WAT is nu eigenlijk een soort? Helaas geen eenduidig concept maar verschillende soortsconcepten.
Morphological species concept a species is a set of organisms that are similar and that look different from other sets of organisms.
Biological species concept The biological species concept defines a species as members of populations that actually or potentially interbreed in nature The Western meadowlark (left) and the Eastern meadowlark (right) appear to be identical, and their ranges overlap, but their distinct songs prevent interbreeding.
Phylogenetic species concept a species is a “tip” on a phylogeny, that is, the smallest set of organisms that share an ancestor and can be distinguished from other such sets.
Rhododendron species concept species described and known only from cu1tivated material have not been accepted unless they are very distinct (even then, the possibility that they are of accidental hybrid origin must be borne in mind). species should differ from each other in at least two independent but correlatedly varying characters, and have geo- graphical or ecological distributions different from those of their closest allies. S1S2
Rhododendron species concept if two (or more) taxa appear to intergrade, then the resulting treatment depends on the proportion of intermediate specimens. If these are very few in number, two (or more) species are recognised, which a considered to hybridise to a small extent. S1-2 S1S2
If the proportion of intermediate specimens is larger (up to c. 25% of the total), but the units are geographically discriminate with the morphological intermediates in geographically intermediate area, then one species is recognised with two (or more) subspecies within it. S1 ssp.aS1 ssp.b a x b
Rhododendron species concept if the various units are geographically indiscriminate, then one species is recognised, eiter undivided, or if the morphological variation is appropriate, divided in two (or more) varieties.