This article describes a scientific study of Archaean genetic explosion by studying current DNA and extrapolating into the deep past. This provided a base of development for the Cambrian Explosion, but there is no explanation of the driving force behind such a gene expansion other than the apperance of more oxygen in the atmosphere as a correlation. Nor is there an explanation of why those genes were suddenly put to work and used. In studying history one can tell when certain events happened, but not the 'why'.

http://pandasthumb.org/archives/2011/04/the-true-story.html