Data from: Parallel polyploid speciation: distinct sympatric gene-pools of recurrently derived allo-octoploid Asplenium ferns

Although polyploidy is widespread, its significance to the generation of biodiversity remains unclear. Many polyploids have been derived recurrently. For a particular polyploid, gene-flow between the products of independent origin is typical where they come into contact. Here, we use AFLP DNA-fingerprinting and chloroplast DNA sequences to demonstrate parallel polyploid speciation within both of the ferns Asplenium cimmeriorum and A. gracillimum. Both of these taxa comprise at least two allopolyploids, recurrently derived from the same progenitor pair. Each of these allopolyploids remain genetically distinguishable even with extensive sympatry, and could therefore be considered distinct species. To our knowledge, parallel speciation on this scale amongst recurrent polyploids has not been previously reported. With their parallel origins, these 'evolutionary replicates' provide an unrivalled opportunity to investigate how the reproductive barriers and ecological differentiation necessary for speciation arise following polyploidy.

尽管多倍性（polyploidy）现象广泛分布于各类生物类群中，但其对生物多样性形成的重要意义仍未明确。诸多多倍体类群均经重复起源事件形成。对于某一特定多倍体而言，当其独立起源的不同子代类群发生接触时，彼此间的基因流（gene-flow）实为普遍现象。本研究通过扩增片段长度多态性（AFLP）DNA指纹图谱与叶绿体DNA序列分析，证实了蕨类铁角蕨属（Asplenium）的两个物种——A. cimmeriorum与A. gracillimum中均存在平行多倍体物种形成现象。这两个类群均包含至少两种异源多倍体（allopolyploids），且均由同一套亲本组合经重复起源产生。即便这些异源多倍体存在广泛的同域分布（sympatry），彼此间仍可通过遗传特征相互区分，因此可被认定为独立物种。据我们所知，此前尚未有关于重复起源多倍体发生如此大规模平行物种形成的相关报道。凭借其平行起源的特性，这些‘进化重复体’为探究多倍化后，物种形成所需的生殖隔离与生态分化如何得以形成，提供了无与伦比的研究契机。