Griffith School of Environment and School of Biomolecular and Physical Sciences, Griffith University, Nathan, Australia.
PLoS One. 2011 Apr 11;6(4):e18728. doi: 10.1371/journal.pone.0018728.
The King Island Emu (Dromaius ater) of Australia is one of several extinct emu taxa whose taxonomic relationship to the modern Emu (D. novaehollandiae) is unclear. King Island Emu were mainly distinguished by their much smaller size and a reported darker colour compared to modern Emu.
We investigated the evolutionary relationships between the King Island and modern Emu by the recovery of both nuclear and mitochondrial DNA sequences from sub-fossil remains. The complete mitochondrial control (1,094 bp) and cytochrome c oxidase subunit I (COI) region (1,544 bp), as well as a region of the melanocortin 1 receptor gene (57 bp) were sequenced using a multiplex PCR approach. The results show that haplotypes for King Island Emu fall within the diversity of modern Emu.
These data show the close relationship of these emu when compared to other congeneric bird species and indicate that the King Island and modern Emu share a recent common ancestor. King Island emu possibly underwent insular dwarfism as a result of phenotypic plasticity. The close relationship between the King Island and the modern Emu suggests it is most appropriate that the former should be considered a subspecies of the latter. Although both taxa show a close genetic relationship they differ drastically in size. This study also suggests that rates of morphological and neutral molecular evolution are decoupled.
澳大利亚的金岛鸸鹋（Dromaius ater）是几种已灭绝的鸸鹋类群之一，其与现代鸸鹋（D. novaehollandiae）的分类关系尚不清楚。金岛鸸鹋主要以体型小得多和据称比现代鸸鹋颜色更深为特征。
我们通过从亚化石遗骸中回收核和线粒体 DNA 序列，研究了金岛鸸鹋与现代鸸鹋之间的进化关系。使用多重 PCR 方法对完整的线粒体控制区（1094 bp）和细胞色素 c 氧化酶亚基 I（COI）区（1544 bp）以及黑素皮质素 1 受体基因的一个区域（57 bp）进行了测序。结果表明，金岛鸸鹋的单倍型存在于现代鸸鹋的多样性中。
与其他同属鸟类相比，这些数据表明这些鸸鹋之间存在密切的关系，并表明金岛鸸鹋和现代鸸鹋具有最近的共同祖先。金岛鸸鹋可能由于表型可塑性而经历了岛屿侏儒化。金岛鸸鹋与现代鸸鹋之间的密切关系表明，将前者视为后者的亚种是最合适的。尽管这两个类群具有密切的遗传关系，但它们在体型上却有很大的差异。本研究还表明形态和中性分子进化的速率是分离的。
