This apparent anomaly is partially explained by the fact that most founder mutations are recessive: only a person with copies of the affected gene from both parents becomes ill.
While studying the genetic makeup of corn, a new class of mutant genes was discovered by Barbara McClintock, a discovery which led to greater understanding of cell differentiation.
Their allele frequencies at numerous genetic loci gradually become more and more different as new alleles independently arise by mutation in each population.
With their competitors all dead, the progeny of a mosquito carrying a mutation that can neutralise the insecticide in question have the world to themselves.
Mutations are the ultimate cause of all the genetic differences, including the differences between a human and a banana, between a starfish and a toadstool.
The viruses were made harmless and then genetically engineered to carry genetic material called RNA that would interfere with the faulty RNA produced by the mutant human SOD1 genes in the mice.
The results showed that petrochemical waste water and the polluted deep ground water all had significant mutagenicity on TA98. When S9 is not added, the mutagenicity was more significant.