When these tests were applied to online repositories (like the Corpus of Historical American English), they found cases where natural selection favored regularized verb tenses (“smelled” instead of “smelt,” for example).
Plotkin and his colleagues performed statistical tests to weed out cases where natural selection is at play (versus drift). When these tests were applied to online repositories (like the Corpus of Historical American English), they found cases where natural selection favored regularized verb tenses (“smelled” instead of “smelt,” for example). They also found cases where natural selection pointed to irregularity: “dove” instead of “dived.” They posited that “dove” replaced “dive” around the same time that cars were becoming popular, which means we were using words like “drive” and “drove,” given that we might have a tendency to choose words that sound alike. This is not unlike the observation noted by Grammar Girl in a recent podcast episode, which is that sound changes eventually affect every word that carries the sound: “pater” to “father,” “pire” to “fire,” “ped/pod” to “foot.”