The first volume of Evolutionary Biology was published thirteen years ago. Since that time thirteen volumes and one supplement have appeared. As stated in earlier prefaces, we are continuing the focus of this series on critical reviews, commentaries, original papers, and controversies in evolu tionary biology. It is our aim to publish papers primarily of greater length than normally published by society journals and quarterlies. We therefore invite colleagues to submit chapters that fall within the focus and standards of Evolutionary Biology. The editors regretfully announce that Dr. William...