This book will explain the colossal potential of life to cope with different living environments is possible owing to the exceptionally well developed mechanisms of adaptation to environmental conditions. There is an innumerable variety of concrete mechanisms which make it possible for living creatures to adapt to different and changing environmental conditions. Nevertheless, all this variety is the manifestation of the three strategic line of the adaptation process: 1. Evolutional or genotypic adaptation. 2. Phenotypic adaptation. 3. Rapid adaptation.