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31.
Phylogenetic relationships and rates of allozyme evolution among the lineages of sceloporine sand lizards 总被引:1,自引:0,他引:1
KEVIN DE QUEIROZ 《Biological journal of the Linnean Society. Linnean Society of London》1992,45(4):333-362
Parsimony analysis of characters derived from an electrophoretic survey of allozyme variation in the sceloporine sand lizards indicates that Uma is outside of a clade formed by the rest of the sand lizards and that Cophosaurus and Holbrookia share a more recent common ancestor with one another than either does with Callisaurus. Previous electrophoretic studies used phenetic clustering based on genetic distance data to assess relationships among these taxa. The resulting dendrograms were used to argue that Holbrookia is the sister group of all other sand lizards and that Callisaurus and Cophosaurus are sister taxa. When reanalysed using parsimony methods, the data from these previous studies are found to support the conclusions of the present study, namely, that Uma rather than Holbrookia is the sister group of all other sand lizards and that Cophosaurus is the sister taxon of Holbrookia rather than of Callisaurus. Relative rate tests indicate that the incongruencies between branching diagrams derived from phenetic clustering of genetic distances versus those derived from parsimony analysis of electrophoretic characters are attributable to increased rates of protein evolution in the Holbrookia lineage. 相似文献
32.
The preparation of 24-nor-5β-chol-22-enes from formyloxy-5β-cholanic acids by oxidative decarboxylation with lead tetraacetate is described. NMR data is presented with other physical constants for the norcholenes derived from cholic, chenodeoxycholic, ursodeoxycholic, hyodeoxycholic, and deoxycholic acids. The facile synthesis of these norcholenes demonstrates the applicability of the formyloxy protecting group to oxidative decarboxylations in the bile acid series. 相似文献