Evolutionary uniformitarianism

►I compiled data on the first occurrences of marine metazoan phyla and classes during the Ediacaran, Cambrian and Ordovician periods ►The patterns of origination illustrate the asymmetric pattern of major morphologic innovations during the Phanerozoic. ►These patterns of asymmetric origination are related to the construction of developmental gene regulatory networks, suggesting that the patterns of delivery of evolutionary variation have varied through time - in other words, that evolutionary processes are non-uniformitarian.