02060nas a2200145   4500008004100000245008400041210006900125260000900194300001200203490000700215520156700222100002401789700002501813856007601838       1998                        eng d00aMorphological correlations in evolution: Consequences for phylogenetic analysis0 aMorphological correlations in evolution Consequences for phyloge  cJune  a141-1620 v733 aMethods of inferring phylogenetic relationships have received an enormous amount of attention in recent years. One missing component in much of this work concerns the analysis of the data being used. Most techniques of phylogenetic inference, including parsimony, assume the independence of characters, and the assignment of equal weights to characters assumes that they have an equal probability of change. Although systematists using molecular data have begun to deal with issues of character correlation and weighting, they are generally avoided by those using morphological data. Systematists have paid relatively little attention to morphological characters that may be correlated for reasons other than commonality of descent. We review some of the reasons that the assumption of independence of characters may be violated for morphological features, and suggest ways in which detailed analysis of the phenotype may lead to both a priori and a posteriori rationales for weighting of morphological characters. Just as it seems prudent to explore phylogenetic hypotheses that are less than the most parsimonious, systematics would be well served if researchers more fully explored the causes and consequences of character correlations that may exist in morphological data sets. Our two examples, the evolution of sexual dimorphism in voiceless frogs and the role of heterochrony in the evolution of chaenopsid fishes, illustrate that character weighting provides potential insights into both systematic relationships and the evolution of character complexes.1 aEmerson, Sharon, B.1 aHastings, Philip, A.  ufile://localhost/Users/breda/Desktop/Documents/Literature/E/Emerson.pdf01482nas a2200169   4500008004100000245004800041210004800089260000800137300001000145490000800155520101700163653002001180653001301200100002101213700002401234856005401258       2003                        eng d00aParallelism and convergence in anuran fangs0 aParallelism and convergence in anuran fangs  cMay  a41-510 v2603 aThe anuran lower jaw is composed of three pairs of bones: dentaries, angulosplenials and mentomeckelians. Although the lower jaw is toothless, except in Gastrotheca guentheri, enlarged fangs or odontoids have evolved at least four times independently in some myobatrachids, hylids, ranids and leptodactylids through both parallel and convergent evolutionary events. Fangs seem to represent the single best design solution to enable an anuran to inflict a bite-like wound, but the biological role of biting varies among species. Fangs are projections of the dentaries in ranids, but in the hylid frog Hemiphractus and in ceratophryine leptodactylids, they form a sinosteotic unit with the dentaries and mentomeckelians. Comparisons of morphology, behaviour and diet among frog taxa with enlarged fangs reveal that the fangs may be the result of either sexual or natural selection. Those fangs that evolved in response to sexual selection seem to be relatively larger than those that resulted of natural selection.10aDimorphognathus10aodotoids1 aFabrezi, Marissa1 aEmerson, Sharon, B.  uhttps://africanamphibians.myspecies.info/node/321