In the absence of a molecular species concept, most microbial eukaryotic systematics has been based on morphological data to delineate species, and the characters used have often been restricted to features that are visible with light microscopy.
The difference between patterns in shell morphology and anatomy explains why lymnaeid systematics has been controversial [ 6].
Microbial systematics has been based primarily on the analysis of small subunit ribosomal RNA (16S rRNA) sequences.
Understanding isotope systematics has also proven useful when investigating the effect of human activities on the environment.
The philosophy of systematics has had a major influence on recent work on classification and natural kinds in the general philosophy of science (Dupré 1993; Wilson 1999).
Traditional systematics has assigned these gasteroid taxa to a group of their own, but several studies have proven that at least some hypogeous basidiomycetes share morphological and genetic relations to epigeous sister taxa [6], [7], [8], [9].
Molecular systematics has revolutionized traditional plant systematics and classification.
Red algal systematics has seen many improvements over the past decades.
Even systematics has had to abandon many strictures that were part of the Modern Synthesis.
Amphibian systematics has undergone pronounced changes over the past decade (e.g., [ 17, 18]).
