The cover shows many facets of genetics. Top row, Left: The DNA double-helix, here imaged in a scanning tunneling micrograph, is central to all genetics research. Right: Experimentation has shown that some social behaviors, such as nest cleaning by honeybees, is under genetic control. Second row, Left: Inherited disorders such as albinism, manifested here in a bullfrog, have provided many insights about the genetic control of metabolism. Right: Gregor...