Here’s an article from New Scientist that will be open for the next seven days to registered viewers. It’s about the “metamorphosis” of species from larval to adult stages, and brings in the views of Donald Williamson.
Here’s a link to his 2006 paper, and the entire abstract (it’s worth it!):
Examples of animal development that pose problems for Darwinian evolution by ‘descent with modification’ but are consistent with ‘larval transfer’ are discussed. Larval transfer claims that genes that prescribe larval forms originated in adults in other taxa, and have been transferred by hybridization. I now suggest that not only larvae but also components of animals have been transferred by hybridization. The ontogeny of some Cambrian metazoans without true larvae is discussed. The probable sequence of acquisition of larvae by hemichordates and echinoderms is presented. I contend (1) that there were no true larvae until after the establishment of classes in the respective phyla, (2) that early animals hybridized to produce chimeras of parts of dissimilar species, (3) that the Cambrian explosion resulted from many such hybridizations, and (4) that modern animal phyla and classes were produced by such early hybridizations, rather than by the gradual accumulation of specific differences.
Another day; another bad day for Darwinism!