A butterfly puzzle


i-d588e542b62fc1a9fcf63c21cc6d8a96-dimorphic_swallowtail.jpg

A reader sent in a question asking me to explain this: a swallowtail wings with different color patterns. Has anybody seen anything like this before? Got any explanations?

My first thought was that it was a genetic mosaic. A mitotic error in early development can lead to one wing primordium carrying a mutant allele, and the other carrying a wild-type form. At metamorphosis, the differences would become visible. It could be a defect that knocks out one pigment on pale wing, or since swallowtails can show sexual and seasonal dimorphism, it could be a change that switches on or off a male/female pattern, or an early summer/late summer pattern. Alternatively (and probably less likely), since seasonal morphs are switched by environmental conditions, this could have been a pupa in a very odd place that got different signals on the two sides.

If you’ve got a better idea, pass it on in the comments.

Comments

  1. Hank Fox says

    I’ve seen a couple of lobsters in the “oddity” news in the past year that have a sharp dividing line down their center, with different colors on the two sides of that line.

    I guess I assumed that a bilaterally symmetrical organism could vary from the first egg cell division. At the two-cell stage, why couldn’t one of the cells suffer a slight switch and produce slightly different characteristics? Maybe most of the changes would be lethal, but considering that in insects the population would be in the billions, if a non-lethal version of the event can happen at all, it’s almost inevitable that it WOULD happen.

    And … have I read something about, um, fraternal twinning, in which the two twins stick together at some very early stage of development, and develop as a single individual with bilateral symmetry, but with variant characteristics on both sides of the symmetry line?

  2. says

    I knew a girl in high school who had one blue eye and one brown. She’d had an eye injury as a child that briefly caused one eye to lose fluid. On recovery, the injured eye had lost its pigmentation cells, so it was blue.

    I won’t say that is what happened here, but a developmental injury is always possible, and it from the looks of the photo, all that seems to have happened is a loss of pigmentation, so something like that might have occurred.

  3. says

    Assuming the photo hasn’t been altered, it does indeed look like the eastern tiger swallowtail, Papilio glaucus, with the left wings of the dark female morph and the right wings of the normal color morph. The right-side wings seem to have very little blue for a female — wonder if it’s not only a gynandromorph, but a double color morph? (Of course, it’s hard to see the coloration on the right hindwing because of the angle.)

    There are some photos of this species at this site:

    http://www.duke.edu/~jspippen/butterflies/easterntigerswallowtail.htm

  4. says

    Regarding the original genetic mosaic hypothesis, would that explain one of my own peculiarities that I’ve always wondered about? I’ve got this little albino patch on my ankle, about two or three square inches. It’s even got white hairs there. As far as I can remember, I’ve never had any special injury there, and it’s always been there. Genetic mosaic sounds like it’s pretty much exactly what I’d long suspected, but it’s kind of nice to have a name for it now.
    Is it the most likely explanation, though? Any thoughts?

  5. says

    God did it, in that moment when he should have been winning that game for my favorite sports team, while He was transitioning between sides in the latest war.

    I lied. I don’t have a favorite sports team.

  6. craig says

    “Regarding the original genetic mosaic hypothesis, would that explain one of my own peculiarities that I’ve always wondered about? I’ve got this little albino patch on my ankle, about two or three square inches. It’s even got white hairs there. As far as I can remember, I’ve never had any special injury there, and it’s always been there. Genetic mosaic sounds like it’s pretty much exactly what I’d long suspected, but it’s kind of nice to have a name for it now.
    Is it the most likely explanation, though? Any thoughts?”

    I remember reading something where a man says that his hair was a mixture of his mother’s and his father’s… he had the light, fine hair of his mother interspersed with the dark, coarse hair of his father.

    When he reached about the same age at which his father had gone bald, he lost the dark, coarse hair, and retained his “mother’s” hair. I dunno if that sort of thing is possible or even makes any sense… but it’s odd.

    In my beard, I have fine reddish hairs that remind me of my mother’s side of the family, and some jet black, wire-brush type hairs that I like to think come from my dad.

    Then there’s this one mutant follicle that puts out thick brittle strands of straw that have no give and snap right off.

    Weird.

  7. says

    There was a second photo posted:
    http://www.flickr.com/photos/moonbird/216308917/in/photostream/

    The blue color is iridescent, so it’s not going to be totally evident unless pinned or photo’d under ideal conditions. It also seems to match many of the (non-yellow) females in your (Julie’s) link and it matches very closely the swallowtail in the original Gynandromorph! link – though male on the right side, differing with the Gynandromorph! link’s coincidence.

  8. Mike Huben says

    The Cornell insect collection has a gynandromorph mutillid wasp that also is very contrasty: the male side is short haired red, and the female side is long haired white. Mutillid males are normally winged, and females apterous; this specimen is entirely apterous.

  9. Diego says

    “Butterflies can’t hybridize with each other, can they?”

    Actually hybridization is not uncommon and there has been a lot of work for instance on Heliconius spp. and their hybrid zones.

    I agree with the gynandromorph diagnosis. Cool!

  10. SEF says

    Before even seeing the comments here, I was going to say that my butterfly/moth and insect books are full of examples like that! Except of course they’ve been deliberately drawn that way to show both of upper/lower or male/female in the same illustration. How convenient of some butterflies to save people the trouble. :-D

  11. TAW says

    The butterfly in the picture is obviously a gynandromorph, and if you look at the flowers it is also pretty obvious that the picture WAS probably edited. I don’t think the actual butterfly is fake though, just that the person went overboard with saturation, which can also explain why the blue in the female half is more prominent.

    have I read something about, um, fraternal twinning, in which the two twins stick together at some very early stage of development, and develop as a single individual with bilateral symmetry, but with variant characteristics on both sides of the symmetry line?

    yeah, chimeras. I saw a show on the discovery health channel, and they said some people have been born that are half white and half black, and showed some pictures of someone’s belly that had a checkerboard pattern of black and white (actually I think the checkerboard pattern was only on one side… I can’t really remember). It was an interesting show about this woman who for some reason got genetically tested, along with her children, and they told her they weren’t her children. long story short, she had a lot of trouble because of it, and after a while it turned out that her reproductive organs had a different genetic makeup (it was of the twin she swallowed up, LOL) than the rest of her cells did. Crazy stuff.

    I wanted to post a site with a ton of pictures of unusual butterflies (including gynandromorphs), but I can’t find it so I’ll just post this page with one- http://www.insectcompany.com/silkmoth/kwcmannana.htm (that site has a ton of awesome pictures of awesome moths btw)

  12. says

    Very neat, assuming it’s not a nefarious photoshopping.

    Eastern tiger swallowtails do come in two distinct color morphs, just like the left and right sides of that speciment. It would be nice to see the body, which also parallels the color morphs pattern, from what I’ve seen. So the genetic potential exists to produce this thing.

    In quite a few plants there’s something called twin spots – where mitotic crossovers occur under certain conditions, like cold. If the plant is heterozygous for a virescence, then the mitotic crossing over can produce on leaves a clonal area is yellow, next to a clonal area of green.

    If such a mitotic crossover occurred very early in development of a heterozygous color morph it might result in something like that.

  13. JohnnieCanuck says

    It’s official now PZ. You are the source to be consulted whenever a biological explanation is needed. Ten legs, eight, six, what’s the difference?

    It’s a remex in your cap!

  14. djlactin says

    On the topic of mitotic errors early on in development… In highschool I knew 2 sisters who were identical twins, and who would have been completely indistinguishable except that one had black hair and the other had white hair. (Not just brown and blonde: jet black and snow white.)

    I can only speculate that the coloration locus (I know it’s not so simple!) got miscopied (mitotic crossing-over) at the first cell division so that one daughter cell got a double copy and the other got none. I wonder what she would have looked like if the cells had not separated to make twins.

  15. Hank Fox says

    I’ve got this little albino patch on my ankle, about two or three square inches.

    I knew a guy years ago who had several unpigmented fingers and a patch on his wrist. It was some sort of minor hereditary trait, as I recall, that runs in Mediterranean bloodlines.

  16. says

    Hmm. No Mediterranean in me at all, as far as I know, and I don’t look the least bit Mediterranean, either. But I guess there might be alternatives to mosaicism, then.

    The butterfly in the picture is obviously a gynandromorph, and if you look at the flowers it is also pretty obvious that the picture WAS probably edited. I don’t think the actual butterfly is fake though, just that the person went overboard with saturation, which can also explain why the blue in the female half is more prominent.

    I really don’t think so. It does mention that the picture was taken with a camera phone, and a lot of those don’t deal with bright colours like that very well. That’s probably why some cameras qua cameras have a “foliage” setting for taking pictures (like mine). That’s probably plenty enough reason for it to look so very magenta (which, note, is the opposite colour in RGB from the predominant green, so it was probably trying to balance the green).

    Ten legs, eight, six, what’s the difference?

    Eight legs good, six legs bad!

  17. lo says

    yep, PEV is highly unlikely due to the seeming symetry. I think PZ pointed it out pretty well.

    BTW: Awesome. PS: I don`t think environmental circumstances could explain this symetric behaviour, that really seems to me like a genotypical cause. What could account for such symetry most likely are defects in the embyrogensis, and that is therefore most likely a mitotic defect at an early stage in embryogenesis. A meiotic defect couldn`t account in very rare cases for this symmetry.

    As for photoshop, so what it is then an attempted “simulation”, but science is science. There is nothing that wouldn`t permit the discussion of hypothetical causalities as well, in fact these are the forefront of science.

  18. lo says

    Of course there is also a logica explanation: the readers brother is running a clandestine pharmaceutical company, called pfizer in the ten square meter shack, nearby and induced RNAi in the left wing by either UV, temperature or any external environment that would trigger an interferrence with the gene products coding for the chromophores in the left wing and over time epistasis could set in so that an underlying pattern could becom visible.

    In fact his brother is thus on the frontier of the current state of the art. And the likelyhood of such a scenario is comparable with creationism, not only in mathematical chance but also in illiterate logic.

  19. lo says

    @Alan: Shame on you, you got it all wrong “God did it. No other explanation is possible.”

    God did it…..so far so good.
    No other explanation is permissible….think about the future, children are getting harder and harder to impress with some biblical crap that can be summed pretty much up in a 24hour television session.
    You need a stringent and forceful hand in the breeding of your kids so they do under no way revert to the pleasures that a logic mind can provide. Nurture over nature.

    Any sect works just like that, otherwise they would fall apart at the first doubt being uttered by some moronic “non-having-been-exploited-enough”.

  20. says

    I’d like to thank badthing and all above contributors for an awesome discussion. I’m the person who spotted the butterfly, and I was about 100feet frommy “real” camera… so the best thing to do at that time was to grab the cell. I really wish I had the other camera with me. I’ve never quite had an experience like seeing this butterfly yesterday. I knew at the time that we were dealing with some kind of oddball genetic crapshoot, so I’m grateful that it’s all been explained so eloquently above. Cheers!

  21. says

    Oh, and there was absolutely no editing of the photo in any way. Again, it’s a cell phone pic (Sony Erisson Z500a) with a rather poor camera. I still have the pics on the phone and would be happy to send them to someone here from the phone to verify.

  22. says

    Good move just using the camera on hand. Tigers can move fast and are easily spooked. Oh to have been a young 4Her with a net that day.

  23. JLem says

    open mouth, insert foot – just read about the gynandromorph stuff – my bad. sorry :(

  24. suezboo says

    Thank you Matthew for the link. Even I, the non-scientist around here, understood that. Fascinating stuff.

  25. Edgar says

    Very cool pic, i have seen before gynandromorphs on sexually dimorphic Papillonidae and Pieridae, and many times the intersexual individual had each side of body bearing the color morph of each sex….i wonder, why that neat division and why the sides? something to do with a link between the genes expressing bilateral symmetry and the sexual chromosomes? Really intriguing….