The Evolutionary Origins of the Southern Ocean Philobryid Bivalves: Hidden Biodiversity, Ancient Persistence
The Evolutionary Origins of the Southern Ocean Philobryid Bivalves: Hidden Biodiversity, Ancient Persistence
复制标题
南大洋双壳类的进化起源：隐藏的生物多样性，古老的持久性
作者：
J. Jackson;K. Linse;R. Whittle;H. Griffiths
Philobryids（双壳类：Arcoida）是南大洋最具物种多样性的海洋双壳类之一，在整个南半球都很常见。考虑到这种多样性和它们的育雏繁殖模式（限制长距离扩散），这个家庭可能已经存在于南大洋自成立以来。然而，Philobrya和Adacnarca只出现在南极洲的第四纪化石记录中，这表明它们的入侵时间要晚得多。分子测年提供了一种独立的方法来测量这个鲜为人知的群体的起源和辐射时间。在这里，我们提出了第一个相结合的分子和形态学调查的Philobryidae在南大洋。从35个南大洋Adacnarca和Philobrya样本中扩增了2个核基因座（18S和28S），总序列长度为2，282 bp。Adacnarca标本（A. nitens和A. limopsoides）作为一个强有力的支持单系群。Philobrya属分为两个强有力的支持组（'sublaevis'和'magellanica/wandelensis'），与Adacnarca并系。助理通过分类群的形态学和遗传学分析，确定nitens种复合体至少有7个形态种。系统发育分析解决Philobryidae作为一个强有力的支持单系分支和姐妹分类单元的Limopsidae，预期他们的分类到超家庭Limopsoidea。贝叶斯松弛时钟分析的分歧时间表明，属Adacnarca辐射在南大洋从古近纪早期，而P. sublaevis和P. wandelensis分支辐射在中新世晚期，随着南极绕极流的形成。
Philobryids (Bivalvia: Arcoida) are one of the most speciose marine bivalve families in the Southern Ocean and are common throughout the Southern Hemisphere. Considering this diversity and their brooding reproductive mode (limiting long-distance dispersal), this family may have been present in the Southern Ocean since its inception. However Philobrya and Adacnarca appear only in the Quaternary fossil record of the Antarctic, suggesting a much more recent incursion. Molecular dating provides an independent means of measuring the time of origin and radiation of this poorly known group. Here we present the first combined molecular and morphological investigation of the Philobryidae in the Southern Ocean. Two nuclear loci (18S and 28S) were amplified from 35 Southern Ocean Adacnarca and Philobrya specimens, with a combined sequence length of 2,282 base pairs (bp). Adacnarca specimens (A. nitens and A. limopsoides) were resolved as a strongly supported monophyletic group. Genus Philobrya fell into two strongly supported groups (‘sublaevis’ and ‘magellanica/wandelensis’), paraphyletic with Adacnarca. The A. nitens species complex is identified as at least seven morpho-species through morphological and genetic analysis of taxon clustering. Phylogenetic analyses resolve Philobryidae as a strongly supported monophyletic clade and sister taxon to the Limopsidae, as anticipated by their classification into the superfamily Limopsoidea. Bayesian relaxed clock analyses of divergence times suggest that genus Adacnarca radiated in the Southern Ocean from the Early Paleogene, while P. sublaevis and P. wandelensis clades radiated in the late Miocene, following the formation of the Antarctic Circumpolar Current.
影响因子：
10.7
作者：
Baele, Guy;Lemey, Philippe;Alekseyenko, Alexander V.
通讯作者：
Alekseyenko, Alexander V.
影响因子：
10.7
作者：
Baele, Guy;Li, Wai Lok Sibon;Lemey, Philippe
通讯作者：
Lemey, Philippe