RESUMEN
Recent data accumulated from fields as varied as avian palaeontology, palaeobotany, historical biogeography and molecular phylogenetics provide a completely renewed picture of the origin, evolution and distribution of modern birds. Although the origin of birds is still controversial, their Tertiary history is now well known. The reconstruction of palaeoenvironments and the identification of shifts in major vegetation belts and habitats during the Pliocene-Pleistocene epochs have added to these recent developments. Together they provide a new perspective on speciation and extinction rates since the late Pliocene and the establishment of modern avifaunas in the western Palaearctic.
RESUMEN
Two groups of flightless ratite birds existed in New Zealand during the Pleistocene: the kiwis and the moas. The latter are now extinct but formerly included 11 species. We have enzymatically amplified and sequenced approximately 400 base pairs of the mitochondrial 12S rRNA gene from bones and soft tissue remains of four species of moas as well as eight other species of ratite birds and a tinamou. Contrary to expectation, the phylogenetic analysis shows that the kiwis are more closely related to Australian and African ratities than to the moas. Thus, New Zealand probably was colonized twice by ancestors of ratite birds.
