Abstract
Microbiology began as a unified science using the principles of chemistry to understand living systems. The unified view quickly split into the subdisciplines of medical microbiology, molecular biology, and environmental microbiology. The advent of a universal phylogeny and culture-independent approaches have helped tear down the boundaries separating the subdisciplines. The vision for the future is that the study of the fundamental roles of microbes in ecology and evolution will lead to an integrated biology with no boundary between microbiology and macrobiology. Expected final online publication date for the Annual Review of Microbiology, Volume 75 is October 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.