Phenogrammes d’anoures basés sur la morphométrie

Abstract

The author describes some experiments in the morphometry of amphibians. Combining his usual method (LAURENT 1955, 1967) with some of the clustering techniques described by SNEATH & SoKAL (1973), he constructed phenograms which sometimes agree and sometimes partly disagree with the recognized and well-established relationships. Two factors seem involved in such successes and failures. One is the number of measurements used: few data on one hand or redondant characters on the other tend to alter the phenetic distances. Major ecological shifts are also a cause of distortion because they generally entail important and rapid morphometric changes. However, within a definite adaptation zone, the method appears to be sufficiently reliable for the investigation of phylogenetic relations, in spite of the alleged inability of numerical techniques to do so. In one case (Leptopelis), the resulting phenogram suggests a polyphyletic adaptation to burrowing habits, which is in agreement with the shrinking and fading out of many scattered forest remnants during the arid phases of the recent climatic cycles. © 1981 Taylor & Francis Group, LLC.