Maximal Diversity is Early
From Gould, Gilinsky, and German
Asymmetry of Lineages and the Direction of Evolutionary Time
Evolutionary groups generally concentrate diversity during their early histories
Any taxonomic group builds to maximum diversity, and declines to extinction
They suggest that their documented temporal asymettry
may display a fractal character of self similarity at all scales
[Early] asymmetry arises when an initial emptiness permits unusual opportunity for diversification