Comparing evolution to a random walk with selection doesn’t quite sit right with me. In practice much of evolution occurs via gene duplication and recombination. At that point you can evolve complex changes very quickly. Evolving novel phenotypes is much easier if your starting material is an existing functional gene. Many motifs can be reused and reapplied.

Comparing a mule with it’s parents shows how much novelty can be produced in a single generation (in this case an evolutionary dead-end of course)