Dodd Michael E, Silvertown Jonathan, Chase Mark W
Ecology and Conservation Research Group, Biology Department, Open University, Milton Keynes, MK7 6AA, United Kingdom.
Royal Botanic Gardens, Kew, Richmond, Surrey, TW9 3DS, United Kingdom.
Evolution. 1999 Jun;53(3):732-744. doi: 10.1111/j.1558-5646.1999.tb05367.x.
Angiosperm families differ greatly from one another in species richness (S). Previous studies have attributed significant components of this variation to the influence of pollination mode (biotic/abiotic) and growth form (herbaceous/woody) on speciation rate, but these results suffer difficulties of interpretation because all the studies ignored the phylogenetic relationships among families. We use a molecular phylogeny of the angiosperm families to reanalyse correlations between S and family-level traits and use reconstructions of trait evolution to interpret the results. We confirm that pollination mode and growth form are correlated with S and show that the majority of changes in pollination mode involved a change from biotic to abiotic pollination with an associated fall in speciation rate. The majority of growth form changes involved the evolution of herbaceousness from woodiness with a correlated rise in speciation rate. We test the hypothesis of Ricklefs and Renner (1994) that "evolutionary flexibility" rather than other trait changes triggered increased speciation rates in some families, but find little support for the hypothesis.
被子植物科在物种丰富度（S）上彼此差异很大。先前的研究将这种变异的重要组成部分归因于授粉方式（生物/非生物）和生长形式（草本/木本）对物种形成速率的影响，但这些结果在解释上存在困难，因为所有研究都忽略了科之间的系统发育关系。我们利用被子植物科的分子系统发育来重新分析物种丰富度与科级性状之间的相关性，并利用性状进化重建来解释结果。我们证实授粉方式和生长形式与物种丰富度相关，并表明授粉方式的大多数变化涉及从生物授粉到非生物授粉的转变，同时物种形成速率随之下降。生长形式的大多数变化涉及从木本到草本的进化，同时物种形成速率相应上升。我们检验了里克利斯和伦纳（1994年）的假设，即“进化灵活性”而非其他性状变化在一些科中引发了物种形成速率的增加，但几乎没有找到支持这一假设的证据。
