Whispering bones: interpreting death as a forensic anthropologist

news.jpgBy Alicia Wikner

Executive Staff

With a lineup of bones on a table and three heads resting on chairs in front of it in Blackman Auditorium, Mary Davis opened her lecture on forensic anthropology entitled “The Ultimate Autobiography: What Your Bones Say After You’re Gone,” which discussed the specific clues human skeletons tell about the manner of their deaths as well as the way they lived.

Davis is a Research Associate with the Forensic Anthropology Center at the University of Tennessee-Knoxville (UTK), with Bachelor’s Degrees in Neuroscience and Anthropology as well as a Master’s Degree in Forensic Anthropology. At UTK she coordinates the Body Donation Program, which allows volunteers to donate their body to the Anthropology Research Facilities after their deaths, where students are trained in the field to understand the varying stages of decomposition of the human body.

She describes forensic anthropology as “an applied science which looks at all fields and involves application of science to facts related to criminal and civil legal action, including odontology, ballistics, chemistry and entomology.” These subsections are used to create a “Biological Profile” that the police force can then use to identify a victim, and in some cases when and how that victim died.

With the recent influx of shows that feature forensic anthropologists, Davis made very clear what the job was not about, exclaiming, “The FBI did not issue me a gun when I got my job!” She also pointed out the flaws of media representation when it came to forensic anthropology on shows such as the highly popular TV series Bones. Accuracy is often forgone for aesthetics. “The backlight on those tables makes for a lot of missing details,” she said.

So what does a forensic anthropologist do, and how do they do it?

“Search and recovery is the most important,” Davis explained. “We like digging in mud, dirt is cool.” Often they are called in for mass disasters, such as 9/11, or typhoons, when there is a large amount of dead bodies that need to be identified, severely decomposed victims, or when human remains are burnt, crushed, or fragmented. At times, they will also assist law enforcement in locating a body if they receive a tip.

Decomposing bodies can give a surprising amount of clues about the manner of death, since there are several factors that contribute to how fast or slow a body will decompose, such as temperature and humidity, insect/scavenger access, surface abandoning versus a burial, and exposure to weather, trauma, and clothing.

Bones, too, have a language of their own and help create the Biological Profile. The profile is split into five categories: sex, age, ancestry, stature, and pathology. The sex of a person can be determined by a skull, the long bone, or the pelvis. The pelvis is the most identifiable one, since it is constructed very differently from a biological male’s in order to allow childbirth.

Age can be determined by how fused your bones are; children have more than the typical 206 bones because human skeletons form in pieces that then fuse up until, on average, age 25. After this, the skeleton starts to deteriorate.

For example, in a young person, the Pubic Symphysis will have defined borders, while an individual over 50 years of age will have a border that is breaking down, with some pores beginning to show.

“I like to say I’m 25,” Davis said, laughing. “Once you hit 25, your skeleton is still breaking down, no matter how much you work out. If you take anything from this lecture it’s to drink your milk.”

Ancestry is often less an indication of race and more so an estimate of a person’s genetic heritage. The shape of eye orbit, how far midface protrudes from front of midface, and shape of the dental arcade can be used to determine ancestry, through Davis clarified, “Now there’s a lot more mixture of traits, so it’s important to know all of the variations to find an overarching theme. We define ancestry, not race.”

Statute involves finding a person’s height, whereas pathology focuses on identifying individuals by seeing if there are any diseases that have left significant marks on a person’s bones. For example, resorptive cancer eats at the bone. Other than these identifiers, forensic anthropologists examine wounds, such as bullet wounds, saw marks, and knife marks, which can be helpful in criminal investigations.

Davis summarizes the job’s most defining features as “determining biological profile, estimating  PMI (Estimating of Postmortem Interval), and interpreting trauma.”

“The average person has 26,079 days to build their skeletal autobiography,” she concluded. This fact prompts one to think: what will your bones say when you die?