Character analysis

The entire field as indicated above, can be summarized as the character analysis. This analysis, mere or less complete or very onesided, is available for finding an answer to the queation(s) posed. So we return to the two questions, the two challenges, the two commissions of systematica. 

The classification rests on a firmer foundation and can become more robust, when mere characters are involved. However, this does certainly not imply that decisionii are easier then. Sometimes parts of the character analysis do not (seem to) conform. The weighing process becosws more difficult then and often a solution is expected from a broader factual basis including a different Kind of characters, in the hope that the causes of the "conflicting evidence" will become clear and that the conflict will disappear. 

In what way can the phylogenetic history of the group best be reconstructed This question can tn asked for its own scientific value but also in order to use the answer in the classification (see p. 7 under nr. 4). Phylogenetical research can be done on different taxon uni cal levels and with different means. The factual data on which to base the phylogenetical hypothesis are the same as those emerging from the character analysis that is used in classification. 

FIGURE 4.1 Phylogenetic tree based on De Weerdt s [88] morphological character analysis. Black squares represent (syn)apomorphic characters of clades and terminal taxa. The tree is the result of a reanalysis of De Weerdt s data using PAUP 3.1.1 [87] (single most parsimonious tree). The taxon-character matrix is given in Table 4.2. 

TS analysis of inosine arsenolysis. TS analysis was performed on the arsenolysis of inosine under steady state conditions. The primary, KIE was near the lower limit (1.025-1.029) calculated for an AnDn mechanism with adenosine and could indicate either an AnDn or Dn An mechanism. The large a- and j8-secondary KIEs indicated a transition state with high oxocarbenium ion character. Analysis of X-ray crystal structures of PNP demonstrates that there is not enough space in the enzyme active site between the leaving group purine and the phosphate nucleophile to allow formation of a stable oxocarbenium ion (see Section 3). Thus, the most likely mechanism for arsenolysis is an extremely dissociative AnDn mechanism. The primary, 9- N KIE = 1.010 was lower than expected, as discussed below. 

The TS found for the latter mode of addition is very asynchronous with a strong initial interaction of the ketene sp carbon with both carbons of the alkene and considerable polar character. " Analysis of the electronic interactions at the TS by NPA shows substantial charge transfer from ethene to ketene, as would be expected on the... 

KluBmann-Fricke BJ, Prendini L, Wirkner CS. Evolutionary morphology of the hemolymph vascular system in scorpions a character analysis. Arthropod Struct Dev. 2012 pii S1467-8039(12)00056. doi 10.1016/j.asd.2012.06.002. 

Perform a character analysis for the selected similarities. Discover characters of high probability of homology and weigh these higher than those characters of low probability. Characters suspected to evolve easily more than once should be excluded whenever possible or given low weight. 

Describe explicitly all arguments used in the character analysis (steps 2 and 3) and enter the results in a data matrix. 

Therefore, the congruence test does not have the power that Patterson (1982), and other cladists, have claimed for it and cannot replace a priori character analysis. Kluge and Farris (1969), for example, included in their analysis of anuran evolution long paragraphs with a priori character analyses where the selection and quality of characters is discussed. 

There is little point in trying to demonstrate that one or another data set (Recent, fossil or Recent + fossil) yields the best result. Fossils always remain subsidiary to Recent taxa because the identification of primary homology (one of the key stages of what Wagele calls character analysis — [Chapter 5, this volume]) depends on interpreting structures in fossils in the light of those in the Recent world. It is more productive to consider the strengths of... 

Phylogenetic analysis, steps of, 107, 108 Phylogenetic bone fusion, patterns on, 164 Phylogenetic cladistics, 107, 112 Phylogenetics, moleculai 268 Phylogenetic systematics character analysis, 109 logic of, 96... 

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