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THE MYTH OF OBJECTIVITY—POST‐HENNIGIAN DEVIATIONS
Author(s) -
SÆTHER OLE A.
Publication year - 1986
Publication title -
cladistics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.323
H-Index - 92
eISSN - 1096-0031
pISSN - 0748-3007
DOI - 10.1111/j.1096-0031.1986.tb00438.x
Subject(s) - synapomorphy , biology , taxon , subfamily , evolutionary biology , parallelism (grammar) , cladogram , zoology , phylogenetic tree , paleontology , computer science , cladistics , clade , biochemistry , parallel computing , gene
Abstract— The punctuated equilibrium speciation mode is an implied consequence of the deviation rule and the differences between cladograms and phylogenetic trees implicitly were recognized by Hennig. Neocladism and transformed cladism, however, both are contradictory to the view of Hennig. Neither of them will be consistent when parallel changes exceed informative unparallel changes, which in the real world there are many indications to believe they do. In three tables cladogenetic trends used in erecting three schemes of argumentation, on the specific, generic, and subfamily levels respectively, are analyzed and divided into: “ objective” synapomorphies not allowing for outside parallelism or secondary change, subjective synapomorphies , and underlying synapomorphies . Evaluations based on the strictest criteria for asserting synapomorphy are possible only when comparing higher taxa of subfamily level and up. On the generic level trends showing outside parallelism can be rejected if all other possibly synapomorphic trends are included. On the specific level it is necessary to take all kinds of synapomorphies into consideration, including those showing outside parallelism. There may often be a preponderance of trends caused by parallel selection in taxa with specialized sexual and/or feeding behaviors, as exemplified by some chironomid male imagines and larvae. It is necessary to have knowledge of the nature of the different possible natural processes and try to explain these before undertaking estimations of patterns of kinship. The persistent intuitive and subjective element in phylogenetics was stressed by Hennig. Objectivity is a myth.