Data from: The phylogeny and biogeography of Hakea (Proteaceae) reveals the role of biome shifts in a continental plant radiation

The frequency of evolutionary biome shifts during diversification has important implications for our ability to explain geographic patterns of plant diversity. Recent studies present several examples of biome shifts, but whether frequencies of biome shifts closely reflect geographic proximity or environmental similarity of biomes remains poorly known. We explore this question by using phylogenomic methods to estimate the phylogeny of Hakea, a diverse Australian genus occupying a wide range of biomes. Model-based estimation of ancestral regions indicates that Hakea began diversifying in the Mediterranean biome of southern Australia in the Middle Eocene – Early Oligocene, and dispersed repeatedly into other biomes across the continent. We infer around 47 shifts between biomes. Frequencies of shifts between pairs of biomes are usually similar to those expected from their geographic connectedness or climatic similarity, but in some cases are substantially higher or lower than expected, perhaps reflecting how readily key physiological traits can be modified to adapt lineages to new environments. The history of frequent biome-shifting is reflected in the structure of present-day assemblages, which tend to be more phylogenetically diverse than null-model expectations. The case of Hakea demonstrates that the radiation of large plant clades across wide geographic areas need not be constrained by dispersal limitation or conserved adaptations to particular environments.演化辐射过程中生物群系（biome）转移的频率，对阐释植物多样性的地理分布格局具有重要理论意义。现有研究已报道多例生物群系转移事件，但生物群系转移频率是否与生物群系间的地理邻近性、环境相似性紧密相关，目前仍未得到明确解答。我们以澳大利亚地域分布广泛、物种多样性丰富的哈克木属（Hakea）为研究类群，借助系统发育组学方法重建其系统发育关系，以此探讨这一科学问题。基于模型的祖先分布区重建结果显示，哈克木属于中始新世-早渐新世在澳大利亚南部的地中海型生物群系中起始辐射演化，并多次扩散至澳洲大陆的其他生物群系。经推断，该属共发生约47次生物群系转移事件。成对生物群系间的转移频率，通常与其地理连通性或气候相似性的理论预期值相符，但部分类群的转移频率显著高于或低于预期水平，这可能反映了关键生理性状的改造难易程度，决定了演化支系适应新环境的潜力。频繁的生物群系转移历史，同样体现在现存植物群落的结构特征中：相较于零模型（null model）的预期结果，这些群落往往呈现出更高的系统发育多样性。哈克木属的研究案例表明，大型植物支系在广阔地理范围内的辐射演化，未必受限于扩散限制或对特定环境的保守适应性。