Am J Bot. 1997 Apr;84(4):565.
Apiaceae and Araliaceae (Apiales) represent a particularly troublesome example of the difficulty in understanding evolutionary relationships between tropical-temperate family pairs. Previous studies based on rbcL sequence data provided insights at higher levels, but were unable to resolve fully the family-pair relationship. In this study, sequence data from a more rapidly evolving gene, matK, was employed to provide greater resolution. In Apiales, matK sequences evolve an average of about two times faster than rbcL sequences. Results of phylogenetic analysis of matK sequences were first compared to those obtained previously from rbcL data; the two data sets were then combined and analyzed together. Molecular analyses confirm the polyphyly of apiaceous subfamily Hydrocotyloideae and suggest that some members of this subfamily are more closely related to Araliaceae than to other Apiaceae. The remainder of Apiaceae forms a monophyletic group with well-defined subclades corresponding to subfamilies Apioideae and Saniculoideae. Both the matK and the combined rbcL-matK analyses suggest that most Araliaceae form a monophyletic group, including all araliads sampled except Delarbrea and Mackinlaya. The unusual combination of morphological characters found in these two genera and the distribution of matK and rbcL indels suggest that these taxa may be the remnants of an ancient group of pro-araliads that gave rise to both Apiaceae and Araliaceae. Molecular data indicate that the evolutionary history of the two families is more complex than simple derivation of Apiaceae from within Araliaceae. Rather, the present study suggests that there are two well-defined "families," both of which may have been derived from a lineage (or lineages) or pro-araliads that may still have extant taxa.
伞形科和五加科（伞形目）是理解热带温带科对间进化关系的特别棘手的例子。以前基于 rbcL 序列数据的研究提供了在更高水平上的见解，但未能完全解决科对关系。在本研究中，采用了一个进化更快的基因 matK 的序列数据，以提供更高的分辨率。在伞形目中，matK 序列的进化速度比 rbcL 序列平均快约两倍。matK 序列的系统发育分析结果首先与以前基于 rbcL 数据获得的结果进行比较；然后将这两个数据集组合并一起进行分析。分子分析证实了伞形科 Hydrocotyloideae 亚科的多系性，并表明该亚科的一些成员与五加科的关系比与其他伞形科的关系更密切。伞形科的其余部分与 Apioideae 和 Saniculoideae 亚科形成一个单系群，并有明确的亚分支。matK 和联合 rbcL-matK 分析都表明，大多数五加科形成一个单系群，包括除了 Delarbrea 和 Mackinlaya 之外采样的所有 araliads。这两个属中发现的形态特征的不寻常组合以及 matK 和 rbcL 插入缺失的分布表明，这些分类群可能是古老的 pro-araliads 群的残余，这些群起源于伞形科和五加科。分子数据表明，这两个科的进化历史比简单地从五加科中衍生出伞形科更为复杂。相反，本研究表明，有两个定义明确的“科”，它们都可能是从一个或多个 pro-araliads 谱系衍生而来，这些谱系可能仍有现存的分类群。
