The taxonomist then uses DNA sequence attributes to test the morphological hypothesis of aggregation and corroborates the morphological hypothesis and the taxonomist ‘breaks out’ of the circle. When geographical distributions are used to test the aggregation patterns, there is no geographic pattern to the distribution of the different morphological types. A hypothesis of aggregation is posited based on the morphological information. Sympatric species in taxonomy morphological differences are recognized among a group of organisms.
Retaining the geographical hypothesis the taxonomist then examines the aggregates established using the geographical hypothesis with DNA sequence data and corroboration ensues with DNA sequence characters being diagnostic. The morphological attributes collected do not corroborate the geographical hypothesis and hence the taxonomist cannot ‘break out’ of the circle. Cryptic species in taxonomy a geographical hypothesis is posed and tested with morphology. The morphological attributes then become diagnostic characters if they corroborate the geographical hypothesis. The taxonomic hypothesis is tested with morphological information and corroborated with the morphological attributes. Classical morphological taxonomy a taxonomic hypothesis is established on the basis of organisms appearing to be similar at a particular geographic locality. Examples of use of the taxonomic circle using hypothetical examples. In our scheme, it only takes one traversal of the interior of the taxonomic circle where corroboration occurs in order for the taxonomist to ‘break out’ of the circle and designate a taxon. The only way to delineate a new taxon is to break out of the circle (the solid arrows emanating from the circle). The dotted lines that traverse the inner part of the circle indicate experimental routes that can be taken in taxonomic endeavour to accomplish corroboration of taxonomic hypotheses. The top population is diagnosed by GA, AG/GA, AG for the four columns. Yet in combination the four columns provide a diagnostic system for the top population versus the bottom. The four columns marked by the shading for D are neither diagnostic nor private. However, in combination these two columns provide a ‘pure’ diagnostic combination (AA versus AG or GA ‘compound pure’ character in the terminology of Sarkar et al. The DNA sequence attributes in the two columns by themselves constitute two private DNA positions.
DNA sequence attributes in this column are not purely diagnostic, but rather the G in the three individuals in the top population are ‘private’ to that population. DNA sequence attributes in these columns are purely diagnostic characters (sensu Davis & Nixon 1992). The solid line through the middle of the matrix represents a geographical barrier between the two populations. The twelve sequences represent two populations of six individuals each. Hypothetical example of character based diagnosis (Davis & Nixon 1992) in action. In this paper we discuss these two concerns generated around the DNA barcoding initiative and attempt to present a phylogenetic systematic framework for an improved barcoder as well as a taxonomic framework for interweaving classical taxonomy with the goals of 'DNA barcoding'. Our preference is for the title of the London meetings-Barcoding Life. In fact, we feel that DNA barcoding is a misnomer. This issue is extremely important in that the classical taxonomic approach and the DNA approach will need to be reconciled in order for the 'DNA barcoding' initiative to proceed with any kind of community acceptance. The second problem involves the reaction of the taxonomic community to the directives of the 'DNA barcoding' initiative. Currently, many of the published studies under this initiative have used tree building methods and more precisely distance approaches to the construction of the trees that are used to place certain DNA sequences into a taxonomic context. The first issue concerns how DNA data are to be used in the context of this initiative this is the DNA barcode reader problem (or barcoder problem). It is critical that these two issues are clarified and resolved, before the use of DNA as a tool for taxonomy and species delimitation can be universalized. Recent excitement over the development of an initiative to generate DNA sequences for all named species on the planet has in our opinion generated two major areas of contention as to how this 'DNA barcoding' initiative should proceed.
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