Identification of apomorphies and the role of groundpatterns in molecular systematics

• Published in: Journal of zoological systematics and evolutionary research Vol. 34; no. 1; pp. 31 - 39
• Main Author: Wägele, J.-W.
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01.03.1996
• Subjects: apomorphy; character analysis; maximum parsimony; molecular systematics; neighbour joining; phylogenetic signal; phylogenetic systematics; split decomposition
• ISSN: 0947-5745; 1439-0469
• DOI: 10.1111/j.1439-0469.1996.tb00807.x

Putative apomorphic character states are the only relevant phylogenetic signal contained in sets of sequence data. Using the sequence position as a character, a way to identify putative apomorphies prior to phylogenetic analysis is proposed. It is shown that distance‐matrix methods use trivial characters. The concept of the asymmetrical split is presented for determination of character polarity. It is furthermore argued that groundpatterns (node sequences) should be reconstructed prior to the study of relationships between taxa of high phylogenetic age. The ‘evolutionary noise’contained in groundpatterns can be illustrated with a network of distances using a split‐decomposition analysis.