This article first appeared in Issue 12 of our free digital magazine CURIOUS.
The rate of decomposition of the human body varies enormously depending on where it lies after its last breath. Kept in the cool conditions of a morgue, you can buy yourself time to plan a funeral and even embalm the body to keep it suitable for an open casket. By comparison, corpses left exposed to the elements can disintegrate rapidly, making it harder to identify the dead from sight alone.
It got us wondering if there’s a point beyond which little can be learned about a body, forensically speaking. However, as forensic anthropologist, taphonomist, and entomologist Dr Devin Finaughty of the University of Kent explained, even skeletonized remains can still tell a compelling story.
Does finding bodies that have been dead for a long time make them harder to study?
Devin Finaughty (DF): The more time that elapses after death, you lose context, and you lose evidence because the body is physically decaying. And the circumstances in which the body is in are changing. That introduces a lot of uncertainties. So, you're more constrained in terms of what you can figure out as you get further along in the post-mortem period. That doesn't preclude your ability to still generate a lot of information, but it really depends on what experts are involved.
For example, are you familiar with taphonomy as a discipline?
DF: It's inherently a study of preservation more than anything else. Now, obviously in forensic cases, our timescales are much shorter. We're still looking at preservation, but it's in the context of how quickly the body decomposes, and the role that different taphonomic agents play within that. That can include bacteria, plants, animals, or people.
So that's sort of like my bread and butter, but I'm also a trained forensic anthropologist, which specializes in looking at bones. And I do forensic entomology as well, which involves looking at the insects that are associated with death and decomposition.
From a forensic anthropological perspective, one of the main contributions they bring to forensic death investigations where skeletal remains are concerned is helping to reconstruct the person's identity.
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How does that work?
DF: It involves creating what we call the osteobiographical profile, and typically comprises an estimation of biological sex, age at death, stature, potential trauma that might have occurred either before or around the time of, or after, death.
There's also a lot of information you can pull up about a person's lifestyle from their skeleton. I like to say that our life stories are written into our bones; the types of activities that we do, the level of physical activity that we do, history of disease processes.
If you get really, really sick with something, that is often reflected in the bones. Ongoing disease processes – if they're quite systemic, or maybe sometimes very localized – can affect bone as well. Histories of surgeries, the insertion of prostheses, repairs.
We can reconstruct a person's diet at different stages of their lives depending on where we source the tissue from. Even when we’ve stopped growing, it doesn't mean that your bones just stop doing what they do. Your body continues to turn over that, and it's pulling in material from your diet as it does that. This means we can use stable isotope analysis to generate information based on your diet. Everything from the type of water you were drinking to the type of food that you were eating, all of that is written in bones.
Are some bones more revealing than others?
DF: Your teeth are particularly good in this regard. They recall what happened when your teeth were forming in early childhood, all the way up until your wisdom teeth form, which is going to be in your teenage years. That’s fixed, your teeth don’t continue to change. And then we can go right down to hair and fingernails, which will tell us what about the last few weeks and months before death.
All that is just around identity. There's also some really cool work that gets done by forensic facial artists who will look at the structure of your skull, and using an intimate knowledge of anatomy, combined with scientifically derived soft tissue depth standards, they can help to reconstruct what your face might have looked like. That method has a lot of potential, it's infrequently used as a conclusive means of identification, but it can generate new leads for investigation.
It means you can create a recognizable likeness of an individual, and send that out to the public. Then someone's like, “Oh, I remember that person,” and suddenly you've got a whole new set of potential leads for the case to help identify the body.
Dr Devin Finaughty will be back to discuss the trials and tribulations of forensic science in IFLScience’s first live virtual event, CURIOUS Live, taking place on October 21, 2023. Click to find out more and secure your spot.