Ochotona princeps (pika) myoglobin: an appraisal of lagomorph phylogeny.

Myoglobin was purified from skeletal muscle of the pika (Ochotona princeps) and its primary structure was determined. This sequence was added to the set of 64 already known vertebrate myoglobin sequences and used to evaluate the phylogenetic position of the pika among other mammals, using a computerized search procedure based on maximum parsimony criteria. The pika is clearly related to the rabbit (Oryctolagus cuniculus), with which it is traditionally associated as a member of the order Lagomorpha. A monophyletic group composed of Lagomorpha, Scandentia, and Carnivora is a consistent feature of the dendrograms produced. An association of Carnivora and Lagomorpha casts doubt on the results of those investigations using rabbit antisera in systematic studies and depending on carnivores as an outside reference group for cladogram construction.