Sunday, 27 September 2009

Cheering-up-plant- Stapelia flavopurpurea

(c) Martin Heigan, reproduced with permission.

In place of a cheering-up bird this week, I have this stunning image, taken by Martin Heigan, of the flower of the succulent plant Stapelia flavopurpurea. There are around 40 plant species in the genus Stapelia -the so called "carrion flowers". This species is notable for having a sweet, pleasant smell, unlike its relatives, which typically smell of rotting flesh- hence their name. This picture was taken in South Africa, but this plant also grows in Namibia.

Mr Heigan has whole set of photos of carrion flowers and their relatives on flickr, which is well worthy of a detour- you can find them here-

His picture of the oddly geometric flowers of "the wax plant",Hoya carnosa " is particularly impressive-

Thursday, 24 September 2009

Quote of the Week- Sydney Altman- privileges

"We are privileged to have been afforded the opportunity to study Nature and to follow our own thoughts and inspirations..."
Sydney Altman, Canadian Molecular Biologist and Nobel Laureate (b. 7th May 1939)

Tuesday, 22 September 2009

“Flashing Butterflies” (Science in plain English)

I recently received a package of reprints for a scientific paper I contributed to. The paper was on colouration in two neotropical butterflies. Having worked for so long in the field of colouration (sic), at the moment, I am in two minds about revisiting projects in the subject, let alone, blogging about them. In this case, I really like some of the underlying scientific idea, so it seemed worth writing a popular science version of them. This was originally supposed to be a teaching aid/ class-discussion resource for educational purposes, so you will have to excuse me if the tone is a bit didactic in places:-

Mercedes atnius and Morpho rhetenor are two day-flying butterflies that live in the same tropical habitat (pristine forests of Guyana and in the lower Amazon basin in South America). When observed with the naked eye, museum specimens of these insects seem to exhibit an identical blue colouration, but this is deceptive because living butterflies of different species flap their wings differently, giving rise to various optical effects. Dead animals, which look alike in a museum case, may look very different from each other when they are alive, in the wild.

Different species vary in their wing-beat frequencies and this variation is not always for reasons of aerodynamics or to conserve energy. In fact, in some butterflies, characteristic wing-beat frequencies have evolved which are known to be aerodynamically costly but which have a role in signalling to other butterflies.

We should consider this signaling for a moment- it is as if the pattern of pigment on the wing in these butterflies acts as a coloured display, which is alternately visible and not, as the wings open and close. This means that the pattern of display seen over time depends on the wing-flap frequency, allowing butterflies to distinguish between other members of their own species and similar species with the same wing colouration. This phenomenon has already been investigated in some butterfly species, but the situation is much more complicated in the butterflies Mercedes atnius and Morpho rhetenor .

There are essentially three ways in which living organisms can produce colouration: by using pigment, by using bioluminescence (carrying out chemical reactions that give off light of certain colours) or by reflecting certain colours (wavelengths) of incoming light and not others. This last method- better known as “structural colouration” -is the cause of the bright colours in metallic beetles, the feathers in a peacock’s tail and the shiny metallic blue colouration in many butterflies of the rainforest. Mercedes atnius and Morpho rhetenor are two such butterflies. They both have a vivid metallic blue colouration on the upperside of their hind-wings’ surface, which "flashes" as the butterfly is tilted.

Detailed examination of their wings reveals that, like all butterflies they are covered in scales. However, within the scales in these two butterflies are masses of tiny, highly organized and repetitive structures. Because of their precise geometry and dimensions, these structures are able to interfere with any light landing on them. They amplify certain colours (wavelengths) of light, whilst colours either pass through the structure or disappear within it. In fact, the wing structures reflect and amplify blue light, which is why the butterflies appear blue. The wings reflect light much more strongly in some directions than others. (the reflected light is highly directional)

When flying, a butterfly with this type of structures in the wing scales can produce some arresting visual effects, because not only does the pattern on its wings appear and disappear, or flicker, but at certain, precise, angles, there are also bright flashes as the wings reflect light very strongly.

This may sound complicated enough, but it is not the end of the story because it is not just the strength of reflection that varies with angle, but also- slightly- the colour of the light reflected. The result of this is that there are three visual effects occurring simultaneously in the butterflies Mercedes atnius and Morpho rhetenor. With each wing flap, the coloured display from the wings of these species will not only become visible or not (flicker) as the wings open and close, but it will also vary in colour as the wing angle changes and in intensity (show bright flashes).

Because the consequences of wing-flapping had not previously been investigated in species like these (with colour- producing structures in their wings) this scientific paper discusses these flashes. In particular, it considers the idea that their frequency could be a way for these butterflies to recognise other individuals of the same species. Obviously, this is a phenomenon that will require more detailed discussion in the future, but this paper makes a start by studying museum specimens of these two butterflies, in order to understand the signals they emit better. All of which is a necessary prelude to investigations into the flicker phenomenon and to studies of these "flashes" in the wild and their behavioural significance.

This study was published as “Morpho-like optical phenomenon in the neotropical lycaenid butterfly Mercedes atnius”, (Zsolt Balint, Serge Berthier, Julie Boulenguez & Victoria Welch,) in the journal Atalanta (sic), 40 (1/2), 263-272, Wurzburg, 2009 (ISSN 0171-0079).

Sunday, 20 September 2009

Cheering-up bird 7- Anna's Hummingbird

This week's cheering-up bird is a male Anna's Hummingbird (Calypte anna). "Anna" in this case was Anna Massena, 2nd Duchess of Rivoli, who lived in the 19th Century and whose husband was a keen amateur ornithologist (as well as being a Duke and Prince...). This beautiful species lives on the west coast of North America.

This picture was taken by Janine Russell and originally posted here-

Friday, 18 September 2009

Quote of the Week- Paul Nurse- importance of biology

"Better understanding of the natural world not only enhances all of us as human beings, but can also be harnessed for the better good, leading to improved health and quality of life."
Paul Nurse, Nobel Laureate

Wednesday, 16 September 2009

Pink Insects

There seems to have been surprisingly little by way of science news in the headlines this week, but I did come across this link of some recently discovered mutant insects with pink colouration: (both weird and beautiful)...

Tuesday, 15 September 2009

Ever wondered what a Nobel Prize looks like?

If you have ever wondered what a Nobel Prize looks like (apart from the money), the answer is here- 2 certificates (in Swedish) and a medallion.

No prizes for guessing who won this particular Nobel prize... Actually was donated by Einstein (indirrectly) to the Bloomfield Science Museum in Jerusalem, where it is on public display.

The museum is right beside the Hebrew University, in the Givat Ram district of the city. It is mostly targetted at children with a number of interactive displays, but it does have a room devoted to Albert Einstein, complete with letters by him, school reports on him and facsimiles of the original maunscript of special (?) general (?) relativity, complete with crossings out. I found it enormously heartening to see that even Prof. Einstein himself occassionally made mistakes. photos (c) V Neblik, 2008

Sunday, 13 September 2009


As promised, this week's cheering-up animal is a REAL LIVE DINOSAUR.
The world's only living dinosaur species, in fact ( I'm ignoring birds here, for the sake of argument). It's a tuatara from New Zealand.

This image is by Ian McHenry of Christchurch, New Zealand, who owns the copyright. Reproduced with permission. You can see this image and the rest of Ian's photostream (which contains lots of wildlife images) at . He also has a collection of images online at , including some lovely pictures of a Kea.

Friday, 11 September 2009

Quote of the Week- Marie Curie- People and things

"Be less curious about people and more curious about ideas."
- Marie Curie

Thursday, 10 September 2009

Autumn toadstool

(c) Victoria Neblik, 2009.
my best guess is that this slowly rotting toadstool is species of Coprinus, related to the Autumn toadstool Coprinus cinereus.

Tuesday, 8 September 2009

Snakeman, Butterflyman, Zsolt Balint and Joel La Rocque

For a little while now, I've been experimenting with e-zines: redrafting old articles and writing fresh ones for publication- mostly on

A few days ago, I came across this anecdotal article ( snake expert Joel La Rocque on his life collecting and studying snakes. I hope to have an interview with him soon. I will post a link or details [here] when it is available. In the meantime, I'd like to recommend that article on

I am also working on a series of interviews with entomologists- the first of these- with Hungarian biologist Dr Zsolt Balint- a world expert on lycaenid butterflies- will be published in a week or two- I will add the address [here-] once the article becomes live. [16th Sept-article now live- here]

Sunday, 6 September 2009

Cheering-up lizard- Jackson's Chameleon

This wonderful image of Jackson's chameleon was supplied to wikipedia by Benjamint444

The picture shows an animal from Melbourne Zoo and I've only ever seen this creature in an exotic pet shop. In that case, it had bright orange "horns", resembling 3 prehistoric carrots on its weird-yet-strangely-beautiful face.

This lizard may look like a dinosaur, but next week's cheering up animal really is one... watch this space....

Friday, 4 September 2009

Quote of the Week- Alan Turing- The Future

"We can only see a short distance ahead, but we can see plenty there that needs to be done."- Alan Turing ( 23/6/1912- 7/6/1954)

Wednesday, 2 September 2009

Ask a particle physicist with Dr Jeanne Wilson

Some time ago, I posed several questions about particle physics and radioactivity on this blog (now removed). I am happy to say that I have had my questions answered, courtesy of Dr Jeanne Wilson.

Dr Wilson is a former lecturer in physics at Oriel College Oxford and begins a lectureship Queen Mary, University of London next year. She studied physics at Sheffield and Oxford Universities in the UK and specialises in neutrino physics.
You can find a brief outline of her research here -

Jeanne kindly answered 3 questions for me. One of these is reproduced below- the answers to the other two will be available online shortly. These questions and answers are to be the first of a series of articles called "Ask an Expert",where I will ask experts in a range of fields for simple answers to fundamental and difficult questions about life, the laws of nature and the world in general.

I will modify this post to include a link [here] once the full article is available. In the meantime, here is question 1

VN) I wondered why alpha particles are the largest form of radiation? Are larger particles theoretically possible but only occur with a very, very, very long half life or at much higher or lower energy levels than in the universe as we experience it?
JW) Alpha particles are actually helium nuclei – they are made up of two protons and two neutrons, a stable particle. Radioactive decay occurs because the process of emitting the radiation releases energy leaving products in a more stable configuration than what you started with. You start with a nucleus with some intrinsic energy (as Einstein’s famous equation tells us – energy is related to mass) and you end up with a new nucleus and an alpha particle which together have a lower intrinsic energy. However, for this to happen you must negotiate the “energy barrier” provided by the force that holds nuclei together. Energy to step over this barrier could be provided by a external process such as a collision with another particle, but in the case of spontaneous radioactive decay the barrier is not stepped over, but tunnelled through. This phenomenon is called “quantum tunnelling” and is due to the wave-like behaviour of particles. In quantum physics, the wave describes the probability of a particle being in a certain location with a certain energy. If the barrier is narrow enough, the wavefunction extends to the other side of the barrier and there is a small possibility that the alpha will escape from the nucleus.

In principle, you could release something larger than an alpha particle but then the energy barrier is much larger and therefore quantum tunnelling is much less likely. This process is a form of radioactive decay, called spontaneous fission, and can only occur for very heavy nuclei.

-Many thanks to Dr Jeanne Wilson.

Echidna picture

There are some interesting wildlife and animal pictures online here-

I particularly like the second one- an echidna- it's rare to see a picture of an echidna close-up like this

Tuesday, 1 September 2009


This blog has become a little "cutsie" and zoological of late, so I'd like to redress the balance with something more physical and geographical. This picture of ice formations in a lake in Iceland, as seen from the air is by my friend Eduardo Izquierdo

This image is from Eduardo's photostream on flickr. His excellent photostream is primarily arty, rather than zoological or scientific; you can find it here-