Book excerpt: Natural Variances and Clocks, Volume 99 in the Advances in Genetics series provides the latest information on the rapidly evolving field of genetics, presenting new medical breakthroughs and advances. This updated release includes chapters on a variety of new research, including the Natural variation of the circadian clock in Neurospora, Natural variation and genetics of the photoperiodic timer in the pitcher-plant mosquito, Natural variation in human clocks, and Natural variation in the circadian clock genes in Drosophila and other insects. This series continually publishes important reviews that are ideal for geneticists and their colleagues in affiliated disciplines, critically analyzing future directions. - Critically analyzes future directions for the study of clinical genetics - Written and edited by recognized leaders in the field - Presents new medical breakthroughs that are occurring as a result of advances in our knowledge of genetics