New chromosome-level evidence suggests Medicago evolution followed a more complex, and surprising path, than previously ...

Cell division during the early stage of embryo development is a trade-off between speed and accuracy; the cells need to ...

DNA does not float freely in the cell. Instead, it is wrapped around histone proteins to form structures called nucleosomes.

Cognitive scientists have long attempted to explain emotional processes using models that vary in complexity. These span very ...

IN Nature of April 21, p. 471, an article by Dr. I. Manton under this title was published. The accompanying illustration, however, was very unsatisfactory, due apparently to defects in the block.