Morphology, Development, and Sequence

An arthropod phylogeny derived from nucleotide sequences (Regier et al., 2010) did not consider either the morphology or the development of crustaceans. Examples of a morphological transformation and developmental data appear to provide only limited support for the cladogram because similar morphology and development are found among distantly related crustaceans, while differing morphology and development are found among closely related crustaceans. One reason for the incongruity may be a method of sequence analysis that results in statistical support values. This method samples a population of purposefully-generated cladograms, although there has been only one history of life on earth; in effect the purposefully-generated cladograms are instrumental artifacts.