The phenomenon of disappearances challenges and questions the capacities and resources of the Mexican State to respond to a situation that has become a scourge for Mexican society.

The discovery of clandestine graves located in national territory that, in accordance with the official figures corresponding to the period from January 1, 2007 to September 30, 2016, made known to the Comisión Nacional de Derechos Humanos (CNDH) by local law enforcement agencies, amount to 855 clandestine graves, from the interior of which, 1,548 bodies and 35,958 bone and/or human remains were exhumed.

Many of these graves were located by members of the civil society, who worked tirelessly to find their loved ones and that too in the absence of adequate and timely response from the public security and law enforcement authorities.

They were forced to become investigators who without any economic resources or scientific knowledge have to go to the fields, mountains, hills, wastelands, among other places of the national territory, to carry out excavations with rudimentary tools.

By doing so they have found a considerable number of illegal burials, which, prior to the respective genetic opinions, has led to locate victims of disappearance.

A total of 102 proposals were formulated for comprehensive attention to the problem of the persons disappearance on the country.

The proposals deal with the following subjects:

- Comprehensive legislation on the disappearance of persons

- Registration of missing persons

- Search, location and investigation of missing persons

- Location and registration of clandestine graves

- access to justice; protection measures

- reparation of damages and attention to victims and family members

- Prevention of crime and human rights violations

- Human identification; acceptance of the competence of the United Nation Organization (UNO) Committee on Enforced Disappearances

- Compliance with the 64 recommendations and proposals made by UNO bodies and the Organization of American States

- Requests for information from other human rights protection institutions

- Follow-up on the proposals contained in the special report

The Human Identification of Disarticulated Corpses in Clandestine Graves

Post-mortem mutilation of a corpse is a criminal form of separation of body parts for various reasons.

The proper approach, from the place of discovery to the examination in the morgue, is essential for the collection of evidence that allows the reconstruction of the investigated event.

In the clandestine graves found in Mexico, it is not clear if these bodies were dismembered while alive as a form of torture, or if they were dismembered to facilitate their transfer and burial.

In recent years, Mexico has experienced a forensic crisis; local media have reported an increase in the number of cases of criminally mutilated bodies.

When fragmented bodies or anatomical parts are found at the scene, it is up to forensic physicians to differentiate whether they are human or animal remains; they must also establish whether the fragments are the result of non-criminal forms of ante-mortem amputation such as pieces of surgical pathology, accidental sections or loss of body segments.

It is also possible that the parts are the result of criminal mutilation of living persons as a form of intimidation or message, or that the amputations are the result of ante- or post-mortem animal activity. 

Post-mortem criminal mutilation is the intentional fragmentation of a corpse carried out for various reasons (transporting the body from the primary scene, preventing identification of the deceased, or sending a message).

Once the body fragments are found, the analysis of the site, the circumstances of the finding and the subsequent examination of the anatomical elements facilitate the determination of the type of mutilation and provide fundamental elements for the police and judicial investigation.

The desecration of corpses, which includes mutilation: dismemberment, dismemberment and decapitation, has been practiced since the origins of humanity for different reasons and motivations: as war trophies, acts of revenge against the enemy, part of symbolic or religious rituals and capital punishment.

The Phytoliths: The Soil Memory in Dental Tartar

After finding the clandestine graves and classifying the dismembered structures and organs, most of the time, human identification is complex for the grieving families.

Genetic comparison is a methodology that becomes complex because many bodies found in the north of the country belong to the center or south of the country and vice versa.

This makes it complex, costly and difficult to locate relatives, a solution is the analysis of dental tartar. In our teeth there are remains of the food we consumed in our place of origin.

Phytoliths are another secret hidden in soils.

To some extent, like seed banks and pollen analysis, they inform us about the vegetation that existed in the past, at a certain time and place.

Phytoliths are a product of plant metabolism related to the set of processes we call biomineralization.

What matters to us here is that they are minerals (others of biogenic nature are described below) elaborated by plants, accumulating in the soil for millennia.

Their study allows us to learn about the past of vegetation and, as a corollary, bioclimates, paleoenvironments, archaeology and ethnoagriculture.

The study and analysis of this type of biominerals is not new, although its use has not been extended among the scientific community until the 90's of the 20th century [4].

Well, this invisible subuniverse, as we will see below, turns out to be a record or archive of the past hidden in the soils, whose usefulness is very relevant in many types of research.

The silica opals released by the vegetation, which, in the long run, will be part of its fingerprints in the edaphic environment.

Phytolithic Research: Its Perspectives in Forensic Science in Mexico

To begin with the definition: A phytolith, according to the definition given by F. Ehrenberg (1854) for biolith, is any mineralized body integral of organic tissues that are produced by ergastic substances (resulting from metabolism); in particular, phytoliths are bioliths of vegetal origin, of microscopic size and chemical nature preferably siliceous or calcic.

Since the first scientific papers in the 1800s, the history of phytolith studies has been related to other disciplines.

Although Ehrenberg (1843) initiated these studies by analyzing different types of sediments, it was botanists who were concerned with describing phytoliths in their anatomical studies.

Later, soil scientists (soil specialists) discovered the importance of the presence of phytoliths and used them as a tool to establish the evolution of soil profiles.

In this line of research, phytoliths were used to study the deposits of lagoons, lakes and rivers.

Recently, Phytolithology has had its great impulse due to its application in archaeological or ethnobotanical studies, to the point of being considered a discipline in itself.

Paleobotany allows us to know their characteristics and apply them to the knowledge of paleocommunities (the conditions of the environment in which they developed; the conditioning factors presented by the climate, the soil, and the rest of the ecosystem where they lived).

Phytoliths are a valuable tool in this sense, and, together with the analysis of pollen remains (pollen), constitute the main avenues of knowledge that paleobotanists have [6], some phytoliths depicted in Figure 1.

Currently in Mexico, the analysis of phytoliths in dental tartar is used to elucidate where the dismembered body was from, bringing it closer to the forensic services of the region to make it easier to locate its relatives.

Figure 1 - Phytoliths 

The prompt location of the next of kin guarantees the post mortem rights that are guaranteed by the grieving families, considering that respect for their honor, respect for their wishes regarding the final destination of their property, including the body or its organs, a dignified burial in accordance with their beliefs, identification of the remains and repatriation if necessary, among others, should be considered together under the denomination of "post mortem rights"; as well as the recognition of their legal personality (death certificate).

Conclusion

Phytolith analysis provides a general overview of the consumption of vegetables regardless of the process to which they have been subjected.

Chopping, grinding, boiling, roasting, etc., does not alter the protocols to be followed or the results, since the phytoliths are not modified when the vegetables undergo these transformations.

The information provided by archaeobotany and zooarchaeology can be combined with each other and with the biogeographical knowledge of the region being studied, and thus obtain a more generalized idea of the use of plants or animals for different purposes.

It also allows in some cases to determine if the presence of some remains is due to the fact that they were transported to that place by man through dental tartar.

Silica opals, known as phytoliths, are microscopic botanical structures that can be preserved for thousands of years in the soil.

For this reason, they provide insight into the interrelationships that existed between plants, ecosystems and ancient and present-day human communities.

References

1. Efraín Tzuc, (October 8, 2021), A dónde van los desaparecidos: México rebasa las 4 mil fosas clandestinas, 40% se encontraron en este sexenio, https://adondevanlosdesaparecidos.org/2021/10/08/mexico-rebasa-las-4-mil-fosas-clandestinas-40-se-encontraron-en-este-sexenio/

2. CDNH México, (December 21, 2022), Informe especial sobre desaparición de personas y fosas clandestinas en México, http://informe.cndh.org.mx/menu.aspx?id=30100

3. Rosales, G. (December 21, 2022) Hallazgos necrópticos observados en piel y hueso que dejan los instrumentos utilizados en el desmembramiento criminal en cadáveres ingresados al servicio médico forense del distrito federal en el periodo de enero de 2008 a enero de 2010. http://www.repositoriodigital.ipn.mx/handle/123456789/12229.  

4. Hou-Yuan Lu, et al, “Phytoliths as quantitative indicators for the reconstruction of past environmental conditions in China I: phytolith-based transfer functions”, Quaternary Science Reviews 25, p.p. 945–959, (2006).

5. Jennifer Watling, José Iriarte, “Phytoliths from the coastal savannas of French Guiana”, Quaternary International 287 p.p. 162-180, (2013).

6. Dolores R. Piperno, “Phytoliths: A Comprehensive Guide for Archaeologists and Paleoecologists”, Altamira Press (2006).