Captive L. rosalia were observed to exchange food routinely in family groups, a process varying from donation to theft. Donation involved the use of ‘invitational’ signals which operated most efficiently in parent-infant sharing and in donating live prey. Food moved, by sharing and theft, toward: (a) males prior to the female’s first conception; (b) females during late pregnancy; (c) carriers of infants; (d) weanlings; (e) juveniles when infants died; (f) third animals in trios, regardless of their age and relatedness to the pair. Successful reproduction, a complex behavior involving all group members in cooperative infant care and provisioning, is probably enhanced by captive L.rosalia’s food-sharing habits.

Objectives: Documenting the variety of quadrupedal walking gaits in a variety of marsupials (arboreal vs. terrestrial, with and without grasping hind feet), to aid in developing and refining a general theory of gait evolution in primates. Materials and Methods: Video records of koalas, ringtail possums, tree kangaroos, sugar gliders, squirrel gliders, wombats, numbats, quolls, a thylacine, and an opossum walking on a variety of substrates were made and analyzed to derive duty factors and diagonalities for symmetrical walking gaits. The resulting distributions of data points were compared with published data and theories.

Humans are commonly held to be qualitatively different from other animals, especially in their unique mental abilities. Darwinian theory, which provides the only known way of explaining the origin of complex adaptations, assumes that evolution works on quantitative variation within species. It therefore affords no way of explaining qualitative uniqueness. Anthropologists have attributed human uniqueness to cognitive capacity, symbols and language, prosociality, cumulative culture, and complex imitation, and have tried to explain these faculties as the historical products of various combinations of tool use, cooperative hunting and breeding, fire and cooking, and brain enlargement. Because human traits with no nonhuman precursors are not amenable to evolutionary explanation, these debates can be expected to persist so long as anthropology defines itself and its mission in terms of the animal–human boundary.

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