built. When a mandible, or any other bone, was robust and heavily ridged and roughened by muscle attachments, it meant that the muscles that had been attached to it were strong and well-developed. And if the mandibular muscles were well-developed, it was reasonable to assume that the cranial and neck muscles were well-developed, and if that was the case, then it was only reasonable to suppose that the trunk and limb muscles were well-developed, etc., etc. The good old Law of Morphological Consistency.
So it was possible, even from a single bone—the mandible—to make some assessment of overall size and physical condition. Of course, the Law of Morphological Consistency wasn’t exactly a law, it sometimes happened that a person might have a strongly developed jaw and neck coupled with a weak thorax, or thick arms coupled with spindly legs, and when such things occurred, anthropological assessments went awry. But they didn’t happen very often, and unless something turned up to contradict it, Gideon would stick with his reading. He’d rather have had a few more bones to look at, but in this kind of work, fragmentary remains were the rule.
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.”
