Discovery and Classification of Ecological Diversity in the Bacterial World: The Role of DNA Sequence Data

TLDR

Gene sequence similarity groups organisms into discrete clusters, and evolutionary theory predicts each bacterial cluster represents a distinct ecological population. Protein‑coding gene sequence surveys and similarity clustering are proposed as primary tools for identifying and delineating new bacterial ecological populations. Empirical surveys confirm that protein‑coding gene sequence clusters align with ecological bacterial populations.

Abstract

All living organisms fall into discrete clusters of closely related individuals on the basis of gene sequence similarity. Evolutionary genetic theory predicts that in the bacterial world, each sequence similarity cluster should correspond to an ecologically distinct population. Indeed, surveys of sequence diversity in protein-coding genes show that sequence clusters correspond to ecological populations. Future population surveys of protein-coding gene sequences can be expected to disclose many previously unknown ecological populations of bacteria. Sequence similarity clustering in protein-coding genes is recommended as a primary criterion for demarcating taxa.