ancestral 专八GRE

The branching points of the cladogram may be regarded either as an ancestral species (as in an evolutionary tree) or solely as representing shared characteristics.

在这个形象化进化树上，每两个物种间距离都是由它们共有特性决定。

The special body plan of Yunnanozoon is almost identical to that of the living enteropneust hemichordate Balanoglossus,which suggests that the earlyCambrian creature is ancestral to the hemichordates.

这种独特身体造型与现生肠索动物几无二致，从而表明这个早寒武世动物是地球上索动物门中已知最古老祖先型。