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Forensic anthropologist Bruce Wheatley (Photograph by Randal Crow) |
By careful study of the bones, Wheatley can determine—with astonishing accuracy—the age, sex, race, and stature of the deceased, as well as many other facts about the person’s lifestyle and culture.
“Basically, I’m handed a bag of bones and asked to tell somebody what’s in it,” Wheatley says. Right away that puts him at a bit of a disadvantage.
“I could be a lot more help if I were present at the excavation site,” he explains, “because the site itself can help me tell right off whether the bones are human, and whether there are certain pieces—teeth, for example—that should be collected to determine factors such as race. As a forensic scientist, I’d like to get more anthropologists with backgrounds such as mine involved earlier in the process of identifying skeletal remains.”
Making a Picture
Forensic anthropology, Wheatley says, is one of the best-known applications of physical anthropology. A good forensic anthropologist has to be skilled in a lot of things—including archaeological field techniques, functional anatomy, human paleontology (fossils), and paleopathology (ancient diseases). All of the above can come into play when Wheatley begins to “make a picture of who someone was.”The first step is what forensic anthropologists call “doing the big four”—identifying age, sex, race, and stature.
Age, says Wheatley, is determined in a young person by the length of the bones, the extent of fusion of the epiphysis (the caps on the ends of long bones that fuse completely with the bones after the age of 20), and the status of the teeth, which anthropologists refer to as dental eruptions.
“If the skeleton is over the age of 20, we use other techniques,” Wheatley says. The epiphysis on the sternal end of the clavicle, for example, fuses around the age of 30. The sternal ends of the fourth rib change as people get older. “If you look at the depth of the pitting on that rib, you can pinpoint age fairly accurately—plus or minus two years,” he says.
After the age of 30, Wheatley says, “you go by the signs of deterioration. You start seeing lower back problems, bones becoming less dense and more porous, increases in little arthritic projections, work-related injuries, and so on.”
Gender can be readily identified by examining the pubis bone, which is elongated in women to allow for childbirth—although the skull, too, is a good indicator, Wheatley points out. “It’s true that men have big heads,” he laughs. “Females are usually smaller and more delicate. You can get an 85- or 90-percent probability on sex from the skull.” In fact, Wheatley usually begins his examination with the skull, because so much can be determined from it.
Race is a much more complex issue. And it’s getting more complex all the time, Wheatley says. “Just walking around the UAB campus, I see so many signs of increased racial mixing,” he says. “For example, every day on the street I see white students with high cheekbones”—a sure sign, he says, that the races are becoming less and less distinct as the planet’s population moves toward a multiracial citizenry.
For that reason, racial identification these days is kept to the basics—white, black, Asian, or Native American, based on distinctive characteristics of the skeleton, regardless of what the person’s skin may have looked like.
Determining stature is a matter of applying a mathematical equation called a “regression equation” to the measurement of the femur, or thigh bone, which is the longest bone in the body. This data is combined with a similar measurement of the tibia, or lower shinbone, to provide a very accurate estimation of height.
Data on the Dead
Once Wheatley has finished his examination of a skeleton, he transmits his data to a national forensic skeletal data bank. The data bank serves as a resource for scientists such as Wheatley in two important ways. First, it provides an overview of the American population, which is changing all the time. The data demonstrate the changing racial profile of America, for example, as well as the fact that people just keep getting bigger. The other important function of the data bank is that it allows scientists to compare the results of their examinations with data in the bank and thus determine the probabilities of accuracy of their results.But how do scientists tell if a set of remains are those of a specific person? “It’s largely a process of elimination,” Wheatley says.
When he begins an examination, Wheatley prefers not to know anything about the case. “It can bias you,” he explains, “and it’s best to look at the remains objectively. I usually don’t know much in advance anyway; I submit my report and then hear the story at the end.”
Typically, he looks at the skull first, to determine age and then sex. In some cases, he compares the skeletal DNA to DNA from the mother. Sometimes injuries can be matched to X rays or diseases traced to scars on certain bones. Lines on the teeth, for example, can indicate that the person took antibiotics at a particular time.
If a skeleton is an ancient one, much information can be gleaned from careful study of the bones. The bones of the upper body, for example, are affected in specific ways by the growth of musculature, indicating upper-body strength. Particular kinds of injury to the fingers suggest heavy or difficult manual labor, and certain anomalies in teeth indicate that rough material such as ground stone was mixed with food eaten by the deceased. Cultural artifacts found in context with the skeleton are the most useful indicators of the bones’ overall age. “If you find a pop-top,” Wheatley says, “you know the person died after 1962.”
Pieces of a Puzzle
In the nearly 20 years since Wheatley moved to Alabama from the San Francisco area, he says he has “seen it all” during the course of his forensic work. “There are all kinds of people out there doing all kinds of things,” he says simply.Although Wheatley doesn’t like to dwell on the oftentimes gruesome nature of his work, he has, he says, been asked to participate in investigations of satanic rituals and has examined skulls covered with wax drippings and burnished to a smooth, mellow patina—a sign of repeated handling. He has also examined bones brought home as trophies of war by veterans of active military duty.
Some of Wheatley’s sadder assignments have required him to help identify particular people who are missing and believed dead. A few years ago, for example, he examined the bones of a young boy lost on a camping trip. “Another time,” he says, “there was an explosion at a manufacturing plant on the west side of town. One man never turned up afterward. The police finally brought me one piece of bone and asked me to tell them whether it belonged to the man. All I could determine was that it was a male human shoulder bone. Eventually, authorities decided it must have been the man, because he never turned up.”
Interestingly, Wheatley says Alabama is at the forefront of forensic anthropological testing and is a leader in establishing a statewide DNA bank. UAB was one of the first universities in the country to establish a forensic DNA program.
But why would anyone be drawn to the study of bones—especially given the sometimes bizarre nature of the work? Wheatley ponders the question and finally says in his characteristically matter-of-fact style: “I guess I’ve always just loved a good puzzle.”
This article originally appeared in the Fall 1998 issue of UAB Magazine.