ABSTRACT
Most of the biodiversity on earth is microbial. These microbes provide important functions for the planet, ranging from cycling of nutrients through the environment to metabolizing food within animal digestive tracts. Although we often associate the term “microbe” with bacteria, microbes are actually found in all three domains of life-bacteria, archaea, and eukaryotes (Woese et al. 1990; Pace 1997). Of the over 70 major eukaryotic groups, most of them are so small as to be invisible to the human eye (Keeling et al. 2005; Parfrey et al. 2006, 2011; Adl et al. 2012), and animals and plants only account for a small fraction of eukaryotic diversity. The ecology of any system, including decomposing carrion, thus requires consideration of the full tree of life because organisms from every domain may be contributing and interacting (described in Chapter 20 by Wood and colleagues).
