Introduction:
Taphonomy, as defined by the Russian paleontologist A. Efremov in 1940, is “the study of the transition of organic remains from the biosphere into the lithosphere”. The taphonomic process begins with the necrological phase which deals with the death of an individual. This is followed by a pre-burial biostratinomical process where the body gets destroyed by weathering and disarticulation, biotic extrinsic factors (Microbes and Arthropods), avian and mammalian scavengers and gnawing by different animals. Post-burial, the bodily remains go through a diagenetic process, where the organic materials gradually interact with the underground environment ultimately leading either towards lithification or complete dissolution [1–3]
There has been a recent trend to establish Human Decomposition Facilities all over the world in order to better understand Human taphonomy process in a variety of climatic conditions. Forensic Anthropology Center at the University of Tennessee, Knoxville, TN, USA was the first such endeavor in 1981 to study the decomposition process on human cadavers. Since then, eight facilities in the USA, one in Australia and one in the Netherlands were established, with the Forensic Anthropology Research Facility (FARF) at the Texas State University, San Marcos, TX, USA being the largest one. Out of total ten facilities created so far, six of them are associated with the departments of Anthropology in the respective universities [4].
The need for Human Decomposition Facilities
So far, due to a lack of dedicated human decomposition facility, animal analogues especially rabbits [5], Mole-rats [6], and pigs [7] have been used for decomposition research in India. Decomposition rates for animal carcasses are different than human cadavers where the inter-individual variation is much higher in the latter which is attributable to the variations of intrinsic factors of the body (i.e, body mass, gut microbiome, health, drugs etc.)[3]. Even the spatial scavenging patterns of animal carcasses and human cadavers by various taphonomic agents differ significantly [4,8]. Since the conclusions drawn on animal carcasses cannot be directly applied to human bodies, the previous studies have highlighted the unsuitability of animal analogues for human decomposition research [4]
Loss of biological information during human body decomposition is not random and rather a systematic process which is mostly dependent on environmental and climatic conditions (i.e, temperature, water, oxygen, acidity, wrappings, surface/buried/aquatic deposition, burial depth etc). During decomposition, a human cadaver goes through five stages viz., “fresh, early decomposition, advanced decomposition, skeletonization, and extreme decomposition” where destruction of the skeletal remains is achieved at the final stage [3]. There are several methods to quantify the gross morphological changes in the decomposing human body for the estimation of post-mortem interval (PMI) that is used to estimate the time since an individual had died. Most notable of them are the Total Body Score (TBS), Degree of Decomposition Index (DDI), Accumulated Decomposition Score (ADS), Total Aquatic Decomposition (TAD) and Accumulated Degree Days (ADD) which has been extensively used as predictor variables for PMI estimation equations [3]. However, these scoring systems are highly variable and dependent on the immediate environment which makes the PMI estimation process highly sensitive to geographic and climatic fluctuations. Therefore, region specific and season specific PMI estimation equations needs to be formulated for India which will aid in medico legal investigation making it more accurate [4].
Discussion and Conclusion
India is home to a wide variety of climatic regions and each region has further seasonal variations. Detailed investigations regarding how Indian climatic variation affects the rates of human decomposition are required. Microbial succession and faunal succession by arthropod species on decomposing human body might possibly be India specific and requires further observations. Scavenging patterns of avian and mammalian taphonomic agents in India may also be different than their north American and European counterparts due to the ecological differences. In addition to this, further investigations are required from biocultural perspectives to find out if decomposition rates are affected by diseases prevalent in India (such as diabetes) and Indian lifestyle variations including dietary habits. This calls for dedicated Human decomposition research facilities associated with the department of anthropology in various Indian universities in each climatic region of the country to formulate specific standards regarding PMI estimation.
Such facilities could utilize the body donation programmes in Indian medical colleges under the same ethical constraints with informed consent, especially for the cases where a donated body gets rejected for anatomy dissections due to deformities, amputations or lesions. In addition to this, the autopsied bodies could also be utilized for decomposition research as a beneficial alternative to burial or cremation with consent from the immediate relatives of the donor. Such forensic anthropological research infrastructure would demand secure outdoor facilities with trained personnel who has experience in handling corpses with respect and dignity of the body. A dedicated mortuary and an attached classroom will also be required for training the students as well as forensic practitioners. Biological and Forensic anthropology students in India do not always have access to courses involving cadavers, and institutional support is necessary for introduction of such courses which will enable the students to get rid of any anxiety dealing with dead bodies and also getting acquainted with sights and smells of decomposing human remains. Students can also get trained on remote sensing techniques for the exploration of decomposing human remains and excavation techniques for the recovery of buried remains. However, students will also need to get trained on blood-borne and air-borne pathogens, and risks of contamination while handling cadavers with significant viral infection.
Apart from PMI investigations, some other forms of research that could be undertaken once such facilities are established in India include search and detection of clandestine remains, joint disarticulation and bone displacement of a human body in both archaeological and forensic context, training of human remains detection dogs, human identification from commingled remains, putrefactive transformation of finger and palmar dermatoglyphic traits, transformation of facial tissue thickness during post-mortem interval (for forensic facial reconstruction research), decomposition of frozen remains, forensic entomological studies, investigations of trace evidences, vegetation and fungi composition found in India in close proximity to the cadaver laying on surface, and root etching. Once the decomposition study has been concluded, the remaining skeletal remains can then be archived in a skeletal repository for future craniometric and osteometric research which at present mostly rely on archaeological collections. Thus, establishment of such facilities will have manyfold applications including an immense pedagogical value for forensic anthropological education in India and will also expand the horizon of future research to bridge the gaps in current forensic literature.
References
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- Grupe G. Taphonomy and fossilization. The International Encyclopedia of Biological Anthropology 2018;1-8.
- Wescott DJ. Recent advances in forensic anthropology: decomposition research. Forensic Sciences Research 2018;3:327-342.
- Williams A, Rogers CJ, Cassella JP. Why does the UK need a Human Taphonomy Facility? Forensic Science International 2019;296:74-79.
- Bharti M, Singh D. Insect faunal succession on decaying rabbit carcasses in Punjab, India. Journal of Forensic Sciences 2003;48:1133-43.
- Hore G, Parui P, Saha GK, et al. Variations in colonization and succession pattern of dipteran flies of forensic importance on Indian mole-rat carcasses in variations in colonization and succession pattern of dipteran flies of forensic importance on Indian mole-rat carcasses in urban and. Malaysian Journal of Medical Research 2017;1:52-62.
- Kaur P, Bala M. Insect faunal succession studies on pork carrion in Punjab, India. Journal of Entomological Research 2018;42:287-294.
- Young A. The Effects of Terrestrial Mammalian Scavenging and Avian Scavenging on the Body. In: Taphonomy of Human Remains: Forensic Analysis of the Dead and the Depositional Environment. Chichester, UK: John Wiley & Sons, Ltd, pp. 212-234.
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