Pre-registration Required

Monday, July 21, 2008       Time: 8:00 a.m. - 4:00 p.m.

#5 New Directions in Forensic Taphonomy
        - Life After Death

Faculty

Miranda ME Jans, PhD Institute for Geo and Bioarchaeology Vrije Universiteit Amsterdam, Noord Holland 1081HV The Netherlands	David O. Carter, PhD Department of Entomology University of Nebraska-Lincoln Lincoln, NE 68583-0816	Matthew J. Collins, PhD BioArCh, University of York , Biology York YO10 5YW United Kingdom
Franklin E. Damann, MA National Museum of Health and Medicine Walter Reed Army Medical Center Washington, DC 20306-6000	Eva-Maria Geigl, PhD Institut Jacques MONOD, CNRS Universities Paris 6 & 7Paris Cedex 05 75251 France	Thomas M.Gilbert, PhD Department of Biology University of Copenhagen Copenhagen DK-2100 Denmark
Hannah E. Koon, PhD BioArCh, University of York, Biology York YO10 5YW United Kingdom	Odile Loreille, PhD Armed Forces DNA Identification Laboratory Rockville, MD 20850	Gordon Turner-Walker, PhD School of Cultural Heritage Conservation Yunlin National University of Science & Technology Douliou, Yunlin 640 Taiwan

After attending this workshop, attendees will have a better understanding of new developments in forensic taphonomy, specifically early postmortem decomposition, microbially-mediated processes, and the influence of environmental parameters. Furthermore, understanding the influence of taphonomy on the quality of biomolecules, and interpretation of taphonomic signals in osseous material can help improve future sample selection. Strategies for dealing with taphonomically compromised samples will be discussed.

This workshop will impact the forensic community and/or humanity by informing attendees on the wide-ranging possibilities of new taphonomic research in the forensic setting, including the relationships between decomposition, soils, and soil microorganisms.

Forensic taphonomy has been established as a valuable tool in forensic research. Recent studies both in forensic and archaeological taphonomy aim to expand the current knowledge to reveal perimortem history, offer new tools for estimating the post mortem interval and improve sample selection for and recovery of biomolecular information (e.g. DNA).

Decomposition is a vital, yet often overlooked, process for life on Earth. This process contributes to the cycling of carbon and nutrients in all terrestrial ecosystems and is primarily biologically mediated. Several recent studies have shown that the behavior and development of some of the organisms involved in decomposition can contribute to the estimation of post mortem interval, location of clandestine graves, and determination of cause of death. The main factors that regulate decomposition and how they relate to forensic taphonomy will be discussed.

After death, bones and teeth are most resistant to decay and usually survive longest. Studies in archaeological bone decay have shown that biological alteration of the bone structure can already occur within years postmortem, which makes it an interesting subject for forensic taphonomy. Of course, environmental and edaphic parameters influence the (biological) degradation of bone as well, such as rapidly fluctuating water levels and acid soils in a burial site, as will be shown in several case studies and experimental field burials in terrestrial and marine environments.

Enclosed and relatively protected within mineralized tissues are biomolecules, like DNA and proteins. Obviously, the processes that alter bone also influence the preservation and quality of these biomolecules. Biomolecular archaeologists have made progress in their attempts to understand the limits to survival of DNA, lipids and proteins in a variety of different settings and have developed tools to use this information to assess age at death (from the states of protein decay) and predict the likelihood of DNA amplification success. The usefulness of this knowledge for the forensic community will be discussed. Understanding the way in which collagen - the most important protein in bone - breaks down can help to predict the fate of bones in different burial environments. Using TEM, DSC, and amino acid analysis, decomposition of collagen is described, as well as how different burial environments will affect the rate of this process. Forensic research will benefit from what biomolecular archaeologists have learnt about the taphonomy of nucleic acids, lipids, and proteins and the role played by their local and wider survival.

DNA preservation will also be discussed in detail. It can vary as a function of the taphonomical context, but the anatomical location it is extracted from also plays a role. Post recovery DNA degradation is an important factor that must be taken into account, especially in samples that have been stored for a while. However, DNA may well be preserved in molecular niches in degraded samples, where traditional analytical methods fail to recover it. Several approaches, such as high throughput sequencing methods, are described, which enhance reliability and recovery of DNA from degraded forensic or ancient samples, allowing the yield of maximal information of degraded tissue.

Humans are important taphonomic agents, for example through embalming. The goal of embalming is to retard the processes associated with decomposition. Pre-burial treatments, such as synthetic cross-linking and heat treatment, will dramatically alter bone collagen and in doing so not only change the diagenetic trajectory of bone but also influence chances of DNA recovery. A case study, where 865 soldiers from the Korean War were embalmed in the 1950’s will be discussed, describing the current state of the remains and the consequences for their identification.

Arguably, the traditional view of decomposition is that it results in the loss of information on different levels, ranging from macroscopic to molecular. However, we argue that taphonomy also adds valuable information. Deciphering early postmortem history and time since death from these indicators is a valuable approach in forensic research. Moreover increased knowledge of taphonomy in forensic studies can inform about the quality of DNA results, aid in sample selection and improve recovery of biomolecular information.