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a taxonomic and geographic reference (d.r. frost, 1985, allen press and the association of systematics collections) e amphibian species of the world:
a taxonomic and geographic reference (d. r. frost, 1985, allen press and the association of systematics collections) and amphibian species of the world:

cioè gruppi costituiti da poche specie che da sole, e a volte per ammissione degli stessi autori (ibid., 14, 29, 39), non possono mostrare ne’ la quantità dei caratteri, ne’ la qualità degli stessi, per poter essere interpretati some ancestrali o derivati, e quindi poter trarre conclusioni filogenetiche attendibili sui taxa analizzati. un principio che lo stesso hennig sintetizza così: “for phylogenetic systematics this means that the reliability of its results increases with the number of individual characters that can be fitted into trasfomation series” (ibid, 132).
therefore, groups consisting of a few species, which by themselves (sometimes by the author’s own admission, ibid., 14, 29, 39) cannot show quantitative, and qualitative characters, in order to be interpreted as ancestral or derivatives, and then to draw reliable phylogenetic conclusions on the analyzed taxa. a principle that hennig summarizes: “for phylogenetic systematics this means that the reliability of its results increases with the number of individual characters that can be fitted into transformation series” (ibid, 132).