41. It has been shown that altering Dam activity in bacteria results in increased spontaneous mutation rate . 42. Deficiencies in DNA repair cause increased mutation rates . 43. In 1932 he published six scientific works and discovered the formula of mutation rate in humans. 44. That is not necessarily due to a higher mutation rate , but to lower levels of purifying selection. 45. The mutation rate was estimated to be ~ 10 " 6 substitutions / site / year. 46. Mutation rates just provide a background rate of variability for which natural selection can then act upon.47. Jeffreys and Dubrova discovered that the mutation rate had increased substantially in the offspring of irradiated mice. 48. The natural mutation rate in such genes is so low that measuring a radiation-induced change is impossible. 49. Mutation rates differ between species and even between different regions of the genome of a single species.50. Some viruses employ polymorphic code in a way that constrains the mutation rate of the virus significantly.
