Forensic Anthropology: When The Bones Speak And Why It Is Important

First of all, what is Forensic Anthropology? To be clear, there is a big anthropological universe but most authors rely on the fact that its division starts with the big four: Archaeology,  Linguistics, Cultural Anthropology, and Physical Anthropology.

Physical Anthropology studies the human on a biological dimension and inside of its many branches, comes Forensic Anthropology whose goal is identification. This identification is made in a legal context, to solve cases and also to give relatives a closure.

There are multiple factors that derived from what now is Forensic Anthropology, the main importance of it is on how helpful it can be in the legal context; Forensic Medical Doctors are the ones oriented autopsies that are made in a scenario with identifiable bodies. Whenever there is still fingerprints, recognizable face or body features susceptible of identification, there is no need for a forensic anthropologist.

But when a lot of years have passed since the person died, or the circumstances of death leave the unidentifiable remains; being it burnt bodies, human remains who were intentionally reduced or modified, and missing people inhumated in illicit contexts (forced disappearance), there is when forensic anthropology is fundamental.

In some cases like the South American dictatorships, the remains of the detained-disappeared are traced by their own families, sometimes in the context of organizations. In cases of recent disappearances usually, the communities and law enforcement participate in the trace or recovery of remains.

Image 1: March of relatives of detained disappeared during dictatorship (1986) by Kena Lorenzini

It is important to read the bones and even more, it is to understand them properly. There is the “basic four” at the moment of the analysis of human remains; this is the first step that takes place when remains are already in the laboratory:

APPROXIMATED AGE (at death)

The moment when reality hits hard and tv shows are not helping; the human remains belong to a “sub-adult”, being a human that hasn’t reach its full development, it is possible to get a very accurate age. But from 16/18 years and the following years, we talk about an age range; there are three categories “young adult”, “middle adult” and “older adult”. There is no way to look at the long bones, skull, and teeth and say: “he/she was 35 and 4 months” even if tv shows made it look like this. There can be reliable reports talking about 41-50 years, for example.

SEX

It can be easily done in “grown-up” remains, even there are researchers developing formulas to try to have a percentage of possibilities of being “female” or “male” in sub-adults. It is way more accurate checking on adult bones; it can (except in some cases with lack of material or very special skeleton features) be very easy to determine using the classic methodologies, especially the hip bones.

Image 2: General example of Sexual Dimorphism in Skull.

ANCESTRY

Here is delicate: It is possible to study the remains, especially the skull, to check some features that may indicate some tendency (scored in percentages) in this regard.  Everything in the seeks of identification, ancestry estimation can be especially useful if the observed features are not average on a very homogeneous population. Let´s remember that the main goal is identification. It shall not be used to establish hierarchies in regard to ethnic features in the bones because is not related to functions of any kind.

STATURE

Traditionally it has been done with the Femur or Tibia, nowadays different experts have developed formulas to estimate stature using other bones, even long bones of the arm. All of the formula development is really helpful because not always there is the disposition of the full skeleton. In the best cases,  formulas to estimate height developed locally, exist or can be developed with the updated average height of the population by sex. The more population-oriented and updated the formula, the more accurate the outcomes are. Let’s also say that all of them contains a margin of error (between 1 and 3 centimeters)

Image 3: Bones of the leg in relation to the human skeleton.

Misconceptions about how it works

Knowing that we might doubt when a tv show says things like “that femur lesion, probably is a soccer player”, and no. Totally not going to happen in real life; one sign on the bone’s surface can have multiple-option origins: From the expression of a metabolic condition to an incredible number of activities. Another factor to have in mind is that only in ideal cases all the bones of an individual are recovered, sometimes the available fragments are not enough to figure one or more of the basic information. Even by having all the remains of an individual, it can only determine a potential cause of death, with no absolutes.

After the basic four are determined, the following steps are the analysis of lesions; pathologies, taphonomic processes, analysis of associated material (ideally by a forensic archaeologist), comes the extraction of DNA samples. The samples that are taken for DNA tests are from the hip bones, if possible (2 grams at least) followed by a comparison with a pre-existent database of missing people, identification finally happens.

The main obstacles 

In the real world not always there is an updated database for long-term missing persons with the necessary information to match samples. DNA  analysis can be very expensive if it needs to be certified, which has been recommended especially for cases of human rights violations. In many places,  if there is a Forensic Anthropology unit or laboratory, there is not always a forensic anthropologist there. 

The saddest cases happen when the last relative or close person of the disappeared dies without knowing what happened to their beloved one. Many regions in the world have zero public policies in regard to these matters because memory and justice are not common or comfortable words for administrations.

Be nice with your local forensic anthropologists and whoever you know is waiting to know what happened to their beloved ones, being it 50 years ago or last month.

Sources

Image 1: Kena Lorenzini (1986) March of relatives of detained -disappeared. Ahumada street ate the corner with Compañía de Jesús. Digital collection “Fotografí­as de Kena Lorenzini, 1984-1992: Bajo el lente de lo político”, from Museo Histórico Nacional de Chile.

Image 2:  Krenzer, U. & Centro de Análisis Forense y Ciencias Aplicadas. (2005). Compendio de métodos antropológico forenses para la reconstrucción del perfil osteo-biológico. CAFCA. Guatemala.

Image 3: Crossfit. (2019, July 19). Bones of the knee. https://www.crossfit.com/essentials/the-knee

Lundy, J. K. (1998). Forensic Anthropology: What Bones Can Tell Us. Laboratory Medicine, 29(7), 423-427. https://doi.org/10.1093/labmed/29.7.423

Ubelaker, D. H. (2018). A history of forensic anthropology. American Journal of Physical Anthropology, 165(4), 915-923. https://doi.org/10.1002/ajpa.23306

Wiersema, J. M. (2016). Evolution of Forensic Anthropological Methods of Identification. Academic Forensic Pathology, 6(3), 361-369. https://doi.org/10.23907/2016.038