Every paleontologist knows that most new species, genera, and families, and that nearly all categories above the level of family appear in the record suddenly and are not led up to by known, gradual, completely continuous transitional sequences.

Darwin recognized the fact that paleontology then seemed to provide evidence against rather for evolution in general or the gradual origin of taxonomic categories in particular.

Splitting and gradual divergence of genera is exemplified very well and in a large variety of organisms.

George Gaylord Simpson Quotes