Ethics of DNA research on human remains: five globally applicable guidelines.

We are a group of archaeologists, anthropologists, curators and geneticists representing diverse global communities and 31 countries. All of us met in a virtual workshop dedicated to ethics in ancient DNA research held in November 2020. There was widespread agreement that globally applicable ethical guidelines are needed, but that recent recommendations grounded in discussion about research on human remains from North America are not always generalizable worldwide. Here we propose the following globally applicable guidelines, taking into consideration diverse contexts. These hold that: (1) researchers must ensure that all regulations were followed in the places where they work and from which the human remains derived; (2) researchers must prepare a detailed plan prior to beginning any study; (3) researchers must minimize damage to human remains; (4) researchers must ensure that data are made available following publication to allow critical re-examination of scientific findings; and (5) researchers must engage with other stakeholders from the beginning of a study and ensure respect and sensitivity to stakeholder perspectives. We commit to adhering to these guidelines and expect they will promote a high ethical standard in DNA research on human remains going forward.

Forensic taphonomic experimental design matters: a study assessing clothing and carrion biomass load on scavenging in Cape Town, South Africa.

The identification of unknown human remains is a significant and ongoing challenge in South Africa, worsened by the country's high murder rate. The rate of decomposition in South Africa is significantly influenced by vertebrate scavenging, which, if not considered, can impede the accurate estimation of the post-mortem interval. Scavenging patterns vary greatly depending on the environment and ecological region, and there is limited data for the Western Cape province. To address this gap, two clothed and uncaged pig carcasses weighing 60 kg each were placed in the field in July 2021 and January 2022, respectively. Motion-activated infrared-capable trail cameras were used to observe decomposition, scavenger species, and their activities. Additionally, a comparative sample of 16 unclothed carcasses deployed between 2014 and 2016 in the same habitat were analyzed to assess the impact of clothing and biomass load. The study found three main results: (1) Regardless of habitat or biomass load, it took significantly less time to reach decomposition milestones (25%, 50%, and 75%) during the summer season; (2) the presence of mongoose scavengers had a greater impact on the time required to reach milestones during winter compared to summer; and (3) single carcass deployments reached the milestones faster than multi-carcass deployments in both seasons. This research highlights the potential inaccuracy of current methods for estimating the post-mortem interval when scavenging activity is not considered or documented in the underlying experimental data, particularly for environments or ecological biomes where scavengers actively impact decomposition rates.

The evolution and changing ecology of the African hominid oral microbiome.

The oral microbiome plays key roles in human biology, health, and disease, but little is known about the global diversity, variation, or evolution of this microbial community. To better understand the evolution and changing ecology of the human oral microbiome, we analyzed 124 dental biofilm metagenomes from humans, including Neanderthals and Late Pleistocene to present-day modern humans, chimpanzees, and gorillas, as well as New World howler monkeys for comparison. We find that a core microbiome of primarily biofilm structural taxa has been maintained throughout African hominid evolution, and these microbial groups are also shared with howler monkeys, suggesting that they have been important oral members since before the catarrhine-platyrrhine split ca. 40 Mya. However, community structure and individual microbial phylogenies do not closely reflect host relationships, and the dental biofilms of Homo and chimpanzees are distinguished by major taxonomic and functional differences. Reconstructing oral metagenomes from up to 100 thousand years ago, we show that the microbial profiles of both Neanderthals and modern humans are highly similar, sharing functional adaptations in nutrient metabolism. These include an apparent Homo-specific acquisition of salivary amylase-binding capability by oral streptococci, suggesting microbial coadaptation with host diet. We additionally find evidence of shared genetic diversity in the oral bacteria of Neanderthal and Upper Paleolithic modern humans that is not observed in later modern human populations. Differences in the oral microbiomes of African hominids provide insights into human evolution, the ancestral state of the human microbiome, and a temporal framework for understanding microbial health and disease.

Clinical and Anthropological Analyses of a Case From 19th Century South Africa With a Confluence of Uncommon Cranial Pathological Conditions.

This study combines clinical and anthropological analyses to investigate the complex cranial pathology of a South African individual from the 19th century. The cranium was examined macroscopically and radiographically. Conducting a standard differential diagnosis was challenging given the complexity and uncommon nature of the pathology and required drawing on relatively sparse paleopathological and clinical case reports. Multiple conditions were identified including biparietal thinning, basilar invagination, platybasia, and complicated chronic frontal sinusitis, where the intracranial extension of sinus infection may likely have contributed to the individual's death. The authors urge for awareness of these uncommon conditions, as their presence can easily be overlooked or confound skeletal assessments. This clinical study contributes to the authors' understanding of uncommon and poorly described paleopathological diseases and will help to better facilitate their diagnosis in future research. It represents one of the first studies describing such an unusual cooccurrence of uncommon pathologies in an archeological individual.

Forensic human identification: retrospective investigation of anthropological assessments in the Western Cape, South Africa.

The identification of unknown persons, particularly those who are decomposed or burnt, is a global challenge. Forensic Anthropology Cape Town (FACT) is a service provider that assists the South African state with the identification of human remains. However, empirical data pertaining to anthropologically analysed forensic cases in the Western Cape Province of South Africa are lacking. Therefore, anthropological data pertaining to the forensic cases submitted to FACT between 2006 and 2018 from Forensic Pathology Services were retrospectively reviewed (n = 172). This study also sought to assess demographic, traumatic and pathological factors that impacted successful identification. Most decedents were male (67%) and older than 35 years (54%). While ante-mortem trauma was observed in 41% of decedents, the lack of medical records on ante-mortem injuries hindered the use of this information for identification. Positive identifications were reached for 37% of decedents, and of these, anthropological estimations were correct in 98% of cases for sex, 84% of cases for age at death and 100% of cases for stature. Considering globally accepted accuracies of 70-80%, these estimations were considered highly accurate, suggesting the anthropological methods used are suited to the population. However, 63% of cases remained unidentified, and this study showed that skeletal completeness and pathological conditions were the main factors that hindered demographic estimations. Lastly, not all unidentified bodies in the province were referred to FACT; given the highly accurate estimations, these data advocate for the routine, if not mandatory, use of forensic anthropology services for skeletonised remains in South Africa, with the overall purpose of positively impacting human identification. To improve identification rates globally, these data highlight the value of retrospective and region-specific studies to identify strengths and weaknesses in the system.

Restitution versus repatriation: Terminology and concepts matter.

INTRODUCTION: Through museum collecting practice, the deceased, possessions, plants and animals were turned into objects, removed from their communities and places of origin, and were segregated and divided into museum classificatory systems. In the decolonial work of embarking upon purposeful and proactive acts of return, the terms "repatriation" and "restitution" have often been used interchangeably. OBJECTIVE: To assess the terminological differences between repatriation and restitution. METHODS: Here, we critically discuss the politics of these terms and present an argument for restitution as restitutionary work. RESULTS: Repatriation refers to the legal, administrative and logistical matters of returning across national borders. However, restitution is a preferred concept highlighting deeper meanings of return to the proper owner, with restitutionary work being time-consuming, emotional, often painful, enriching acts of restoration, and transitional justice. Restitution is about the embodiment and empowerment of choice over all aspects of the return. CONCLUSION: Here, we argue that terminology matters. While restitution may involve repatriation, repatriation is not a substitute for acts of restoration embodied in restitutionary work.

Entheseal changes and activity patterns in southern African hunter-gatherer/herders from the Holocene.

OBJECTIVES: Activity patterns and lifeways in southern African hunter-gatherer/herders (sAHGH) during the Holocene were dynamic, with subsistence activities and mobility varying through space and time. In this study, spatial and temporal variations in entheseal changes (ECs) are assessed as physical activity markers in sAHGH from the Holocene. METHODS: The Coimbra method was used to assess fibrocartilaginous ECs in the upper and lower limbs of 118 sAHGH from the Holocene. Descriptive statistics and generalized estimating equations were used to explore the association between ECs, sex, age, ecological biomes, and temporality. RESULTS: A total of 118 individuals were sampled, comprising 67 males, and 42 females, mostly from the fynbos (59/118), forest (30/118) and succulent karoo biomes (16/118). ECs were identified in 94% of the sample. Interobserver scoring suggests our findings are likely to underrepresent the extent of EC score differences in sAHGH. Findings indicate a complex pattern of physical activity in sAHGH with differences attributable to regional ecology rather than age or sex. More prominent ECs were identified in individuals from the forest biome, relative to the fynbos and succulent karoo biomes. These were consistent with resource search and processing costs, and terrain differences in these ecozones. ECs were only detected temporally relative to the infiltration of pastoralism (at 2000 BP) when the data were stratified by ecological biome. DISCUSSION: This study provides evidence that regional ecology plays a central role in driving activity patterns regardless of social or cultural organization. Ecological biomes provide a gradient along which the temporal impact of resource limitations on human biology, activity patterns and sociocultural behaviors can be studied.

Portion size matters: Carrion ecology lessons for medicolegal death investigations-A study in Cape Town, South Africa.

Forensic taphonomic studies are regionally specific and improve time since death estimates for medico-legal casework. Within forensic taphonomy and carrion ecology, vertebrate scavengers are under-researched with many studies conducted using multiple, unclothed carcasses. This is a forensically unrealistic experimental design choice with unknown impact. The effect of variation in carrion biomass on the decomposition ecosystem, particularly where vertebrate scavengers are concerned, requires clarification. To assess the effect of carrion biomass load on vertebrate scavenging and decomposition rate, seasonal baseline data for single, clothed ~60 kg porcine carcasses were compared to clothed multiple-carcass deployments, in a forensically relevant habitat of Cape Town, South Africa. Decomposition was tracked via weight loss and bloat progression and scavenging activity via motion-activated cameras. The single carcasses decayed more quickly, particularly during the cooler, wetter winter, strongly correlated with concentrated Cape gray mongoose (Galerella pulverulenta) scavenging activity. On average and across seasons, the single carcasses lost 68% of their mass by day 32 (567 accumulated degree days [ADD]), compared to 80 days (1477 ADD) for multi-carcass deployments. The single carcasses experienced substantially more scavenging activity, with longer visits by single and multiple mongooses, totaling 53 h on average compared to 20 h for the multi-carcass deployments. These differences in scavenging activity and decay rate demonstrate the impact of carrion biomass load on decomposition for forensic taphonomy research. These findings need corroboration. However, forensic realism requires consideration in taphonomic study design. Longitudinally examining many single carcasses may produce more forensically accurate, locally appropriate, and usable results.

Anatomical human body donation in South Africa: Inconsistencies of informed consent.

INTRODUCTION: Informed consent is critical for maintaining the ethical standards associated with the utilization of human donor bodies by tertiary education institutions. Body donation programs undertake the responsibility for procuring human donor bodies for didactic and research purposes. However, its processes require scrutiny regarding best practice guidelines and the South African National Health Act (SA-NHA) (2013). Moreover, acknowledging and addressing the current perceptions of human body donation are indispensable in bridging the gap between academia and society. This study aimed to compare informed consent documentation and procedures across South African tertiary education institutions and their affiliated human body donation programs (HBDP) in accordance with international guidelines. The findings were used to create a human body donation form template aligned to current international best practices for consideration by the South African HBDP. METHODOLOGY: A review of information and consent forms collected from South Africa's eight HBDP was conducted. The analyses consisted of a broad evaluation of information provided, ranging from the terms-of-use for human donor bodies to the commitments made by HBDP to body-donors. The results were considered in conjunction with the International Federation of Associations of Anatomists and other recent publications on informed consent in HBDP. RESULTS: Only two of the eight HBDP provided information and consent forms in more than one language. Most allowed donors to select how their bodies will be utilized - education, training and/or research. Some (6/8) made provisions for the next-of-kin to receive the cremains. Only one tertiary educational institution mentioned the occurrence of a memorial service in its documentation. An HBDF template was created aligned to current international best practices for presentation and possible adaption by SA HBDP. DISCUSSION & CONCLUSIONS: Human body donation forms (HBDF) requires thorough examination for the promotion and sustainability of HBDP. Effective communication by employing standardized non-technical terminology conveyed in language that is understandable and native to potential donors facilitates the deliverance of informed consent. Inconsistencies regarding the use and management of bodies catalyze the weakening perception of human body donation. Thus, this process of securing informed consent for body donation should be conducted in conjunction with public awareness campaigns and underpinned by the necessary policy and legislative reform.

A South African case study on anatomical embalming for human body donation programmes with toxicological considerations.

Body embalming, a practice with deep historical roots across various cultures, forms the backbone of contemporary human body donation educational programmes. In this study, we explored current embalming practices within six South African human anatomical dissection programmes, focusing on the use and volumes of key chemicals-formalin, phenol, and alcohol-and their associated health risks and potential toxicity. We measured and compared aspects of embalming practices such as the duration of body preservation and the annual intake of bodies. Variations in embalming practices and chemical ratios across different South African universities were found. However, the consistent use of formalin, phenol and alcohol were observed across all six programmes. Formaldehyde concentrations used in South African dissection programmes were within the generally acceptable international range. Regarding arterial embalming, South African dissection programmes showed widespread adherence to international embalming practices, with one programme using a substantially lower concentration of formalin. The dual nature of formaldehyde as both an effective preservative and a recognised carcinogen was underscored in relation to human health regarding chemical toxicity. Phenol, like formaldehyde, was consistently used as it is important for the inhibition of bacterial and fungal growth. Alcohol was also consistently used, but there was much greater variation in its volume across South African institutions. Our data showed a slight positive relationship between storage duration and the volumes of formalin and phenol in human embalming fluid. South African regulators enforce stricter exposure limits than those set by the World Health Organisation and various European agencies. While South African institutions operate within internationally acceptable ranges of chemical use that both maximise preservation and minimise toxicity, we acknowledge that these data are preliminary. Further investigation is encouraged to ensure embalming practices effectively protect all those involved and support the educational goals of human anatomical dissection programmes in South Africa.

Informing regional taphonomy research using retrospective forensic anthropology cases in the Western Cape, South Africa.

The post-mortem interval (PMI) is important in death investigations as it can assist in reconstructing the context of the case and the identification of the unknown individual. However, in some instances the PMI is challenging to estimate due to the absence of regional taphonomy standards. To conduct accurate and locally relevant forensic taphonomy research, investigators require insight into the regional hotspot recovery areas. Thus, forensic cases examined by the Forensic Anthropology Cape Town (FACT) in the Western Cape (WC) province of South Africa between 2006 and 2018 (n = 172 cases; n = 174 individuals) were retrospectively reviewed. In our study, a considerable number of individuals did not have the PMI estimations (31 %; 54/174) and the ability to estimate a PMI was significantly associated with skeletal completeness, unburnt remains, absence of clothing and the absence of entomological evidence (p < 0.05 for each). Significantly fewer cases had the PMI estimated after FACT was formalised in 2014 (p < 0.0001). One third of cases with PMI estimations were made with large open-ended ranges, making them less informative. Factors significantly associated with these broad PMI ranges were fragmented remains, absence of clothing and absence of entomological evidence (p < 0.05 for each). Most decedents (51 %; 87/174) were discovered in police precincts from high crime areas, yet a considerable number (47 %; 81/174) were also found in low crime and sparsely populated areas regularly used for recreational activities. Common sites of body discovery were vegetated areas (23 %; 40/174), followed by the roadside (15 %; 29/174), aquatic environments (11 %; 20/174) and farms (11 %; 19/174). Decedents were discovered exposed (35 %; 62/174), covered with items such as bedding or shrubs (14 %; 25/174) or buried (10 %; 17/174). Our data highlight gaps in forensic taphonomy studies and clearly informs what regional research is needed. Overall, our study demonstrates how forensic case information can inform regional forensic taphonomy studies to locate common areas and contexts for the discovery of decomposed bodies and encourages similar studies in other areas of the world.

Traumatic cubitus valgus consequent of distal humeral fracture: Two case studies from the Holocene Later Stone Age in southern Africa.

OBJECTIVES: Distal fractures of the humerus and their complications have rarely been described or analysed in the palaeopathological literature. The objective of this study was to evaluate two cases of distal humeral fracture with associated cubitus valgus observed in two individuals from the context of the Later Stone Age (LSA) in southern Africa. MATERIALS: Skeletal remains of two individuals. A middle-aged female radiocarbon dated to c.160 BP and a middle-aged male radiocarbon dated to c.2 300 BP. METHODS: Remains were macroscopically and radiographically assessed for injury. RESULTS: Both cases presented with healed antemortem injury to the right elbow attributed to possible falls. Distal humeral fracture resulted in non-union of the lateral epicondyle with extensive morphological changes to the elbow joint including an increased carrying angle. Morphological and osteoarthritic changes suggest a survival period of several years post-injury. SIGNIFICANCE: Cubitus valgus following traumatic injury has rarely been reported amongst historic or prehistoric populations. The described injuries would have had physical and functional consequences, raising questions relating to probable care received during the healing process. The elbow injuries would have resulted in restricted motion and instability of the elbow joint, with a high likelihood of ulnar neuropathy. LIMITATIONS: The contextual information for these individuals is limited and do not permit broader population level study. SUGGESTIONS FOR FURTHER RESEARCH: Formal biomechanical analysis including cross-sectional geometry analysis will provide further information regarding complications and strengthen the diagnosis of ulnar neuropathy. Further research is necessary on the prevalence and complications of humeral fracture.

Bilateral hip dysplasia in a South African male: A case study from the 17-18th century.

OBJECTIVE: To identify, critically analyse and describe severe bilateral skeletal pathology involving the ossa coxae of an individual from historic era Cape Town. MATERIALS: A single individual from the University of Cape Town's Human Skeletal Repository was analysed under research approval (HREC# 035/2021). METHODS: An osteobiography was constructed, radiocarbon dating and isotopic analyses were conducted. Pathological description and contextualised disability analyses followed, along with differential diagnosis. The pelvis and femora were visualised macroscopically and radiographically. RESULTS: This individual was a non-European middle-aged adult male who lived in the 17-18th centuries CE. Morphological changes showed hypoplastic hips with collapsed femoral heads and neoacetabulae. A diagnosis of developmental dysplasia of the hips (DDH) was made. Then a contextualised disability analysis including consideration of the clinical and functional impacts of the condition were applied. No signs of maltreatment, physiological stress or persistent infections were present. His bones were well developed, illustrating mobility and use. CONCLUSIONS: He developed DDH early in life and lived through adulthood, and his strong, healthy bones suggest resilience, some mobility and contribution to society through less physically demanding tasks. SIGNIFICANCE: Value for palaepathological analyses to inform and understand disability and culturally significant health mediation to offer a more objective interpretation and improve understanding of past people. It expands our understanding of the presence of DDH globally and in Africa and provides insight into disease impact for individuals with bilateral expression. SUGGESTIONS FOR FUTURE RESEARCH: Further contextual research is required. LIMITATIONS: Poor scene recovery hindered in-depth care analysis and interpretation of the condition.

Confronting historical legacies of biological anthropology in South Africa-Restitution, redress and community-centered science: The Sutherland Nine.

We describe a process of restitution of nine unethically acquired human skeletons to their families, together with attempts at redress. Between 1925-1927 C.E., the skeletonised remains of nine San or Khoekhoe people, eight of them known-in-life, were removed from their graves on the farm Kruisrivier, near Sutherland in the Northern Cape Province of South Africa. They were donated to the Anatomy Department at the University of Cape Town. This was done without the knowledge or permission of their families. The donor was a medical student who removed the remains from the labourers' cemetery on his family farm. Nearly 100 years later, the remains are being returned to their community, accompanied by a range of community-driven interdisciplinary historical, archaeological and analytical (osteobiographic, craniofacial, ancient DNA, stable isotope) studies to document, as far as possible, their lives and deaths. The restitution process began by contacting families living in the same area with the same surnames as the deceased. The restitution and redress process prioritises the descendant families' memories, wishes and desire to understand the situation, and learn more about their ancestors. The descendant families have described the process as helping them to reconnect with their ancestors. A richer appreciation of their ancestors' lives, gained in part from scientific analyses, culminating with reburial, is hoped to aid the descendant families and wider community in [re-]connecting with their heritage and culture, and contribute to restorative justice, reconciliation and healing while confronting a traumatic historical moment. While these nine individuals were exhumed as specimens, they will be reburied as people.

Metastatic cancer along ancient Silk Road: A possible case from Xinjiang (China).

OBJECTIVE: Palaeopathological evidence of cancer, especially metastatic cancer, is rare in China. This paper describes and diagnoses a cranium with multiple lytic lesions recovered from the Sampula cemetery in Xinjiang, attempting to diagnose the type of disease that could have caused the pathological lesions observed. MATERIAL: A cranium from an adult male (#00106) was recovered from the Sampula cemetery (dated to 55 BCE to 335 CE) located in the Luopu County, the Hotan River oasis on the southern edge of the Tarim Basin in southern Xinjiang. METHODS: The cranium was assessed macroscopically and radiographically (CT). RESULTS: Multiple osteolytic lesions with irregular and "moth-eaten" margins were detected in cranium #00106. CT scans revealed the development of the lesions began at the diploe and identified a "button sequestrum". CONCLUSIONS: Based on lesion characteristics, metastatic carcinoma was likely the cause of lesions found in cranium #00106. SIGNIFICANCE: This case has expanded our knowledge of the malignant neoplasms of ancient populations in northwest China and discusses the possible risk factors in the occurrence of cancer in the Sampula site, as well as the possible impacts of skeletal metastases on the individual. LIMITATIONS: The distribution of osteolytic lesions over the complete skeleton cannot be observed because of the unavailability of postcranial bone. SUGGESTIONS FOR FUTURE RESEARCH: With the increasing number of reports describing diseases in ancient China, the patterns of diseases occurrence and development can be further explored from spatial and temporal perspectives.

Pressing need for national governmental recognition of forensic anthropology in South Africa as illustrated in a medico-legal case.

Forensic anthropology in South Africa is well developed in the higher education sector, with advanced training and research programmes. Despitethis and decades of academic involvement in casework, forensic anthropology still lacks a defined framework and mandate ata governmentallevel. Therefore, the involvement of forensic anthropologists' expertise varies markedly between cases, provinces, and among various stakeholderswithinthe country, to the detriment of dispensation of social and criminal justice. The lack ofclearly defined guidelines for the renderingof the service was exemplified and demonstrated through a recent forensic case. Here,contextual information was absent, and the remains posed a challenge to analyse, ostensibly due tomissing information. Numerous questions were raised during the analysis of the remains, and broader concerns about the investigative involvement of a forensic anthropologist within South African casework were brought to the fore. Through the analysis of this case, we describe the deductive processes that led to the formation of an opinion that the skeletal linear defects were the result of taphonomic changes. In addition, we highlighthow these efforts where constrained and each step in theprocess unnecessarily hindered. Finally, we demonstrate the capacity andwillingness offorensic anthropology practitioners to be involved, and how, withoutgovernmentalsupport, it is a great potential lamentably untapped.

UCT Human Skeletal Repository: Its stewardship, history, composition and educational use.

The University of Cape Town (UCT) Human Skeletal Repository began in 1913 and its composition a century later reflects the history of biological anthropology at the University, in South Africa and internationally. It consists of 1059 skeletons from archaeological (472; 44%), cadaveric (372; 36%) and forensic contexts (160; 14%). They are used for educational and research purposes to provide engaged scholarship and experiential learning for undergraduate and postgraduate students from a variety of disciplines including health professionals. The cadaveric remains help build population specific standards, forensic cases assist to address social and criminal justice, and the archaeological discoveries to preserve African culture and heritage. Overall, the repository provides a distinct contribution to knowledge locally and globally. The new management approach of the repository is presented. Ethical considerations and management policies are discussed. Stewardship of these individuals is facing several challenges and there are areas that continue to require attention. UCT is committed to address past unethical procurement of remains through engaging with the relevant interested and affected parties in restitution and repatriation.

Forensic human identification: Investigation into tooth morphotype and DNA extraction methods from teeth.

When a body is decomposed, hard tissues such as teeth may provide the only DNA source for human identification. There is currently no consensus as to the best DNA extraction method, and there is a lack of empirical data regarding tooth morphotype and condition that may impact DNA recovery. Therefore, this study sought to investigate which variables significantly improved DNA concentration, integrity and profiling success. A total of 52 human teeth were assessed, representing all tooth morphotypes from three deceased individuals. DNA was extracted using both the QIAamp® DNA Investigator Kit and the phenol-chloroform method. DNA concentration and degradation index were assessed using real time PCR, prior to conventional DNA profiling. Contrary to international guidelines promoting the use of molars, DNA profiling from molars was the least successful, with premolars, followed by canines, performing the best. The presence of fillings reduced the DNA quantity and quality obtained and may explain the poor performance of molars. DNA from the maxillae were significantly less degraded when the QIAamp® was used, although this did not influence DNA profiling success. A significant increase in DNA concentration, integrity and profiling success was observed in diseased teeth (periodontitis) compared to those without disease. This may be due to increased white blood cell presence at the site. There was no significant difference in DNA profiling success between the two DNA extraction methods. However, different teeth yielded failed DNA profiles for each extraction method, suggesting that repeated attempts, using alternative DNA extraction methods, is recommended. The recovery of additional DNA profiling information from degraded samples may help to ultimately reduce the burden of unidentified human remains.

A review of experimental design in forensic taphonomy: moving towards forensic realism.

Forensic taphonomy as a discipline requires standardization to satisfy Daubert criteria for scientific data to be admissible in court. In response, there has been a shift towards quantification of methodology and estimating the postmortem interval. Despite these advances, there are still biases and limitations within the discipline not explicitly addressed in the early stages of experimental design nor in final published works. In this article, unresolved debates with respect to the conductance and reporting of forensic taphonomic research are reviewed, beginning with the nature of experimental cadavers, human or animal analogues and their body size, and second, the forensic realism of experimental setups, specifically with respect to caging, clothing and number of carcases. Pigs, albeit imperfect, are a good model to gain a general idea of the trends that may be seen in humans in subsequent validation studies in facilities where human donors are available. To date, there is no consensus among taphonomists on the extent of the effect that body mass has on decomposition progression. More research is required with both human cadavers and non-human analogues that builds on our current knowledge of forensic taphonomy to answer these nagging questions. This will enable the discipline to make the reliable assumption that pigs and donor decomposition data can be applied to homicide cases. A suite of experimental design aspects is suggested to ensure systematic and standardized data collection across different biogeoclimatic circumstances to identify and quantify the effects of potential confounding variables. Such studies in multiple, varied biogeographic circumstances with standardized protocols, equipment and carrion will facilitate independent global validation of patterns. These factors are reviewed to show the need for adjustments in experimental design to ensure relevance and applicability of data within locally realistic forensic situations. The initiation of a global decomposition data network for forensic taphonomists is recommended.Key pointsPigs are a valuable, albeit imperfect, proxy for human decomposition studies.There are few or conflicting data on effects of carcase size, carrion ecology, exclusion cages and scavengers.We recommend single, clothed, uncaged carcases for baseline research to reflect regionally specific forensic casework.