This year I took some time to photograph Ringlets having noticed quite a bit of variation. I noticed that they were almost all different from eachother and displayed a complete range of variation.[/quote]
Indeed - and phrases such as "xxx is within the normal bounds of variation" are often used to handle this.
NickMorgan wrote:A couple of them were at the extremes which corrolate with aberations, but it left me wondering where the cut-off is between variation and them being considered an abberation.
An aberration is one type of variation where, in general terms, an aberration is supposed to represent a "one off" or very rare occurrence. Certainly something that isn't considered within the normal bounds of variation.
NickMorgan wrote:Similarly with Small Coppers. Last year I noticed a lot of them were what is considered the caeruleopunctata abberation. However, this again varied from a single blue scale on each hind wing to four large distinct blue dots. Would these all be considered to be abberations? Surely just one scale on each wing is just a slight variation?
I personally find
ab. caeruleopunctata problematic, for the simple reason that I find this to be within the normal bounds of variation - and therefore contradictory to the common understanding of what an aberration is! If you read the article you'll see it called out for this reason
I've just re-read the definitions of the various types of variation in the article mentioned, and they sound pretty clear to me!:
Subspecies: Populations of a given species that share distinct morphological and/or genetic characters, separating them from other populations. The population is invariably isolated from other populations. An example is the subspecies ssp. caernensis which is the subspecies of Silver-studded Blue found on the Great Orme.
Form: The term applied to dimorphism (where a butterfly occurs in two or more distinct colour types) [Vigus]. Sexual dimorphism, seasonal dimorphism and geographic dimorphism are often described using named forms. An example of sexual dimorphism is the form f. valesina of the female Silver-washed Fritillary. An example of seasonal dimorphism is the form f. hutchinsoni of the Comma. An example of geographic dimorphism is the form f. scotica of the Mountain Ringlet.
Aberration: An individual that differs from the norm. An aberration is usually a “one off” in the sense that it does not recur predictably. An example is the Ringlet aberration ab. lanceolata in which the rings are teardrop-shaped.
Cheers,
- Pete
. It is obvious this is a whole minefield to tread and something I will probably only dabble with should I get something extraordinary to identify. I shall change my folder structure for each butterfly to have the folders say variations rather than aberrations as it is probably safer.
