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Force of Evolution 1: mutationMutationsoYou can imagine that it is fairly easy for DNA to make a mistake when copying the millions of proteins that make up the DNA code for an individual. But, in reality, mutations are relatively rare. oMutations can occur during both mitosis and meiosis, but ONLY the changes during meiosis that are passed down to gametes are a force of evolution.oAre changes in an individual’s DNA sequence oOut of 3.2 billion nucleotides in the human genome, each individual has ~ 58 new mutations that differ from their parentsRedundancyoNot only are mutations rare, but DNA has a way of preventing even more mutations. This is called Redundancy. oAs you know, an amino acid can be coded by several codons, but one codon can ONLY make one amino acid. It is like a safety precaution built into our DNA to protect against mutations (which are basically mistakes in copying the DNA). oEXAMPLEAlanine=CGA, CGG, CGT, CGCCGA=ONLY alanineoSafety net to protect against mustationsGenetic VariationoThink about this: evolution is only possible because of mistakes made when replicating DNA! There are several different types of mutations.oMutations are the ONLY source of new genetic variation in populations of organismsoYou can imagine, though, a simple mutation at one specific locus might cause problems if it changes the amino acid within a proteinTYPES OF MUTATIONS oMUTATIONSA point mutation is a change in one base of a DNA sequence.