Functional rarity also called functional originality or trait originality is the characteristic of species (or any other biological unit) that makes it different relative to a well defined set.
Why are original species interesting? Original species can provide: irreplaceable trait, meaning that original species disappear no other species are going to present the same trait values in the set; original specis may also represent original ecological strategies, if the trait space represents the niche space well then original species show original strategies; finally original species can help uncover specific community assembly processes, or combination of processes because they are not well predicted nor accounted for by current theories.
Through the Functional Rarity in Ecology and Evolution synthesis group funded by the CESAB, we discuss and test new ideas regarding functional rarity.