Story one: Roots of monogamy feed scientific spat: Researchers clash on how fidelity evolved in mammalian species.

The article discusses disagreement between two research groups on the evolution of monogamy in mammalian species. Topics include primate research by Dieter Lukas and Tim Clutton-Brock from the University of Cambridge in England and Kit Opie of University College London, England and colleagues, the role of infanticide and distance between females in the evolution of monogamy, and a discussion of factors influencing the outcome of each team's study.