Almost a half century ago, Alexander (1977) identified nine genera of bacteria that were important in soils. That list included Agrobacterium, Alcaligenes, Arthrobacter, Bacillus, Flavobacterium, Micromonospora, Nocardia, Pseudomonas, and Streptomyces. Today Alexander’s list only represents 2–3% of known soil microorganisms (Janssen 2006) and omits phyla such as Acidobacteria, Planctomycetes, and Verrucomicrobia that are ubiquitous (Delgado-Baquerizo et al. 2018). This discrepancy illustrates the dramatic shift that has taken place in soil microbial ecology due to wide adoption of molecular techniques that has largely replaced culturing to describe communities. Although these techniques have opened entire new lines of inquiry into life within soil, they have also uncovered challenges in our understanding of how microbial communities function within the soil matrix and how we should interpret the vast numbers of organisms that we encounter there.