The folks behind the Macarthur genius grant chose wisely this week when they gave one to Loren Rieseberg, an evolutionary biologist at Indiana University. Rieseberg does fascinating work on the origin of new species (that little subject). Specifically, he's shown how new plant species emerge from hybrids. When two species of plants form a hybrid, it doesn't necessarily become a sterile dead end. In fact, hybridization is an important source of entirely new species. Rieseberg does his work mainly on sunflowers, and so whenever I walk past a charming row of them, I think of the weird inter-species mingling that may lurk in their past.