Local Alignment(BLAST) and statistics
Blast is an algorithm for comparing primary biological sequence information, such as the amino-acid sequences of proteins or the nucleotides of DNA sequences. By doing so, it enables a researcher to compare a query sequence with a library or database of sequences, and identify library sequences. it is also one of multiple algorithms developed for the analysis and comparison of biological sequences such as DNA, RNA, and proteins. Different types of BLASTs are available according to the query sequences. For example, following the discovery of a previously unknown gene in the mouse, a scientist will typically perform a BLAST search of the human genome to see if humans carry a similar gene; BLAST will identify sequences in the human genome that resemble the mouse gene based on similarity of sequence
https://en.wikipedia.org/wiki/BLAST
