where a is the number of taxa that are present in both samples and c is the number of taxa that are present in one sample and absent in the other.
where a is the number of taxa that are present in the modern sample, b is the number present in the fossil sample, and c is the number of taxa that occur in both samples.
where the sums are calculated as i goes from 0 to n-1
<http://geochange.er.usgs.gov/pub/tools/analog/doc/distance.html>
Maintained by Peter Schweitzer
Last updated 8-Apr-1999