Merriam-Webster on cladistics
Google indexed this page today from the online version of Merriam-Webster dictionary:
Main Entry: cla·dis·tics
Pronunciation: \kl?-?dis-tiks, kla-\
Function: noun plural but singular in construction
Date: 1965: a system of biological taxonomy that defines taxa uniquely by shared characteristics not found in ancestral groups and uses inferred evolutionary relationships to arrange taxa in a branching hierarchy such that all members of a given taxon have the same ancestors
— cla·dist \?kla-dist, ?kl?-\ noun
— cla·dis·tic \kl?-?dis-tik, kla-\ adjective
— cla·dis·ti·cal·ly \-ti-k(?-)l?\ adverb
I don’t know when was this entry actually added to the dictionary, but it is nicely defined.

2 Comments to Merriam-Webster on cladistics
You find? I see it as problematic for one reason: the use of the term “ancestral groups”. In other words: paraphyletic groups.
At any rate, it appears to claim that the date of entry was in 1965. That’s a very interesting date for the term to have been introduced to an English dictionary.
In the context of the definition “not found in ancestral groups” clarifies that the shared characteristics must be unique to the taxon been defined. Plesiomorphies won’t do for example. I can live with that.
The date refers to the paper by Ernst Mayr where he first used the term cladistics to label Hennig’s phylogenetic systematics:
Mayr, E. 1965. Numerical phenetics and taxonomic theory. Systematic Zoology 14:73-97.

June 18, 2010