Tandem repeat regions are abundant in many genomes. Normally not very informative, except for various fingerprinting techniques using length statistics, regions where the repeats are marked, that is, there are slight variations of the basic repeat, remarkable patterns can occur.
These patterns can be utilized for evolutionary analysis, as has been demonstrated in (Savolainen et al, 2000a), and forensic analysis (Savolainen et al, 2000b).
Tandem repeats are believed to arise mainly from replication slippage, which causes repeats to be duplicated: A subsequence is copied twice during replication and the twin copies are found next to each other in the product. To take advantage this evolutionary artifact, we wrote two special computer programs.