This process can overcome potentially lethal blockages, but at the cost of introducing inaccuracies in daughter DNA . The causal relationship of DNA damage to spontaneous mutation is illustrated by aerobically growing " E . coli " bacteria, in which 89 % of spontaneously occurring base substitution mutations are caused by reactive oxygen species ( ROS )-induced DNA damage.
22.
A number of observations associated with neutral mutation were predicted in neutral theory including : amino acids with similar biochemical properties should be substituted more often than biochemically different amino acids; synonymous base substitutions should be observed more often than nonsynonymous substitutions; introns should evolve at the same rate as synonymous mutations in coding exons; and pseudogenes should also evolve at a similar rate.
23.
The researchers concluded from testing that when metabolically activated, " PAs produce DNA adducts, DNA cross-linking, DNA breaks, sister chromatid exchange, micronuclei, chromosomal aberrations, gene mutations, and chromosome mutations " in vivo " and " in vitro " . " The most common mutation within the genes ares G : C-- > T : A tranversions and tandem base substitution.
24.
Genome comparison has shown that the RUBISCO spacer region ( located in the plastid DNA, between two subunits of the enzyme 1, 5-isphosphate carboxylase ) is highly conserved among closely related colonial " Phaeocystis " species and identical in " P . antarctica ", " P . pouchetii " and two warm-temperate strains of " P . globosa ", with a single base substitution in two cold-temperate strains of " P . globosa ".
