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Aberations vs Variations
Posted: Tue Aug 27, 2013 7:38 am
by andy brown
Hi,
Have a few picture here for comment, and still not 100% sure what the difference is between an aberrant and a variation I think an Abb is due predominately weather/temp extremes and a variation is just that the butterfly can naturally vary in colour/pattern. Anyway here goes!
Open wing shot of Male Adonis on with Black Spots on inside of hind wing, Possibly an Variation.
Adonis with black spots on hind wings (not the same butterfly as above) instead of Orange taken from both sides, Possibly an Abb.
and Small copper with what I consider normal and one with fewer spots on forewing, Possibly an Abb.
Re: Aberations vs Variations
Posted: Tue Aug 27, 2013 8:38 am
by Padfield
Hi Andy. The literature is very inconsistent in its use of the words 'variation', 'aberration' and 'form'.
It is sometimes useful to distinguish between bell curve-type variation and discrete aberrant patterns caused by environmental or genetic factors - but even there it is not clear cut, as patterns off the end of the bell curve may be sufficiently extreme to merit the name 'aberration' and sufficiently rare that you find nothing in between. 'Forms' are best thought of as regularly occuring alternatives to the pattern, distributed geographically or as a percentage of a population.
Your Adonis blue with upperside spots shows bell curve variation. You will see Adonis blues with every gradation from no spots at all to very heavy spots. Your individual is somewhere in the middle - it is perfectly normal, though interesting.
I'm not sure about the other two. They are definitely extreme enough to be worth remarking, but whether they are limits of continuous spectra or discrete points I don't know - I suspect the former. Someone else will doubtless know for certain!
Guy
Re: Aberations vs Variations
Posted: Tue Aug 27, 2013 5:58 pm
by Pete Eeles
I agree with Guy's "bell curve thinking"! Typical definitions of variation-related terms can be found at:
http://www.ukbutterflies.co.uk/reports_variation.php
Cheers,
- Pete
Re: Aberations vs Variations
Posted: Wed Aug 28, 2013 12:57 pm
by MikeOxon
The whole subject of variation is huge and a major topic of current research in biology.
As well as all the genetic factors in Pete's article, there is the issue of how genetic expression is controlled and regulated. There's a wide range of mechanisms that are used by cells to increase or decrease the production of specific gene products (protein or RNA). In other words, it's not just the genes themselves that matter but when they come into play during the growth of a organism.
An example, in the case of butterflies, is the way patterns are formed on the wings. These depend on certain pigments being produced at controlled times during development. A dark spot requires production of the dark pigment to start at a specific time during growth and then stop at the appropriate time, If the timing goes awry, then a spot can appear in the wrong place or become elongated into a bar - such as is seen in some Common Blue aberrations. This explains why some types of aberrations occur and also why they are not consistent.
There's a lot more to be learned about how an organism grows and genes are just the start of the story.
Mike
Re: Aberations vs Variations
Posted: Wed Aug 28, 2013 2:34 pm
by andy brown
Oh dear sorry I asked
![Very Happy :D](./images/smilies/icon_biggrin.gif)
. 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.
Thanks Guys for your pointers
Andy
Oh and Pete I will read your report but probably on a dark winters night with a glass of wine or 2
Re: Aberations vs Variations
Posted: Wed Aug 28, 2013 3:12 pm
by Pete Eeles
andy brown wrote:It is obvious this is a whole minefield to tread.
I think it's quite straightforward
In terms of folder structure, I think it's good to begin with the end in mind, and separate out the various subspecies and forms, different broods (for some species) and different sexes. Here's a subset of my Lightroom folder structure:
![org.jpg](./download/file.php?id=39214)
- org.jpg (53.16 KiB) Viewed 437 times
Cheers,
- Pete
Re: Aberations vs Variations
Posted: Wed Aug 28, 2013 3:40 pm
by andy brown
Pete,
I will have to look at what to do with folders as all I have is adult, early stages and variations, it will just depend on how far I want to go with it. I do like the early stages so probably best to sort the folders out now rather than later. I also have the moths to think about and other insects. I am still sorting pictures out from 2012 to date so many hundreds to go through and ID. Plus I was out with Paul Brock today which was great and will undoubtedly mean many more insects and bugs to sort. I also have Lightroom and CS5 so will have to look at utilising them more rather than just folders on my disc drive.
Cheers
Andy
Re: Aberations vs Variations
Posted: Wed Aug 28, 2013 3:50 pm
by MikeOxon
andy brown wrote: with a glass of wine or 2
Now, that
is a good suggestion
![Smile :)](./images/smilies/icon_smile.gif)
Re: Aberations vs Variations
Posted: Thu Aug 29, 2013 12:07 pm
by NickMorgan
andy brown wrote:Oh dear sorry I asked
![Very Happy :D](./images/smilies/icon_biggrin.gif)
. 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.
Thanks Guys for your pointers
Andy
Oh and Pete I will read your report but probably on a dark winters night with a glass of wine or 2
Andy,
I am very pleased that you asked this. It is something that has been troubling me for some time!!
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. 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.
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 think I will also be cracking open a bottle of wine soon and reading that article!
![Wink :wink:](./images/smilies/icon_wink.gif)
Re: Aberations vs Variations
Posted: Thu Aug 29, 2013 1:03 pm
by Pete Eeles
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
![Smile :)](./images/smilies/icon_smile.gif)
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
Re: Aberations vs Variations
Posted: Fri Aug 30, 2013 11:00 pm
by ScottD
NickMorgan wrote:andy brown wrote:
Similarly with Small Coppers. Last year I noticed a lot of them were what is considered the caeruleopunctata abberation.
you may call it an aberration but I honestly believe that in Scotland (or at least parts of it) that it is the dominant form ...
(just to keep stirring the pot
![Wink :wink:](./images/smilies/icon_wink.gif)
)