A Universal Microbial Clock for Estimating the Postmortem Interval Metcalf Fly Data

Vertebrate corpse decomposition provides an important stage in nutrient cycling in most terrestrial habitats, yet the community assembly and metabolic properties governing change during decomposition are poorly understood. Here we use a combination of deep microbial community characterization, community-level metabolic reconstruction, and soil biogeochemical assessment to understand principles governing microbial community changes during decomposition of mouse and human corpses on different soil substrates. We find a suite of bacterial and fungal groups contributing to nitrogen cycling and a reproducible network of decomposers that emerge on predictable timescales using a Bayesian network approach. The results show this decomposer community derives primarily from bulk soil, but key members also originate from insects and other sources. Soil type was not a dominant factor driving community development and the process of decomposition is sufficiently reproducible that microbial investigation of corpses and gravesoils may be useful in medicolegal death investigations.