Data from: The shape of modern tree reconstruction methods

One characteristic of inferred phylogenetic trees is their shape. Rooted binary trees are more balanced, or symmetric, to the extent that sister groups contain similar number of leaves. Premised on the idea that macroevolutionary processes may leave a strong signature in the shape of phylogenetic trees, inferred tree shapes can be compared to expectations under probabilistic models of speciation and extinction in an attempt to make macroevolutionary inferences (e.g. Harvey and Purvis, 1991; Kirpatrick and Slatkin, 1993; Guyer and Slowinski, 1993; Mooers and Heard, 1997; Bortolussi et al., 2006).推断获得的系统发育树（phylogenetic tree）具有独特的形态特征。有根二叉树（rooted binary tree）的平衡性与对称性更强，具体表现为其姊妹群（sister group）所包含的叶节点数量相近。基于“宏进化过程可在系统发育树的形态上留下显著印记”这一核心前提，可将推断得到的树形态与物种形成与灭绝概率模型下的预期形态进行比对，以此开展宏进化推断（例如Harvey和Purvis，1991；Kirpatrick和Slatkin，1993；Guyer和Slowinski，1993；Mooers和Heard，1997；Bortolussi et al.，2006）。