Mean percentage difference
Mean percentage difference is the mean of the set of observed percentage
differences calculated for a particular pair of sequences.
That is, if Oqs = {oi : o1,
o2,
..., on} is the set of observed percentage
differences calculated from sequences Sq
and Ss
,
then mean percentage difference is ( ∑i oi
) / n.
Mean percentage difference is roughly the same as the overall
percentage of
base mismatches between the two sequences, when aligned, and therefore
can be viewed as a crude measure of overall evolutionary distance between Sq
and Ss
.
