Underpinnings of the distribution of allopolyploid species (hybrids with duplicated genome) along spatial and ecological gradients are elusive. As allopolyploid speciation combines the range of genetic and ecological characteristics of divergent diploids, allopolyploids initially show their additivity and are predicted to evolve differentiated ecological niches to establish in face of their competition. Here, we use four diploid wild wheats that differentially combined into four independent allopolyploid species to test for such additivity and assess the impact of ecological constraints on species ranges. Divergent genetic variation from diploids being fixed in heterozygote allopolyploids supports their genetic additivity. Spatial integration of comparative phylogeography and modelling of climatic niches supports ecological additivity of locally adapted diploid progenitors into allopolyploid species which subsequently colonised wide ranges. Allopolyploids fill suitable range to a larger extent than diploids and conservative evolution following the combination of divergent species appears to support their expansion under environmental changes.

中文翻译：

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异源多倍体野生小麦中二倍体的生态遗传可加性。

沿空间和生态梯度分布的异源多倍体物种（具有重复基因组的杂交体）分布的基础难以捉摸。由于异源多倍体物种形成结合了不同二倍体的遗传和生态特征范围，因此异源多倍体最初显示出它们的可加性，并被预测会进化出不同的生态位，以应对它们的竞争。在这里，我们使用四个二倍体野生小麦，将它们差异组合为四个独立的同种多倍体物种，以测试这种可加性并评估生态约束对物种范围的影响。与固定在杂合子异源多倍体中的二倍体不同的遗传变异支持它们的遗传可加性。比较植物学和气候生态位建模的空间整合支持局部适应二倍体祖先到异源多倍体物种的生态可加性，随后在广泛的范围内定殖。与二倍体相比，同素多倍体在更大的范围内能填充合适的范围，不同物种的结合后的保守进化似乎支持它们在环境变化下的扩展。