Taxonomic correlations

All such characteristics may be useful and, along with the morphological features, may facilitate taxonomic correlation of the Lactarius species. 

For the reliable application of taxonomic correlations, therefore, the same conceptions about the compounds potential modes of action are required, as for QSARs. Subjected to similar limitations, QSARs and interspecies correlations use similar principles and methods and may complement each other when used to obtain toxicity estimates if experimental results are unavailable. 

In a study comparing nine moth species, Steinbrecht (1996) observed that cross-reactivity of specific antisera to one species with PBPs from another species was not correlated with taxonomic relatedness of the species, but rather with the pheromone chemistry. Given that the highly divergent specificity of pheromone receptor cells in the Noctuidae species studied appears to be mirrored by a similar diversity of PBP sequences in sensilla trichodea, Steinbrecht suggested that PBPs participate in odorant discrimination (Steinbrecht, 1996). 

It is doubtful that the data available justify quite such a sweeping statement. First, although the physiological functions of many compounds they mention are indeed unknown, it may not be fair to take them out of the context of metabolic pathways. They may be intermediates in the synthesis of pigments, hormones, or other compounds of known function. Conflicting reports on their rate of turnover exist. Second, the reviewers did not correlate plant chemistry specifically with feeding preference they simply assumed that taxonomically (basically that means morphologically) related plants would be similar in their chemical composition. In a very simple, direct way, the work of Brower (below) indicates that this assumption cannot be made. Third, we still need more cause-and-effect evidence for the relationship between plant... 

In addition, elementary analytics as broad-scoped as this allows for comparisons of metal concentrations beyond taxonomic borders as well as those of spatial, bioclimatic distributions. These comparisons eventually (1989) were merged into a complete set of abundance correlations among 45 chemical elements (including non-metals like B, Si, Cl or Br) for 13 plant species or parts thereof. Markert called this set of abundance correlations the Biological System of Elements (BSE, Fig. 1.3). 

The polar lipid composition of extreme halophiles appears to be correlated with their taxonomic classification on the level of the genera so far distinguished [4,5,10,32, 50-52,54] Halobacterium, Haloarcula, Haloferax, Halococcus, Natronobacterium and Natronococcus (Table 1). All of these genera were found to contain C2o-C2o-archaeol PGP-Me (4A) as the major phospholipid, C2o-C2o-archaeol PG (3) and PGS (5) as minor phospholipids, and small to trace amounts of archaeol PA (6) [5,10,11,32,40] (see Table 1), with the following exceptions (a) PGS is characteristically absent... 

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