The past 35 years in biological systematics have been a time of remarkable philosophical and methodological developments. For nearly a century after Darwin's Origin of Species, systematists worked to understand the diversity of nature based on evolutionary relationships. Numerous concepts were presented and elaborated upon, such as homology, parallelism, divergence, primitiveness and advancedne...

The core concept of phylogenetic systematics is the use of derived or apomorphic characters to reconstruct common ancestry relationships and the grouping of taxa based on common ancestry. This concept, first formalized by Hennig (1950, 1966), has been slowly, and not so quietly, changing the nature of systematics. Why should we be interested in this approach? What about phylogenetic systematics...

P rions were injected into the public consciousness earlier this year when the British Government’s Health Secretary, Stephen Dorrell, rose in the House of Commons to make his dramatic announcement that the ‘most likely’ explanation for ten cases of a Creutzfeldt-Jakob disease-like (CJD) illness in young people was exposure to British beef that had been infected with the agent causing bovine sp...