Explosions of intragalactic supernovae as one of the possible external factors of the macroevolution of organisms on Earth

Explosions of near supernovae (a source estimated at 1056 to 1057 MeV) producing a high intensity of gamma and X radiation even after its reduction through the Earth atmosphere may have significant mutagenic action. The most probable distribution of the supernovae of the 2nd type from the Earth in the period of 109 years is one hundred supern--ovae up to the mean distance of 20O pc; and during the period of the last 4x109 years one-hundred explosions up to the mean distance 126 pc from the Earth. All such explosions were able to evoke a genetic revolution among most taxonomic groups of terrestrial organisms. For montane organisms the more frequent but distant (up to 400 to 900 pc) supernova explosions are of importance. Maritime organisms could be influenced mainly by secondary radiation products, rather than directly by the gamma- and X-rays from the supernovae. The mechanism of macroevolution depending on supernovae is elucidated. Smaller genetical revolutions in the macroevolutional process (formation of genera) took place on the average once in every 107 years or more, fundamental genetic revolutions once in every 108 years or more. (author)