Nikolay Wladimirovitch Timoféeff-Ressovsky: the man and the scientist. (1900-1981) -- TIMOFÉEF-RESSOVSKY: A SHORT ACCOUNT OF HIS LIFE -- FROM THE MUTATION THEORY TO THE THEORY OF THE MUTATION PROCESS -- N.V. TIMOFEEFF-RESSOVSKY'S VIEWS AS THE BASIS OF RADIOECOLOGICAL STUDIES -- LIVING MATTER AND BIOSPHEROLOGY -- Nuclear accidents and weapons -- RADIOECOLOGICAL ASSESSMENT OF THE CHNPP ACCIDENT IN THE WESTERN EUROPE AND ADJACENT AREA, WITH SPECIAL REFERENCE TO THE MODERN PROBLEMS OF RADIOECOLOGY IN THE MEDITERRANEAN -- DOSE RATES AND EFFECTS OF CHRONIC ENVIRONMENTAL RADIATION ON HYDROBIONTS WITHIN THE CHERNOBYL EXCLUSION ZONE -- EFFECTS OF CONTAMINANT EXPOSURE ON PLANTS -- VARIABILITY AND VIABILITY OF SEED PLANT POPULATIONS AROUND THE NUCLEAR POWER PLANT -- RADIOSENSITIVITY OF CHROMOSOME APPARATUS OF VOLES FROM ALIENATION ZONE OF CHERNOBYL'S ACCIDENT -- STRATEGY OF BIOLOGICAL RADIATION PROTECTION OF BIOTA AT THE RADIONUCLIDE CONTAMINATED TERRITORIES -- POPULATION-GENETIC CONSEQUENCES OF THE ECOLOGICAL CATASTROPHE (CHERNOBYL'S EXAMPLE) -- PRINCIPLES AND RESULTS OF GENETIC MONITORING OF CHEMICAL MUTAGENS AND RADIATION EFFECTS IN ARMENIA -- ESTIMATION OF SOMATIC GENE MUTAGENESIS IN PATIENTS WITH BENIGN TUMORS LIVING IN RADIATION CONTAMINATED REGIONS WITH DIFFERENT 137CESIUM DENSITY -- RADIOLOGICAL HEALTH EFFECTS 20 YEARS AFTER THE CHERNOBYL ACCIDENT: DATA OF THE NATIONAL RADIATION AND EPIDEMIOLOGICAL REGISTRY -- CASUALTIES AND RADIATION DOSIMETRY OF THE ATOMIC BOMBINGS ON HIROSHIMA AND NAGASAKI -- Radiation effects: the environment -- RADIOECOLOGY: HISTORY AND STATE-OF-THE-ART AT THE BEGINNING OF THE 21st CENTURY -- LOW DOSE RADIATION EFFECTS IN THE ENVIRONMENT: IS THE FEAR OR THE SCIENCE IRRATIONAL? -- RADIOCAPACITY: CHARACTERISTIC OF STABILITY AND RELIABILITY OF BIOTA IN ECOSYSTEMS -- TRITIUM IN WATER SYSTEMS OF URAL REGION -- THE PROBLEM OF MULTIPLE STRESSORS INCLUDING LOW DOSES OF RADIATION IN THE ENVIRONMENT -- Radiation effects: humans -- DIRECTED EVOLUTION OF MANKIND AND BIOSPHERE -- ASSESSMENT OF RADIATION GENETIC RISK IN MAN -- TARGETS, HITS AND TRACKS -- RADIATION CYTOGENETICS: THE COLOR REVOLUTION -- THE MINIMUM DETECTABLE DOSE BY BIODOSIMETRY IN A RADIATION OVEREXPOSURE -- A SIMPLE METHOD FOR THE EVALUATION OF SIDE DOSES IN RADIOTHERAPY -- MUTATION AND DNA REPAIR: FROM THE GREEN PAMPHLET TO 2005 -- CANALIZATION AND EVOLVABILITY: TEMPERING THE EFFECTS OF MUTATION IN A CHANGING ENVIRONMENT -- EFFECTS OF CHRONIC LOW-LEVEL IRRADIATION ON RADIOSENSITIVITY OF MAMMALS: MODELING AND EXPERIMENTAL STUDIES -- PROLONGED ENVIRONMENTAL STRESS INDUCES MUTATIONS AND PROVIDES NONSPECIFIC ADAPTATION OF DROSOPHILA POPULATIONS -- MODULATION OF MUTATION RATES AND ADAPTATION OF BACTERIA -- NUCLEAR CYTOPLASMIC INTERACTION HYPOTHESIS AND THE ROLE OF TRANSLOCATIONS IN NICOTIANA ALLOPOLYPLOIDS -- MOLECULAR DYNAMICS STUDY OF RADIOSENSITIVE MUTANT ALLELE OF PROTEIN KINASE ycdc28-srm [G20S] USING hcdk2 AS MODEL -- GENOME RECONSTITUTION IN THE EXTREMELY RADIATION RESISTANT BACTERIUM Deinococcus radiodurans. In September 2005, Yerevan (Armenia) hosted an International Conference dedicated to the 70th anniversary of the publication of the so called "green paper", published by N.W. Timofeeff-Ressovsky, K. Zimmer and M. Delbruck in 1935, entitled "On the origin of gene mutations and gene structure". The importance of this paper for genetics and radiobiology was enormous - not only for radiobiology, but for genetics in general. The "target" of the radiation action was indeed the "gene", that for the first time found a clear, operational definition. The organisers of this Conference proposed to convene scientists from all over the world to discuss the impact of radiation risk estimates in normal and emergency situations. This was the starting point of the NATO Advanced Research Workshop, whose proceedings are published in this book. The parallel development of the Conference and the Workshop resulted in a true synergism, both events taking advantage of the mixed environment of molecular biologists, genetists, radiobiologists, radioecologists, biophysicists, etc. gathered in Yerevan. We were delighted to include a few excellent papers dealing directly with Timofeeff-Ressovsky's life, and the "green pamphlet". The life and scientific achievements of Timofeeff-Ressovsky are often not well known in western countries, hence we deemed it advisable to include those papers in this book.