Researchers are collecting vast amounts of diverse genomic data with ever-increasing speed, but effective ways to visualize these data in an integrated manner have lagged behind the ability to generate them.

Until a decade ago, scientists categorized microorganisms almost exclusively by their physical characteristics: how they looked, what they ate, and the by-products they produced. With the advent of genomic sequencing and genetic analysis in the 1990s, our understanding of the relationships between different microorganisms fundamentally changed. In light of this new knowledge, what exactly is the definition of a microbial species, and how should microbiologists be categorizing microorganisms?