From Wikipedia,
the free encyclopedia.
Nucleotide diversity is
a concept in
molecular genetics which is
used to measure the degree of
polymorphism within a
population. It was first
introduced by Nei and Li in
1979.
It is defined as the average
number of
nucleotide differences per
site between any two
DNA sequences chosen randomly
from the sample population, and is
denoted by Π.
It is given by the formula:
in which πij
is the proportion of different
nucleotides between the ith
and jth types of DNA
sequences, and xi
andxj are the
respective frequencies of these
sequences.
The summation is taken over all
distinct pairs i,j,
without repetition. That is:
where n is the number of
sequences in the sample.
