Finch and Kirkwood have written a great and insightful book reviewing the premise that chance, operating during the fetal development of an organism, has a significant influence on all future physiological events during the postnatal life of the organism. These intrinsic developmental variations lead to seemingly subtle and, until now, thought to be insignificant, physiological differences between organisms. Finch and Kirkwood convincingly argue that these subtle physiological differences have a significant impact on later events during the life of the organism. For example, whether a given individual will get sporadic Alzheimer's disease or Parkinson's disease. Also, the same variations would have an impact on the severity of the disease (should a person get the disease). This book is a must for any biology scientist serious about having a complete library on her/his shelves.