Here is the press release:

An international collaborative study to map the genome of a South American butterfly has identified the secret behind its mimetic nature.

The genome sequence of the Postman butterfly, Heliconius melpomene, was used as a reference to study species that live together in the Peruvian Amazon. Several of these share bright wing patterns in order to reinforce a warning signal that they are bad to eat – dissuading predators from attack.

Sequence data showed that those species with similar wing patterns shared a similar genetic signal, precisely in those narrow regions of the genome responsible for controlling patterns. This is a result of hybrid exchange of genes between three co-mimic species, which has allowed them to copy each other’s wing patterns.

Dr Chris Jiggins of the University of Cambridge said, “These butterflies, in order to better survive in the wild, have taken successful survival techniques from other butterflies and have incorporated them into their own genetic code. This is significant as it has occurred in a natural adaptive radiation, suggesting an important role for hybrids in the origins of biodiversity.”

The phenomenon, known as adaptive introgression, involves different species sharing genetic material and has been considered very rare, especially in animals. Although many species can interbreed in the wild, the resulting hybrids are often infertile and considered an evolutionary dead-end. However, occasionally hybrids might introduce useful genetic material that can help populations adapt to changing conditions. This source of novelty might be more effective than having to wait for a mutation to occur in order to yield a similar result. In the case of butterflies, the effects can be clearly seen on their wings.

Dr Kanchon Dasmahapatra, who worked with Professor James Mallet at University College London added, “What we show is that one butterfly species can gain its protective colour pattern genes ready-made from a different species by hybridizing (or interbreeding) with it. A much faster process than having to evolve one’s colour patterns from scratch.”

The butterfly genus Heliconius is found in the tropical and sub-tropical regions of the Americas, from the Amazon basin to Texas and has been studied by scientists since the Victorian era.

Dr Jiggins added: “The genus Heliconius has been the subject of evolutionary studies since Darwin’s time, and the original formulation of mimicry theory. We are especially interested in them because their convergent wing patterns offer an opportunity to study the repeatability of evolutionary change.”

The sequencing of a butterfly genome also offers some remarkable insights into the biology of these charismatic insects. Butterflies are thought to be more visual in their communication as compared to night-flying moths. Surprisingly, analysis carried out at the University of California by Adriana Briscoe showed that they have an even greater array of genes involved in chemical communication as compared to moths.

Owen McMillan of the Smithsonian Tropical Research Institute in Panama said: “We are accustomed to thinking of butterflies as brightly coloured, primarily visual insects, but the presence of such a rich array of olfactory receptors and chemosensory genes, suggests that smell and taste are also vital.”

The study heralds a new era in genome biology, in which genome sequencing has become available to small groups of researchers for their own organism of choice. In this case academics from 9 labs across the globe each contributed to a pool of funding that permitted the sequencing effort, without any major grant funding.

Dr Jiggins added, “I think it’s been a great privilege to work with all these people across the world, and especially our collaborators in Latin America, who are all equally excited about these butterflies.”

Heliconius among other butterflies in the Tate Gallery

http://www.guardian.co.uk/environment/2012/apr/18/damien-hirst-butterflies-weirdly-uplifting?fb=native&CMP=FBCNETTXT9038

However, this was a topic that my colleague Jim Mallet had been interested in for a long time, as a denizen of Central America and Colombia many years before. Therefore, he wrote in 2006 to Gerardo Lamas, renowned as the expert who “maneja de manera diríamos casi “brutal”, la sistemática de prácticamente todos los grupos de mariposas diurnas del Neotrópico.” Mallet received this reply (parts of Mallet’s original email to Lamas is below).

In our work we have since been using this nomenclature.

___________________________________________

Gerardo Lamas –> Jim Mallet 26 June 2006

Dear Jim,

Sorry for the delay in answering your mail of exactly a month ago,
but then there were lots of questions in it! (and did you get the
photocopies I asked for…?)

Anyway, here I’ll try to comment on your news and queries:

…

The erato subspecies found in Colombia are as follows:
- hydara (NE Panama, N Colombia)
- venus (SE Panama, W Colombia)
- cyrbia (SW Colombia)
- chestertonii (Cauca valley)
- colombina (Medellín area towards Muzo-Otanche) ["demophoon" of Brown]
- guarica (= euryas) (Magdalena valley)
- dignus (Putumayo area)
- lativitta (SE Colombia)
- reductimacula (SE Colombia)

H. e. cruentus is the subspecies found in W Mexico, W Guatemala and
El Salvador (i.e., the Pacific side); petiverana is found in the
Gulf side of Mexico, south to Nicaragua; demophoon goes from S
Nicaragua to W Panama. Demophoon and cruentus are more similar to
each other than either is to petiverana.

The melpomene subspecies found in Colombia are as follows:
- melpomene (NE Panama, N Colombia)
- vulcanus (W Colombia)
- new ssp. (Magdalena valley) [this is the "Neukirchen MS" ssp.; "euryas" of Brown]
- bellula (= mocoa Brower) (Putumayo)
- vicina (E Colombia)
- malleti (SE Colombia)

H. m. rosina occurs from Nicaragua to W Panama. The yellow-barred
form from the Magdalena valley (“ca. rosina” of Brown, equivalent to
erato colombina) doesn’t have a name either.

Hope the above is of some help.

Best,
Gerardo

Jim Mallet –> Gerardo Lamas 24 May 2006
I was recently asked a question about Colombian erato and melpomene names by Jean Francois [LeCrom, a Colombian entomologist of considerable note], and realize I don’t know the answer and also cannot deduce it from your checklist.

In Mexico, for Heliconius erato there are now two names which you have as valid subspecies — cruentus and petiverana. Are they both valid?

You have an erato name demophoon from Nicaragua, which is presumably the nearest thing to the Central American form from Costa Rica and Panama. But I guess the demophoon specimens probably have much narrower yellow hindwing bands, and are likely to look more like the Mexican things than Panama Costa Rica.

Does this use of demophoon mean the yellow barred, slightly iridescent form from near Muzo and Otanche in the Magdalena valley is unnamed? Or is it one of the other names you have scattered around from Colombia? In a way, this perhaps ought not to be called a subspecies at all, since it seems always polymorphic (Mauricio and I visited there). On the other hand, it probably represents a race that has been gobbled up by the hydara type in the rest of the Magdalena valley.

What is the “hydara type” from the rest of the Magdalena valley called? Is it now considered to be guarica instead of euryas? [N.B. Lamas found that the "euryas" type was actually a Heliconius erato form].

What is “colombina”?

You probably know that dignus is from the Putumayo in SE Colombia, and has a large mountain range and hundreds of km of pure hydara-like forms between it and the nearest other yellow-barred form near Muzo and Otanche to the N. Also the form of the yellow bar is very different — uniquely it is round-tipped, and not pointed.

For melpomene:

I assume rosina must be the central American yellow-barred form.

You probably know this but bellula is from SE Colombia, on the Eastern slopes of the Andes and shouldn’t be confused with the rosina types to the North and in the Magdalena valley. It has a good disjunction consisting of most of the southern and central Magdalena, and also the mountain range.

So what is the Muzo Otanche form with yellow bar (now polymorphic). Does it have a name?

What is the form said to exist in the Magdalena valley. Should we just use melpomene melpomene?

What does “ac) [n. ssp.] Neukirchen, MS” look like and where is it from?

All the best, Jim

Please volunteer if you would like to present a short talk. So far I suggest short talks by:
Simon B – BD candidate genes 1
Carolina – BD candidate genes 2
Kanchon – hybrid speciation in elevatus?
Annabel – numata wing patterns
Rob Jones – RNA-seq
Rainer – Melitaea genome
Ullasa – brief intro to Bicyclus
Simon M – Speciation Genomics
Gabriel J – tests for selection
Topics for discussion, with possible discussion leaders
Rainer/Ullasa – Comparative butterfly genomes
John Davey – Third gen sequencing
Dan Lawson – where to go with ENSEMBL, databasing etc from here

Accommodation:
Sun, Mon and Tuesday nights:
Rainer
Adriana Briscoe
Sunday and Monday nights:
Mark Blaxter and John Davey
Ben Elsworth
Mon and Tuesday nights:
Mathieu
Rob
Barbara

Also attending but not requiring accommodation:
Ullasa (Bicyclus Cambridge)
John Welch
Richard ff-C
Andrea Dowling
Annabel Whibley
Kanchon Dasmahapatra
Dan Lawson
William Palmer
Frank Jiggins
Steve Montgomery

Jiggins lab people:
Chris
Carolina
Simon M
Simon B
Krzystof K
Sohini
Rich W
Patricio
Martin
Gabriel Jamie
(Rich M and Nicola are in Ecuador)

Dear Dr. Eratosignis,

From a review of publications, we believe you might be interested in antibodies with computational homology to Heliconius erato. Aviva has compared the protein sequences associated with our catalog of over 37,000 antibodies to the gene sequence database of Heliconius erato to find matches.

The best method for us to select antibodies for you is if you could send us a gene or protein sequence of interest to you. If you would like to submit a sequence, please visit the following webpage:

Brian suggests ‘Giant H. erato FG hybrids maybe (DdSdsd)’. Any more suggestions regarding their genotype/species?

The trailer can be seen here on YouTube

Here are some links that give more details:
Science perspective article by Sean Carroll
Link to original article

The study focused on the Amazonian species Heliconius numata, which mimics several other butterfly species at a single site in the rainforest. One population of Heliconius numata can therefore feature many distinct wing colour patterns resembling those of other butterflies, such as the Monarch’s relatives Melinaea, which are unpalatable to birds. This acts as a disguise, protecting them against predators.

The researchers located and sequenced the chromosomal region responsible for the wing patterns in H. numata. The butterfly’s wing-pattern variation is controlled by a single region on a single chromosome, containing several genes which control the different elements of the pattern. Known as a ‘supergene’, this clustering allows genetic combinations that are favoured for their mimetic resemblance to be maintained, while preventing combinations that produce non-mimetic patterns from arising. Supergenes are responsible for a wide range of what we see in nature: from the shape of primrose flowers to the colour and pattern of snail shells.

The researchers found that three versions of the same chromosome coexist in this species, each version controlling distinct wing-pattern forms. This has resulted in butterflies that look completely different from one another, despite having the same DNA.

“We were blown away by what we found”, said Dr Mathieu Joron of the Muséum National d’Histoire Naturelle, who led the research. “These butterflies are the ‘transformers’ of the insect world. But instead of being able to turn from a car into a robot with the flick of switch, a single genetic switch allows these insects to morph into several different mimetic forms – it is amazing and the stuff of science fiction. Now we are starting to understand how this switch can have such a pervasive effect”

Professor Richard ffrench-Constant of the University of Exeter added: “This phenomenon has puzzled scientists for centuries – including Darwin himself. Indeed, it was the original observations of mimicry that helped frame the concept of natural selection. Now that we have the right tools we are able to understand the reason for this amazing transformation: by changing just one gene, the butterfly is able to fool its predators by mimicking a range of different butterflies that taste bad.”
This single supergene also appears important in melanism in other species, including moths. In April 2011, a team led by Liverpool University explained in the journal Science how the Peppered Moth developed its black wings in nineteenth-century Britain’s sooty industrial environment.
“This supergene region not only allows insects to mimic each other, as in Heliconius, but also to mimic the soot blackened background of the industrial revolution – it’s a gene that really packs an evolutionary punch,” added Professor Richard ffrench-Constant.

I have recently found that the search engine at darwin-online.org is not perfect. If you search for “helic” on the whole darwin-online.org site, you’ll draw a blank. I had then also forgotten something I had known for a long time: that Darwin did discuss Heliconius and other mimetic butterflies in the Descent of Man and Selection in Relation to Sex.

Darwin was trying to explain bright coloration, and birds and butterflies were among his main empirical examples. Bright colours in many butterflies are characteristic of males, and can be explained by sexual selection.

However, heliconians and danaines are more or less sexually monomorphic. So why are these butterflies brightly coloured? Warning colours and mimicry provide an alternative explanation of bright coloration not involved with sexual selection. See: http://darwin-online.org.uk/content/frameset?itemID=F944&viewtype=text&pageseq=1 and search for “helic”.

This is also where Darwin recounts how Wallace in the 1860s solved the problem for him of bright colours in caterpillars (which have no sex, and so couldn’t be sexually selected!). They were warningly coloured.