Data from: Convergent and correlated evolution of major life-history traits in the angiosperm genus Leucadendron (Proteaceae)

Natural selection is expected to cause convergence of life histories among taxa as well as correlated evolution of different life-history traits. Here, we quantify the extent of convergence of five key life-history traits (adult fire survival, seed storage, degree of sexual dimorphism, pollination mode, and seed-dispersal mode) and test hypotheses about their correlated evolution in the genus Leucadendron (Proteaceae) from the fire-prone South African fynbos. We reconstructed a new molecular phylogeny of this highly diverse genus that involves more taxa and molecular markers than previously. This reconstruction identifies new clades that were not detected by previous molecular study and morphological classifications. Using this new phylogeny and robust methods that account for phylogenetic uncertainty, we show that the five life-history traits studied were labile during the evolutionary history of the genus. This diversity allowed us to tackle major questions about the correlated evolution of life-history strategies. We found that species with longer seed-dispersal distances tended to evolve lower pollen-dispersal distance, that insect-pollinated species evolved decreased sexual dimorphism, and that species with a persistent soil seed-bank evolved toward reduced fire-survival ability of adults.

自然选择被推测可引发类群（taxa）间生活史的趋同演化，以及不同生活史性状的协同进化。本研究针对源自易发生火灾的南非凡波斯植被（fynbos）区的山龙眼科（Proteaceae）银叶树属（Leucadendron）类群，首先量化了5个关键生活史性状——成体火灾存活率、种子贮藏特性、性二态性程度、传粉模式与种子传播模式——的趋同程度，随后检验了关于这些性状协同演化的相关假说。我们构建了该高度多样属的全新分子系统发育树，其涵盖的类群与分子标记数量均优于既往研究；本次系统发育重建还识别出了既往分子研究与形态分类均未发现的新演化支（clade）。依托该全新系统发育树与考虑系统发育不确定性的稳健分析方法，我们证实在所研究属的演化历程中，这5个生活史性状均具有较高的演化可塑性。这种性状多样性为我们解答生活史策略协同演化的核心问题提供了契机。研究结果显示：种子传播距离更长的类群，其花粉传播距离往往更短；以昆虫为传粉媒介的类群，其性二态性程度会降低；拥有持久土壤种子库的类群，其成体火灾存活率则呈现下降的演化趋势。