Strings 2008 2 6

How can biological sequences change

1. Point mutation or substitution - one base replaced by another

2. "Indel"

2.1 Deletion - loss of one or more adjacent bases

2.2 Insertion - adding one or more bases

3. Large insertions or deletions

• Tandem repeats of genes
• Transposable elements

4. Recombination - crossover and gene conversion (these are like cut-and-paste editing between two very similar texts)