Lalueza-Fox Carles, Shapiro Beth, Bover Pere, Alcover Josep Antoni, Bertranpetit Jaume
Laboratori d'Antropologia, Facultat de Biologia, Universitat de Barcelona, Avda. Diagonal 645, Spain.
Mol Phylogenet Evol. 2002 Dec;25(3):501-10. doi: 10.1016/s1055-7903(02)00290-7.
Myotragus balearicus was a dwarf artiodactyl endemic to the Eastern Balearic Islands, where it evolved in isolation for more than 5 million years before becoming extinct between 3640 and 2135 cal BC (calibrated years BC). Numerous unusual apomorphies obscure the relationship between Myotragus and the extant Caprinae. Therefore, genetic data for this species would significantly contribute to the clarification of its taxonomic position. In this study, we amplify, sequence, and clone a 338-base pair (bp) segment of the mitochondrial cytochrome b (cyt b) gene from a >9Kyr Myotragus subfossil from la Cova des Gorgs (Mallorca). Our results confirm the phylogenetic affinity of Myotragus with the sheep (Ovis) and the takin (Budorcas). In each tree, the Myotragus branch is long in comparison with the other taxa, which may be evidence of a local change in the rate of evolution in cyt b. This rate change may be due to in part to an early age of first reproduction and short generation time in Myotragus, factors that are potentially related to the extreme reduction in size of the adult Myotragus as compared to the other Caprinae.
巴氏野猪是一种侏儒偶蹄动物，原产于东巴利阿里群岛，在那里它孤立进化了500多万年，于公元前3640年至2135年（校准后的公元前年份）灭绝。众多不寻常的衍征模糊了巴氏野猪与现存山羊亚科之间的关系。因此，该物种的基因数据将极大地有助于澄清其分类地位。在本研究中，我们从来自拉科瓦德戈尔格斯（马略卡岛）的一具距今超9000年的巴氏野猪亚化石中扩增、测序并克隆了线粒体细胞色素b（cyt b）基因的一段338个碱基对（bp）的片段。我们的结果证实了巴氏野猪与绵羊（盘羊属）和羚牛之间的系统发育亲缘关系。在每棵树中，巴氏野猪的分支与其他分类群相比都很长，这可能是细胞色素b进化速率发生局部变化的证据。这种速率变化可能部分归因于巴氏野猪首次繁殖的年龄较早和世代时间较短，这些因素可能与成年巴氏野猪相对于其他山羊亚科动物体型极度缩小有关。
