Names that were previously treated as synonyms of a subspecies and USED as form names in a polymorphic species may be used as subspecies in the case that they were originally described as a species or subspecies (this includes names described as a form or variety before 1961 as long as they were originally described in a geographical sense rather than as a sexual or individual variation) but if they were described as an aberration or the original description clearly indicates the name is infrasubspecific (such as a different coloured individual given a name) then the name cannot currently be adopted with its original author/year as an available name. Thus it is important to examine the original description of each name, and for a separate geographical population the oldest available name becomes the valid subspecies name IF subspecific or specific separation is warranted.
However,
Forms of the same subspecies may appear individually SLIGHTLY different at the individual gene level, in the same way as people with blue or brown eyes would, but this genetic difference would be minimal, and is just individual variation in a single population. Particularly in polymorphic mimetic butterfly species local selection pressure on individual appearance can have significant effects. For example in the P. glaucus group the presence or absence of a dark female form probably depends more on the presence or absence of the model (Battus philenor) but may also depend on other unclear factors where the model does not occur but the dark form is still present. For instance perhaps the predators move around and learn to avoid the dark distasteful butterfly elsewhere and then subsequently avoid any they meet among the P. glaucus in a different place and/or time. It is worth noting that this can also be a temporal difference ... the model may have been flying weeks or even months before the mimic, but the predators in the same place associate the colour with a nasty event and remember it.Chuck wrote: ↑Fri Dec 06, 2024 6:03 pm So what of those various regional "forms"? Suddenly when a ssp is elevated to sp, NOW it too can have ssp, so some of those forms- which are not- can be taxonomically recognized. This is not new, though it seems genetic analysis has drastically increased this situation.
Not at all. Bear in mind that the ICZN Code governs NOMENCLATURE, not taxonomy. The Code tells you how to treat names proposed by taxonomists and which names can and cannot be used. It is up to the taxonomists to apply the 'rules' in order to choose the valid name for any taxon THAT NEEDS A NAME, excluding names that do not conform to the 'rules' of the Code. Bear in mind that each branch of a tree is a 'taxon' but they don't ALL need scientific names.
Any names originally proposed below subspecies level (= infrasubspecific) are unavailable under the Code and cannot be used as valid names (see above), but if a taxonomist decides that a POPULATION is worthy of subspecies status but does not have an available name that can be used as the valid subspecies name the taxonomist will describe a new subspecies, thus providing an available name to use.
I repeat, the ICZN does not set ANY taxonomic 'rules', only regulations governing nomenclature, as I stated above. This is a slightly subtle issue to grasp, but there is a distinct difference between nomenclature (how animals are named) and taxonomy (how they are related to each other). The Code does not set rules about how to distinguish a species or subspecies, or indeed a genus or a family, it just governs the names that taxonomists should use once they have decided how to classify the animals they study.
Note that in the case of angelfish the different coloured ones in captive breeding are probably like comparing different breeds of dogs. A Chihuahua is genetically not different to a Great Dane and does not deserve subspecies status, so the different coloured angelfish are not actually subspecies. It is possible that different rivers contain individual colours, but ichthyologists do not separate subspecies as much as lepidopterists for various reasons which they have opinions about, and as they all interbreed they are clearly the same species. Similarly the pigeons around here can be a number of different colours (white, grey, mixed etc) but they are all the same taxon and they all interbreed. Different branches of Zoology have their own way of classifying populations, based on criteria relevant to the animals they study. Some recognise subspecies, others do not, usually with reasons based on the individual biology of the type of animal.
Adam.
