www.ukbutterflies.co.uk

I know a few of you are interested in physics, and so I have put an article I wrote last year as part of my degree online. If you want to learn about how butterflies use tiny structures in place of pigments to produce colour then I hope you will find it a good starting place.

I will be updating it soon to include sections on blacks, whites, UV signalling in Colias and some other structures. If you have any comments or suggestions I'd love to hear from you, also if there is anything you want explaining further, or indeed that I may have misunderstood, then say!

10MB PDF
http://www.hubbletelescope.btinternet.c ... ctures.pdf

Alexander Henderson

Hi Alexander
Sorry to be a pain, but my screen reader can't read PDF files
Have you got it in any other format that you could PM me or something?
you work sounds very interesting, I have studied Phontonic Structures before, but I have never applied it to butterflies. Probably because I was working on Genetics
I would certianly be interested in how you have applied it!
Em

Hi Mouse,

I'll see what I can do, I write with LaTeX which outputs directly to PDF. I'm sure there's some way around it.
AH

It's quite mind-boggling to think of these beautiful structures evolving over millions of years just by the blind forces of selection. So here's a question for you, Alex. Did each type of diffraction structure you describe evolve just once or did different groups come up with them independently? All your type III examples are Lycaenids - do only Lycaenids have this? And what about other insects, like beetles and dragonflies, that don't have scales? Is there another whole range of structures in their cuticles and wings?

With your permission I might use some of this material in my classes. I try to bring butterflies or Buffy into the lessons wherever possible and apart from an episode where Buffy goes invisible there's not much photonic interest in Sunnydale. We covered Bragg diffraction last term and only this morning I was talking about irridescent films of oil on puddles and that double vision you get in railway windows because of reflection off the near and far surfaces...

Guy

padfield wrote: I try to bring butterflies or Buffy into the lessons wherever possible and apart from an episode where Buffy goes invisible there's not much photonic interest in Sunnydale.

Guy

Fancy Teaching me Guy?

Some easy and hard questions there Guy!

1. Evolution of the structures. I know little about this tbh. The differing stimuli behind the structures means it's difficult to trace their evolution. What I can say though is that very similar structures are found in quite distantly related butterflies. For example type I structures are found in Morphos, Apatura and members of the Papilionidae. I think that the ability to produce a certain structure can be "hidden" or latent, and then reappear later making it more complicated. I have a paper hear about their evolution, but not being a biologist it's hard to understand. It says in the conclusion that currently much of it is speculative anyway.

2. Not Lepidoptera. There are countless other structures out there that work in amazing ways from birds' feathers to Jelly fish and Sea Mice. Dragonflys have structures on their wings thought to be used in courtship - something I will be reading up on soon Beetle elytra are also very interesting - I was involved in some research regarding some which absorbed left hand circularly polarised light, but reflected RHCP light!

If only!! There's not many students with your enthusiasm and study habits, Mouse!

Guy

padfield wrote:If only!! There's not many students with your enthusiasm and study habits, Mouse!

Guy

thanks Guy And there are not many teachers that are willing to help me with scary maths problems either, Guy
Em

I'm getting my lines all crossed and am losing replies I'm in the middle of making!

Thanks for your answers, Alex. I look forward to the full-colour book (illustrated by the author) that will doubtless appear in a few years time... The evolution of structures is always going to be a bit speculative. You can't just chuck them in a chromatograph and do statistics on them as you can with biochemical evolution. But it does seem that the scale is a very versatile organ that is capable of being modified in all sorts of interesting ways and quite possibly that the same modifications can pop up independently in widely separated taxa.

Looking forward to the next scary maths problem, Mouse!

Guy

A few years ago I received an email from a Professor Gunnar Björk of the Royal Institute of Technology, Stockholm, Sweden, on this subject. He was researching the blue colouring caused by the diffraction of white light in the regular microstructure that covers the wings of an example blue - Meleager's Blue (Meleageria daphnis).

He included these two links which may be relevant here:

http://www.psigate.ac.uk/spotlight/issu ... erfly.html

http://prola.aps.org/abstract/PRE/v67/i2/e021907