According to his analysis of the Bachia family tree, the toed species re-evolved toes from toeless ancestors and, what is more, digit loss and gain has occurred on more than one occasion over tens of millions of years.

根据他对 Bachia 家谱的分，有的物种从没有的祖先重新进化出，另外，头的得到和失去在几千万年间不止出现一次。