User:EdJohnston/Cladistics improvement

Page for collecting new material for the Cladistics article, currently listed at WP:FARC

In the article, the term 'Cladistics' falls from the sky. The laconic phrase is "Willi Hennig (1913-1976) is widely regarded as the founder of cladistics." In fact the term 'cladistics' was applied to Hennig's ideas by later workers. Hennig's own work goes as far back as 1936, and he published the first complete book that enunciated his principles (in German) in 1950. Hennig's term for what he was doing was 'phylogenetic systematics', as you can easily determine from the German title. The term 'clade' was introduced by Julian Huxley in 1958. There was a key paper by Cain and Harrison (1960), "Phyletic weighting". Later workers such as Claude Dupuis attribute the origin of 'clade' to 19th century biologists, but this ancestry may not be too relevant because many of the people working around 1960 seem not to have been aware of it.

Dupuis (1984) offers this data point to show Hennig's influence: "Since Hennig's death [in 1976], as many as 1000 books and papers illustrating or discussing his thought have been published."

Cladistics as a post-Hennig movement

The English translation of an extensively-revised version of Hennig (1950) appeared in 1979, after Hennig's death. Donn Rosen, Gareth Nelson and Colin Patterson wrote a Foreword that included this statement:

"Encumbered with vague and slippery ideas about adaptation, fitness, biological species and natural selection, neo-Darwinism (summed up in the 'evolutionary' systematics of Mayr and Simpson) not only lacked a definable investigatory method, but came to depend, both for evolutionary interpretation and classification, on consensus or authority." (Foreword page ix).

Later they continued (page x): "It is clear, at least to us, that cladistics is the general method of historical science." These authors were using a term, 'cladistics', that did not appear in the index of Hennig (1979). In other words, it was not an term that Hennig used for his own approach.

Lack of crisp definitions

The authors themselves appear not to define their terms sharply. What's a synapomorphy? What's an outgroup?

Runoffs possible?

You can imagine in principle that a given data set could be analyzed by two competing methods. In computational phylogenetics this is indeed possible. You could try a comparison of maximum parsimony and maximum likelihood on the same data, and see what trees were produced. The descriptions of their methods by these authors don't seem clear enough to permit that.

New references

A.J.Cain and G.A.Harrison. "Phyletic weighting". Proceedings of the Zoological Society of London. 135: 1–31.

Claude Dupuis (1984). "Willi Hennig's impact on taxonomic thought". Annual Review of Ecology and Systematics. 15: 1–24. ISSN 0066-4162.

Willi Hennig (1950). Grundzüge einer Theorie der Phylogenetischen Systematik. Berlin: Deutscher Zentralverlag.. Reprinted in 1981 by Königstein, Költz, West Germany.

Willi Hennig (tr. D. Davis and R. Zangerl) (1979). Phylogenetic systematics. Urbana, IL: Univ. of Illinois Press. ISBN 025200745X.

Ernst Mayr (1982). The growth of biological thought: Diversity, evolution and inheritance. Cambridge, MA: Harvard University Press. ISBN 0-674-36446-5.