Maddison Wayne
Department of Zoology, University of California, Berkeley CA 94720, U.S.A.
Cladistics. 1989 Dec;5(4):365-377. doi: 10.1111/j.1096-0031.1989.tb00569.x.
Abstract- Algorithms to reconstruct character evolution on polytomous cladograms or phylogenetic trees have to date interpreted each polytomy literally, as if it were an event of multiple speciation, with multiple daughter species descending independently from a mother species, thus requiring any similarities shared by only some of these daughters to be accounted for by convergence. These algorithms are not appropriate when the polytomy is interpreted in the usual way, namely as representing uncertainty in the cladogram's resolution. New algorithms for both ordered and unordered characters are presented to reconstruct character evolution under the uncertain-resolution interpretation of polytomies. These algorithms allow the cladogram to resolve itself so as to be favourable for the character whose evolution is being reconstructed. Because different characters may have different favourable resolutions, it is not possible in general to use these algorithms to determine the total parsimony of a polytomous cladogram (the number of evolutionary steps required over all characters by the cladogram), for which the only adequate approach is to find a most parsimonious dichotomous resolution of the cladogram.
摘要——迄今为止，用于在多歧分支图或系统发育树上重建性状演化的算法都是按字面意思解释每一个多歧分支，就好像它是一个多次物种形成事件，多个子代物种从一个母物种独立演化而来，因此要求只有部分子代共享的任何相似性都要通过趋同来解释。当多歧分支按通常方式解释时，即表示分支图分辨率的不确定性时，这些算法并不适用。本文提出了用于有序和无序性状的新算法，以在多歧分支的不确定分辨率解释下重建性状演化。这些算法允许分支图自行解析，从而有利于正在重建其演化的性状。由于不同性状可能有不同的有利分辨率，一般不可能用这些算法来确定多歧分支图的总简约性（分支图对所有性状所需的演化步骤数），对于这一点，唯一合适的方法是找到分支图的最简约二叉分辨率。
