42 lines
1.6 KiB
Markdown
42 lines
1.6 KiB
Markdown
|
# Hamming
|
||
|
|
|
||
|
|
Write a program that can calculate the Hamming difference between two DNA strands.
|
||
|
|
|
||
|
|
A mutation is simply a mistake that occurs during the creation or
|
||
|
|
copying of a nucleic acid, in particular DNA. Because nucleic acids are
|
||
|
|
vital to cellular functions, mutations tend to cause a ripple effect
|
||
|
|
throughout the cell. Although mutations are technically mistakes, a very
|
||
|
|
rare mutation may equip the cell with a beneficial attribute. In fact,
|
||
|
|
the macro effects of evolution are attributable by the accumulated
|
||
|
|
result of beneficial microscopic mutations over many generations.
|
||
|
|
|
||
|
|
The simplest and most common type of nucleic acid mutation is a point
|
||
|
|
mutation, which replaces one base with another at a single nucleotide.
|
||
|
|
|
||
|
|
By counting the number of differences between two homologous DNA strands
|
||
|
|
taken from different genomes with a common ancestor, we get a measure of
|
||
|
|
the minimum number of point mutations that could have occurred on the
|
||
|
|
evolutionary path between the two strands.
|
||
|
|
|
||
|
|
This is called the 'Hamming distance'.
|
||
|
|
|
||
|
|
It is found by comparing two DNA strands and counting how many of the
|
||
|
|
nucleotides are different from their equivalent in the other string.
|
||
|
|
|
||
|
|
GAGCCTACTAACGGGAT
|
||
|
|
CATCGTAATGACGGCCT
|
||
|
|
^ ^ ^ ^ ^ ^^
|
||
|
|
|
||
|
|
The Hamming distance between these two DNA strands is 7.
|
||
|
|
|
||
|
|
# Implementation notes
|
||
|
|
|
||
|
|
The Hamming distance is only defined for sequences of equal length. This means
|
||
|
|
that based on the definition, each language could deal with getting sequences
|
||
|
|
of equal length differently.
|
||
|
|
|
||
|
|
|
||
|
|
## Source
|
||
|
|
|
||
|
|
The Calculating Point Mutations problem at Rosalind [view source](http://rosalind.info/problems/hamm/)
|