myrmecos

Breaking News: The First Ant Genomes

Camponotus floridanus & Harpegnathos saltator

The journal Science has just reported the first ant genome study. Well, the first ant genomes. A pair of them, from the Florida Carpenter Ant Camponotus floridanus and the Indian jumping ant Harpegnathos saltator, both study animals in the lab of Arizona State University’s Juergen Liebig.

Abstract: The organized societies of ants include short-lived worker castes displaying specialized behavior and morphology and long-lived queens dedicated to reproduction. We sequenced and compared the genomes of two socially divergent ant species: Camponotus floridanus and Harpegnathos saltator. Both genomes contained high amounts of CpG, despite the presence of DNA methylation, which in non-Hymenoptera correlates with CpG depletion. Comparison of gene expression in different castes identified up-regulation of telomerase and sirtuin deacetylases in longer-lived H. saltator reproductives, caste-specific expression of microRNAs and SMYD histone methyltransferases, and differential regulation of genes implicated in neuronal function and chemical communication. Our findings provide clues on the molecular differences between castes in these two ants and establish a new experimental model to study epigenetics in aging and behavior.

Below is a schematic from the paper that on a crude level depicts the overall similarity of the new genomes to previously published insect genomes (click to enlarge):

These genomes could be a great resource for myrmecologists. And I mean that: they could be. But they probably won’t.

As this project was funded by a private source (the Howard Hughes Medical Institute), the original data are only available to the scientists directly involved. This not only means that outsiders cannot independently verify the results, but that the utility of these genomes to the larger research community is actually pretty small. These genomes- in the short term at least- will serve the careers of a few scientists. And of course some of the findings that emerge from this group’s papers will enter the broad sphere of human knowledge.

But to most working ant biologists, today’s announcement is not as momentous as it may sound. The public genomes coming out shortly (disclaimer: I’ve had a very minor role in one of them) will be of considerably broader impact.

*update: YAGS

The Conference Art of Barrett Klein

Is your academic conference boring, lifeless, and lacking inspiration?

That’s too bad. You probably should have invited Barrett Klein.

Barrett is a recently-minted Ph.D. from UT Austin who studies social insects. But that’s not the subject of this post. Rather, Barrett has developed a habit of borrowing name tags from other conference attendees and adorning them with topical artwork while the symposia progress.

Over the course of a conference colorful name tags start appearing here and there, and soon everyone is asking about them and wondering when Barrett has time to make a custom tag. It reminds me of Dr. Suess’s Sneetches. Everyone wants stars upon thars…

Anyway, below the fold are some of Barrett’s tags from the IUSSI meeting earlier this month in Copenhagen.

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Answer to the Monday Night Mystery

What were those sonorous summer songs?

In spite of being “the toughest MNM yet,” several of you picked the correct answers. Five points each go to Scot for the scissor-grinder cicada Tibicen pruinosa, and to Ted MacRae for the jumping bush cricket Orocharis saltator.

An excellent resource for learning the singing insects of eastern North America is the Songs of Insects site. Lang Elliot and Wil Hershberger have assembled a library of clean recordings paired with sharp photographs- a real treasure for insect enthusiasts.

Cover Story: Is Kin Selection Dead?

My photo of two Formica nestmates accompanies the latest salvo in the long-standing argument over the roles of Kin Selection and Group Selection in the emergence of eusociality.

I disagree with the conclusion that kin selection has little to do with social evolution, but as I’m short on blogging time today I will spare you the details. For now.

A lady beetle pupates in time lapse…

…but the aphids steal the show:

As you may have noticed I’ve been experimenting recently with various forms of video. Time-lapse photography only requires a regular still camera, a tripod, and an interval timer, so it doesn’t need any video equipment save the software on the finishing end. The above clip is made from 1/2 second exposures taken every 4 seconds over a couple hours.

But time lapse is highly finicky in its own right. It wasn’t until after I viewed the video did I realize that the tripod wasn’t entirely stable (hence the occasional camera shake), and that I shouldn’t have left the camera on auto-white balance (hence the flickering). It’s a rather unforgiving medium, and I’ve still got plenty to learn.

Monday Night Mystery: The Sounds of Late Summer

Click to listen

At least two insects are audible in the sound clip linked above, recorded just ten minutes ago in my yard in Urbana, Illinois. What are they?

The first correct species name for each insect is worth 5 Myrmecos Points (TM).

As usual, the cumulative points winner for the month of August will win their choice of 1) any 8×10-sized print from my photo galleries, or 2) a guest post here at Myrmecos on a safe-for-work topic of their choosing.

Washboarding Bees

And now, another video from my back yard Myrmecos studios:

Our two hives are roughly equal in strength, but one of them fields a couple hundred worker bees ‘washboarding’ every afternoon on the front of the hive. It’s a distinctively mesmerizing behavior, and what’s especially remarkable about it is that no one knows what function washboarding serves. Honey bees are perhaps the most-studied insect of all time, and yet there is still a great deal to learn even about common bee behaviors.

Ants from the Grave of Thomas Say

Tapinoma sessile Say 1836

Among the first species that students of North American ants learn is Tapinoma sessile, the odorous house ant.

This small brown insect lives in nearly every temperate habitat across the continent. Sonoran desert washes? Check. Alpine meadows in the Sierra Nevada? Check. Wheat fields in Nebraska? Check. Long Island suburbs? Also. My kitchen? All over the place.

Tapinoma sessile was named by Thomas Say, a naturalist living in the utopian settlement of New Harmony, Indiana in the 1820s. Say is widely considered to be the father of American entomology, first discovering and describing more than a thousand of our familiar insects: the Colorado potato beetle, thief ant, cinch bug, several malaria mosquitoes, some cicadas, parasitic wasps, and so forth. Tapinoma sessile was among his final creations, published posthumously in 1836.

Scientific names of most species are stabilized by anchoring them- in a legal framework- to physical specimens kept in museums. These key name-bearing specimens are called types, and they are useful in resolving arguments concerning the validity of names, or whether a particular name ought apply to a particular population of organisms. As you might imagine, types are important. Without them taxonomists lose the connection between the names and the corresponding flesh-and-blood organisms.

Until recently, Tapinoma sessile has had no type specimen. Say’s collection was mostly lost in the years following his death in 1834. With it vanished any trace of the insects Say looked at when he penned his description of the ant. The odorous house ant has been taxonomically adrift ever since.

Where I am going with this? (more…)

Answer to the Monday Night Mystery

What was that magical mystery DNA?

A ten-point sweep to commentator Formicidae Fantasy, whose rapid series of answers was spot-on:

  1. It’s from Apis dorsata…

  2. And I believe that it determines sex, so that homogeneous individuals will be male.

  3. And apparently males produced this way get eaten before maturity!

That’s exactly right.

Here’s a BBC video of our favorite narrator hanging out (literally) with Apis dorsata: