Joined: Jan. 2006
Speciation is not the mean by which evolution occurs. You can have evolution without speciation.
Regarding the aphid paper, the venom cathepsine gene copy is not found in related aphid species that don't produce venomous soldiers. They're just dodging the issue.
EDIT: scratch that, I didn't remember quite well what was said in the paper. The authors don't say if the gene copy is absent in non-venomous species. However, they do show accelerated evolution of the soldier-specific gene copy. There was a duplication of the cathepsine gene in the past (may be at the origin of the venomous species clade, or before) and the soldier specific copy evolved under positive selection (that involves non-synonymous mutations). Some "new genetic material" was involved it seems, however important this might be to these IDers.