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Human Decomposition: A Mosaic Model for Community Succession and Implications for Future Forensic Research

NCJ Number
255313
Date Published
September 2016
Length
20 pages
Annotation

This research project tested microbial community structure and its change over time or succession in human cadavers.

Abstract

The project tested the overall hypothesis that bacterial species communities change over time and ultimately modulate the speed and mode of decomposition. The following hypotheses were tested: 1) Decomposition varies due to successive changes in bacterial species guilds (complexes of species in an ecosystem that exploit the same resources) that inhabit the cadaver after death and colonize the cadaver postmortem; 2) Gases emanating from the cadaver are a byproduct of bacterial metabolism; 3) Fly species attracted to or repelled by the cadaver are responding to gases from the cadaver; and 4) Microbial soil composition beneath a cadaver changes over time. Cadavers were placed outdoors to decompose under natural conditions at the Southeast Texas Applied Forensic Science facility. Results thus far are reported for shifting bacterial community structure, fly-associated bacteria, and volatile organic compounds emitted during decomposition. Data have been collected on approximately 10,000 bacterial, VOC, and insect samples, with only a fraction having been sequenced and/or identified. The research team is working on developing an internet database ("Virtual Museum") that details microbial succession. To date, the research team has published five papers and made 51 presentations. Other papers are being prepared. 10 figures and 2 tables

Date Published: September 1, 2016