Force of Evolution 1.docx - Force of Evolution 1 mutation Mutations o You can imagine that it is fairly easy for DNA to make a mistake when copying the

Force of Evolution 1.docx - Force of Evolution 1 mutation...

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Force of Evolution 1: mutation Mutations o You 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. o Mutations can occur during both mitosis and meiosis, but ONLY the changes during meiosis that are passed down to gametes are a force of evolution. o Are changes in an individual’s DNA sequence o Out of 3.2 billion nucleotides in the human genome, each individual has ~ 58 new mutations that differ from their parents Redundancy o Not only are mutations rare, but DNA has a way of preventing even more mutations. This is called Redundancy. o As 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). o EXAMPLE Alanine=CGA, CGG, CGT, CGC CGA=ONLY alanine o Safety net to protect against mustations Genetic Variation o Think about this: evolution is only possible because of mistakes made when replicating DNA! There are several different types of mutations. o Mutations are the ONLY source of new genetic variation in populations of organisms o You can imagine, though, a simple mutation at one specific locus might cause problems if it changes the amino acid within a protein TYPES OF MUTATIONS o MUTATIONS A point mutation is a change in one base of a DNA sequence.
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