The delta variant of the coronavirus is here. It’s scary. It seems to spread more easily than any of the variants we’ve seen so far. It’s quickly becoming the dominant strain of the virus, outcompeting other strains. But it may not be the last. Watching the news about delta, I keep wondering: What’s next? How might SARS-CoV-2, the coronavirus that causes Covid-19, continue to evolve? After all, the work of evolution is never over. Change is constant. A year from now, might there be an omega variant that’s twice as transmissible as delta? “The big answer to your question is...