If the number of species present in both communities is 12, and community 1 has 5 unique species and community 2 has 3 unique species, what is the Jaccard community similarity index?

Question

Quizplus · Accepted Answer

The Jaccard index is calculated as the size of the intersection divided by the size of the union of the sample sets. Here, the intersection is 12 (species present in both communities), and the union is 12 (common species) + 5 (unique to community 1) + 3 (unique to community 2) = 20. Thus, the Jaccard index = 12/20 = 0.6.

If the Number of Species Present in Both Communities Is