Difference without distinction? Gaps in cyanobacterial systematics; when more is just too much

Abstract

Cyanobacteria are amongst the most abundant, ubiquitous, ecologically and evolutionarily significant microbes on Earth. Unique among the Bacteria in their capacity to be identified using morphology, understanding the evolutionary relationships and describing the diversity of this lineage is both important and challenging. The advent of modern sequencing technology has proven a boon to those studying cyanobacterial systematics as it has provided copious amounts of sequence data (mainly of the 16S rRNA gene sequence). However, this influx of data has also led to taxonomic confusion and recognition of polyphyly in many genera. Thus, the purpose of this paper is to describe this apparent paradox of increasing data yet poor phylogenetic resolutions by employing the Poisson Tree Process (PTP) algorithm and to propose some ameliorative efforts.