1 articles
  • Article Recirculation Lead Image

    Do Butterflies Challenge the Meaning of Species?

    Hybridization, it turns out, plays a pivotal role in how life forms evolve. The tree of life may never look the same.Photograph by sezer66 / Shutterstock What is a species? It’s a question that has agonized scientists since well before Darwin. With some exceptions, the thinking has landed on an evidently firm reproductive barrier: Members […]