# Address whether one overlap is significantly bigger that of another related overlap

#### pkd188

##### New Member
I could really use a hit as to which statistical test I need to use to address the following problem:

I have three different species: A, B and C. I have compared the quantitative overlap (i.e. something that was measured and counted in all 3 species) of Species A and B, respectively, with that of 'Species C' using a Fisher's test for each of the two cross-species comparisons.

In order to be more specific: When 'Species A' is compared to 'Species C' I get a p-value of 4.2e-08 (overlap of 17; 13 specific to A; 25 specific to Species C)

When 'Species B' is compared to 'Species C' I get a p-value of 0.014 (overlap of 7; 11 specific to B; 35 specific to Species C).

Now I want to determine whether 'Species A' mimics/replicates 'Species C' significantly more than 'Species B' does in terms of overlap. I'm assuming that a direct comparison between the p-values (from the two Fisher tests) isn't sufficient. So my question is which test I can use to address my problem?

Hits are much appreciated.