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In amongst the profusion of roosting Chalkhill Blues this evening, I took the opportunity to see how prevalent aberrations might be on the underside markings. In previous years there have always been a few of these, though the markings are pretty variable within the "normal" range.

I spotted two that might qualify - depicted below. These represent less than 1% of those examined, I would say at a guess.

Dave

Here are three different Chalkhill females from 28th at Aston Rowant. None seem to quite fit with the standard model, but are any sufficiently diverse to be considered aberrant?

Dave

The first 2 definitely are. The middle one in particular!

Cheers,

- Pete

Thanks, Pete - I thought the middle one was particularly unusual (pity the image wasn't better ). No wonder in the days of collecting, vast numbers of this species were amassed and catalogued. There seems to be a huge variety.

Dave

As an observation, most of the abberant postings of Chalkhill blues (or any blue for that matter) show the undersides, with spots either missing or distorted. However at Susies Denbies trip I couldn't help noticing that the males showed variation in their uppersides too. These differences though subtle were not due to wear and tear, nor I believe, to the angle of the light. Most nocticable was the depth of the blue with some showing pale colouration and others darker. As the blue colour is not due to a pigment, for this to hold true there must be some differnces in the scaling either in the structure, size or layout on the wing membrane (perhaps someone can clarify this point?) The extent of the dark edging also varied. Most of the pictures of abberants focus on the undersides for obvious reasons (and female uppersides usually due to differences in the extent of the blue scaling) but I don't think the uppersides of the males should be overlooked either.

I would also be interested ton know at what point a 'normal variant' becomes an aberrant. Replicates will always show variation around a mean but does the definition of aberrant kick in? (apologies if this has been explained before ) And WRT the Chalkhill Blues which seem to show lots of aberration, is it possible or practical to try and classify them? Probably not, rather a perfect excuse to go kill an collect in the 'interests of science'.

Believe it or not, Bright and Leeds tried just this - resulting in "A MONOGRAPH OF THE BRITISH ABERRATIONS OF THE CHALK-HILL BLUE BUTTERFLY" which details over 200 aberrations (if I remember correctly).

I've no idea what constitutes an aberration. No definition I've come across holds up to scrutiny, and typically requires some agreement of what "normal" is first! So - all a bit subjective I'm afraid!

Cheers,

- Pete

I suspect there is at least a small, perhaps unconscious, legacy of creationism in the concept of an aberration, i.e.: the idea that all of nature can be divided into discrete classes, species, each with its divine archetype in the mind of the creator. Deviations from that archetype are aberrant - a word with connotations of something going 'wrong'. If you acknowledge nature to be more fluid than this - crystallising out on its own and shifting over time rather than being created to a plan - the word 'aberration' seems less appropriate. I think there is also a legacy of the Biblical concept of dominion in the obsession with giving names to each and every form (Genesis 2.19: "So out of the ground the LORD God formed every beast of the field and every bird of the air, and brought them to the man to see what he would call them; and whatever the man called every living creature, that was its name).

If only because of an aversion to both legacies, I'd probably like to see the word 'aberration' gradually phased out in favour of more neutral descriptions of variation, rather than better defined!

Guy

PS - this was intended as an observation, not an invitation to a religious discussion, which would risk breaching forum rules, I think!

padfield wrote:I'd probably like to see the word 'aberration' gradually phased out in favour of more neutral descriptions of variation

Your historical background is interesting. I think that aberration only exists in the eye of the beholder.

Now that many people have built up a good collection of photos, we seem to have reached the same stage as our Victorian forebears: - seeking out something 'different' for our collections.

Mike

Thanks for your replies Pete; Guy and Mike.

Pete Eeles wrote:Believe it or not, Bright and Leeds tried just this - resulting in "A MONOGRAPH OF THE BRITISH ABERRATIONS OF THE CHALK-HILL BLUE BUTTERFLY" which details over 200 aberrations (if I remember correctly).

I expect after 200 they gave up unable to sub-divide anymore? I suppose you could infer that this would've been done, after all there isn't anything that humankind hasn't tried to explore.

padfield wrote:Deviations from that archetype are aberrant - a word with connotations of something going 'wrong'. If you acknowledge nature to be more fluid than this - crystallising out on its own and shifting over time rather than being created to a plan - the word 'aberration' seems less appropriate.

I agree with you Guy if I understand you correctly Genetic mutation drives evolution but this word like aberration, also carries negative connotations as many 'mutants' fall foul of natural selection. In this case subtle mutations in relation to wing patterning don't appear to have detrimental effect on the individual (or are we (wrt ChB's) talking about a problem with gene expression being impacted on by the environment:- the 'aberration' (deformity?) caused by it being too hot, cold or some other environmental factor?) If this is the case and they are one-offs, is it likely that their progeny will be 'normal' under favourable environmental conditions? Is this a 'built-in buffer zone' for species survival should there be an environment shift? .... it is difficult to see where wing patterning could help a species .

Whatever, Pete and Guy you've explained that there is no clear definition.

MikeOxon wrote:Now that many people have built up a good collection of photos, we seem to have reached the same stage as our Victorian forebears: - seeking out something 'different' for our collections.

I must admit, wrt to Chalkhill Blues its a bit like shooting fish in a barrel for want of a better way of putting it due to their sheer number. My personal preference with butterfly photography is to capture the aesthetics of the creature or something that is rarely seen. The Chalkhill aberrants at Denbies were to my mind, aesthetically less pleasing and definitely not rare. As a result they didn't hold much interest for me above the norm. Put it this way I certainly won't be going out of my way to recreate a photographic record of Bright and Leeds.