Multiple factors, including the formation of the ‘developmental took kit’ whereby the same small number of genes control changes in body form for all known animals; the availability of the core tools of this kit over a billion years ago, long before the Cambrian Period; the ability of new body forms to be easily derived from old forms by minor modifications of the expression of tool kit genes rather than making new genes; the lack of modern levels of oxygen in the atmosphere until just before the Cambrian period; the availability of an empty ecological niche for the development of new species; and the accelerating effect that species diversification has on promoting further species diversification – all indicate that the Cambrian “explosion” was totally consistent with Darwinian evolution. [p62]
Explanation of the Cambrian explosion
Creationists and Intelligent Design proponents present the Cambrian explosion as a shining example of a phenomenon that evolution cannot explain. For them it is a prime example of the creative powers of a supernatural being. This became an exemplar of their cause by virtue of the fact that in Darwin’s time (1859) and in Charles Doolittle Walcott’s time (1900) knowledge about Precambrian life was non-existent. Not a single well-documented fossil had been found from any time before the Cambrian explosion, and the earliest evidence of multicellular life coincided with the earliest evidence of life. There could not be a better example of the creative touch of a supreme being. [p49]
