Dr. William E. Evans is a Professor Emeritus of the Marine Biology Department, Texas A&M University. He received his B.Sc. from Bowling Green State University, his M.Sc. from Ohio State University and his Ph.D. from the University of California, Los Angeles. He was director of the Sea World Research Center (San Diego, USA), Chair of the US Marine Mammal Commission, Director of the National Marine Fisheries Service and the Undersecretary of Commerce and head of NOAA. Dr. Evans - author of several hundreds papers in marine mammal acoustics, population biology, remote sensing technology and fisheries. He is Chief Editor of the American Midland Naturalist.

Dr. Alexey V. Yablokov is a chief scientist of N.K. Kol'tzoff' Institute of Developmental Biology, Russian Academy of Science. B.Sc. (Moscow State University, 1956), M.Sc. (A.N. Severtsoff' Institute of Animal Morphology, Moscow, 1959), Ph.D. (Biological Division, Siberian Branch the USSR Academy of Science, Novosibirsk, 1965). He is the author about 500 publications on mammals, populational, evolutional and conservational biology, including about 20 books, translated from Russian to English, German, Japanese etc. Dr. Yablokov is President of the Center for Russian Environmental Policy. He was President of the Moscow Society for Protection of Animals (1990-2001), and Vice President of the World Conservation Union (2000-2004).

This is the first book concerning a non-invasive approach to the study of mammalian populations in nature. Frequencies of detectable individual variations (structural, behavioral, acoustic etc.) allow to investigate both intra- populational structure and inter-populational dynamics: the geographical distribution of natural populations, genetic interrelationships between populations as well as in small within-population groups like families, demes, pods etc., and to understand intra-populational changes and phylo-geographic (micro-evolutionary) patterns. Based on studies of individual variation in whales, dolphins, seals (coloration, vibrissae counting, acoustics etc.), the authors analyze the prospects for non-invasive research in all mammalian groups. In individual chapters, a potential for non-invasive studies of color patterns, acoustics, behavior and some structural features is discussed, including hundreds of qualitative variations in nose, ear, tooth, eye and tail morphology, in dermatoglyphics etc. Non-invasive methods for studying the population phenetics (the frequencies of qualitative detectable variations, or phenes, which reflect the genetic characteristics of the population) are set forth. Discrete phenotypic variations in organs are listed systematically for all main groups of mammals.