Keywords: heterozygosity, mutation pressures, molecular evolution, evolutionary perspectives, neutral theory, radiation exposure, low radiation, background radiation
Radiation exposure and evolutionary perspectives with special references to neutral theory
The truncated natural dose commitment for various periods since the assumed appearance of some of our ancestors may be calculated to have been much higher than for the present period. Background radiation has been a universal component of our environment. Radiation-adaptive response and, possibly, hormesis may be claimed to be an evolutionary expectation. It may also support the cause of the neutral theory, which states that the molecular polymorphism observed in natural populations is due to neutral mutation under drift equilibrium. In the wake of the findings of the Human Genome Project, the neutral theory is worth revisiting, since mutations are selectively neutral and long-term heterozygosity reflects only the population history and mutation rate. The neutral theory considers that genes and proteins are very well adapted because of the past natural selection brought about by the pressure of the radiation environment that facilitated its drift.