If you stumble across a pile of bones in the woods, can you tell if they are human bones, and if they are human, did they belong to a male or female? How old was he or she at the time of death? Was the individual tall or short? What killed him or her, and how long ago did the person die?
While we might be able to identify human bones, most of us cannot answer many questions about the bones, and most of the answers elude even law enforcement officers, coroners, and trained medical examiners. Forensic anthropologists are the experts who interpret skeletal remains.
In my latest novel, Karluk Bones, Jane Marcus and her friends stumble across skeletal remains near Karluk Lake on Kodiak Island. They find a skull as well as a long femur, so they know at least some of the bones are human. The remains don’t appear to be recent, but they also don’t look ancient, and Jane and her friends argue about how old they might be. Jane reports the bones to the Alaska State Troopers, but Sergeant Patterson also can’t guess at the age of the bones, so he hands them off to a medical examiner who in turn sends them to a forensic anthropologist, and she is able to answer some, but not all, of the questions about the bones.
I love learning, and one of the things I enjoy most about writing fiction or non-fiction is having the opportunity to dig into a new subject and study it not only until I understand it but until I know it well enough to explain it to my readers. Using science to help solve the mystery of the bones in my novel proved trickier than I expected, and Ying, my fictional anthropology student at the University of Alaska, ended up relying on cutting-edge scientific techniques to provide answers about the human remains Jane and her friends found.
Beginning with this post and continuing for the next two or three weeks, I will describe what a forensic anthropologist can deduce from bones.
Human or Non-Human
It is easy for us to recognize a human skull, and most laymen can identify many other human bones, but if you discover skeletal remains in the woods, human bones might be mixed with those of other animals. If a forensic anthropologist visits the scene, she can quickly separate human from non-human remains. If a forensic anthropologist is unavailable, then investigators must collect all the bone scraps and send them to an anthropologist to be sorted in the lab. Once they are in the lab, the anthropologist cleans the bones and attempts to provide a general physical description of the individual whose remains she is studying. The description includes:
- Gender
- Age at Death
- Race
- Height
The anthropologist also tries to try to determine the cause of death as well as estimate how long ago the individual died. This week, I will discuss how gender can be determined from bones.
Gender
The pelvis and the skull provide the most useful information for determining the gender of the individual.
Pelvis
Females have wider pelvises to provide enough space for the birth canal, and anthropologists use several definitive measurements to differentiate the pelvis of a female from the pelvis of a male. In most cases, though, a forensic anthropologist only needs to visually examine a pelvis to determine the gender of the individual. If the pelvis is available, it is the best bony structure to confirm the sex of the person.
Skull
Often, only the skull of an individual is found, but luckily, marked differences exist between the skull of a male and the skull of a female. An adult female’s skull remains slender and retains the smoothness of youth, while and adult male’s skull is more robust with heavier bones and larger muscle attachment areas. Females have a rounded forehead, while a male’s forehead slopes back at a gentle angle. A male has a more prominent brow ridge and square eye sockets, while a female has round eye sockets. Males have a square jawline, and a female’s jaw is pointed.
Since individuals vary, sex determination using only the skull is not as definitive as a confirmation made from examining the pelvis, but the skull usually provides the anthropologist with an educated guess at the gender of the individual.
Next week, I’ll discuss other characteristics a forensic anthropologist learns from reading bones. Meanwhile, be sure to sign up for my monthly Mystery Newsletter about true murder and mystery in Alaska.
Robin Barefield is the author of three Alaska wilderness mystery novels, Big Game, Murder Over Kodiak, and The Fisherman’s Daughter. To download a free copy of one of her novels, watch her webinar about how she became an author and why she writes Alaska wilderness mysteries. Also, sign up below to subscribe to her free, monthly newsletter on true murder and mystery in Alaska.
