structural:scholar_edition
The Cambrian explosion as survivorship bias

Budd and Mann suggested that the Cambrian explosion was the result of a type of survivorship bias called the " Push of the past ". As groups at their origin tend to go extinct, it follows that any long-lived group would have experienced an unusually rapid rate of diversification early on, creating the illusion of a general speed-up in diversification rates. However, rates of diversification could remain at background levels and still generate this sort of effect in the surviving lineages.