With the realization that much of the biological diversity on Earth has been generated by discrete evolutionary radiations, there has been a rapid increase in research into the biotic (key innovations) and abiotic (key environments) circumstances in which such radiations took place. Here we focus on the potential importance of population genetic structure and trait genetic architecture in explaining radiations. We propose a verbal model describing the stages of an evolutionary radiation: first invading a suitable adaptive zone and expanding both spatially and ecologically through this zone; secondly, diverging genetically into numerous distinct populations; and, finally, speciating. There are numerous examples of the first stage; the difficulty, however, is explaining how genetic diversification can take place from the establishment of a, presumably, genetically depauperate population in a new adaptive zone. We explore the potential roles of epigenetics and transposable elements (TEs), of neutral process such as genetic drift in combination with trait genetic architecture, of gene flow limitation through isolation by distance (IBD), isolation by ecology and isolation by colonization, the possible role of intra‐specific competition, and that of admixture and hybridization in increasing the genetic diversity of the founding populations. We show that many of the predictions of this model are corroborated. Most radiations occur in complex adaptive zones, which facilitate the establishment of many small populations exposed to genetic drift and divergent selection. We also show that many radiations (especially those resulting from long‐distance dispersal) were established by polyploid lineages, and that many radiating lineages have small genome sizes. However, there are several other predictions which are not (yet) possible to test: that epigenetics has played a role in radiations, that radiations occur more frequently in clades with small gene flow distances, or that the ancestors of radiations had large fundamental niches. At least some of these may be testable in the future as more genome and epigenome data become available. The implication of this model is that many radiations may be hard polytomies because the genetic divergence leading to speciation happens within a very short time, and that the divergence history may be further obscured by hybridization. Furthermore, it suggests that only lineages with the appropriate genetic architecture will be able to radiate, and that such a radiation will happen in a meta‐population environment. Understanding the genetic architecture of a lineage may be an essential part of accounting for why some lineages radiate, and some do not.

中文翻译：

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进化辐射的遗传学

认识到地球上的大部分生物多样性是由离散的进化辐射产生的，对发生这种辐射的生物（关键创新）和非生物（关键环境）环境的研究迅速增加。在这里，我们关注种群遗传结构和性状遗传结构在解释辐射方面的潜在重要性。我们提出了一个描述进化辐射阶段的语言模型：首先侵入一个合适的适应区域，并通过该区域在空间和生态上扩展；其次，从基因上分化为许多不同的种群；最后，规范。第一阶段的例子很多；然而，困难在于解释如何从建立一个，据推测，在一个新的适应区中遗传贫乏的种群。我们探索了表观遗传学和转座因子 (TE)、遗传漂变与性状遗传结构相结合的中性过程、通过距离隔离 (IBD)、生态隔离和定植隔离限制基因流动的潜在作用，可能的种内竞争以及混合和杂交在增加创始种群遗传多样性方面的作用。我们表明该模型的许多预测都得到了证实。大多数辐射发生在复杂的适应区，这有助于建立许多暴露于遗传漂变和不同选择的小种群。我们还表明，许多辐射（尤其是那些由远距离传播引起的辐射）是由多倍体谱系建立的，并且许多辐射谱系的基因组大小很小。然而，还有其他一些预测（尚）无法验证：表观遗传学在辐射中发挥了作用，辐射在基因流距离小的进化枝中更频繁地发生，或者辐射的祖先具有大的基本生态位。随着更多基因组和表观基因组数据的可用，至少其中一些可能在未来进行测试。这个模型的含义是，许多辐射可能是硬多分体，因为导致物种形成的遗传分歧发生在很短的时间内，而且分歧的历史可能会被杂交进一步掩盖。此外，这表明只有具有适当遗传结构的谱系才能辐射，并且这种辐射将发生在元种群环境中。了解谱系的遗传结构可能是解释为什么有些谱系会辐射而有些不会辐射的重要部分。