Are there any examples of sudden leaps in evolution?
Zuk et al. (2006) document the rapid evolution of song-less crickets in a population of crickets that previously used song for courtship.

In less that 20 generations, over 90% of male crickets of the species Teleogryllus oceanicus evolved to a novel morphology ("flatwing") that rendered them unable to call to females. They hypothesize that this shift resulted from the presence of an North American invasive "acoustically orienting parasitoid fly." 

Basically the flies detect calling males and parasitize them, rendering them unable to reproduce. Were it not for the presence of the parasitoid fly, the flatwing flies would likely not have survived. Non-calling individuals rely on the presence of calling males to bring females near for mating.