Albumin Immunologic Relationships of the Macropodidae (Marsupialia)

Abstract

Microcomplement fixation of albumin was used to probe evolutionary relationships among the macropodid marsupials. The data, analyzed by the Fitch-Margoliash method followed by jackknifing, support the recognition of at least three clades; one consists of the macropodine genera Macropus, Wallabia, Setonix, Onychogalea, Dorcopsis, Dorcopsulus, Lagorchestes, Dendrolagus, Petrogale, Peradorcas and Thylogale; a second of the potoroine genera Bettongia, Potorous and Aepyprymnus; and a third of the sthenurine Lagostrophus. Hypsiprymnodon either represents a fourth clade, or is allied with the Bettongia-Potorous-Aepyprymnus clade. Bettongia is a monophyletic genus but the phylogenetic relationships of Bettongia, Potorous and Aepyprymnus are not resolved. There is a strong association of Petrogale, Peradorcus and Thylogale along with, unexpectedly, Dendrolagus. Lagorchestes has no immediate relatives whereas Dorcopsulus and Dorcopsis form a clade. Macropus, Wallabia, Setonix and Onychogalea form a clade, within which Macropus may be paraphyletic. Albumin evolves in a clock-like fashion within the macropodines and within the potoroines but not between macropodines, sthenurines and potoroines. However, it is not possible to calibrate the clock for these groups.