For example, under the Studies tab, typing in "Coddington" and then clicking "Author" returns all Coddington studies. Then enter "Hormiga" and click "Author" and you see only two studies: ones with both Coddington and Hormiga. So each new criteria acts to further narrow the search against the last set of records. By contrast, the Taxa tab does not do this. First search taxon_variants for "Homo sapiens", then search taxon_variants for "Pan" and it behaves like a new search -- i.e. it does not use the second search term to narrow the result of the first. For consistency sake, all our tabs should behave the same way, which means narrowing based on a previous record set.