Global extinctions and the biological evolution

Abstract

The biosphere evolulion is shown to accompany geodynamic processes and follow different-order cycle of the galactic motion of the Solar System. Restricted to critical points of the cycles are global epochs of nascencies and extinctions of taxa whose rank corresponds to a scale of geodynamic activation at their origin in critical points of the Earth's surface. Mutations are induced by a cyclic increase in cosmic radiation and provided by synchronous variations of geophysical flelds. Rhythmics of physical fields at taxa nascencies is fixed in genotype of organism to form their biorhythms and typical response degree to variations of the fields, reflected in stage-by-stage pattern of their life cycle. Desynchronization of the biorhythms with physical rhythms causes taxa extinctions or re-nascencies that is stimulated by simultaneous catastrophic changes in habitat conditions.