Passive aggression: Parasitic wasp larvae interfere with each other via their host's host plant

A large white butterfly caterpillar weaves a cocoon around the wasp larvae infesting its body. Photo by EntomoAgricola.

I'm embarrassed to admit that I've only just gotten around to picking up Carl Zimmer's book Parasite Rex. It's turned out to be a wonderful compendium of all the peculiar ways parasites evade, confound, and resist the defenses of their hosts. Some of the wildest cases Zimmer examines, though, are parasites that manipulate their hosts' behavior.

One grotesque and well-studied example is the wasp Cotesia glomerata. Female C. glomerata wasps inject their eggs into butterfly caterpillars, and when the eggs hatch, the wasp larvae eat the caterpillar from the inside, saving critical organs so the poor thing stays alive the whole time. Then, when the wasp larvae are ready to burrow out of the caterpillar and form pupae to complete their devlopment, they induce the half-dead caterpillar to spin a web around them and stand guard against predators. (In technical language, this life history makes the wasp a parasitoid, rather than a parasite.) Christie Wilcox has written up a fuller description of the whole grisly process, if you want more detail.

That sounds like a pretty incredible set of manipulations for one clutch of wormy-looking wasp larvae, but they're not all that Cotesia glomerata can do. New evidence published in Ecology Letters suggests that C. glomerata can somehow make the plants that its host caterpillar feeds on less hospitable [$a] to the larvae of another caterpillar-infesting wasp. In other words, the wasp larvae may manipulate not just their host, but their host's host.

Science online, preventative treatment edition

Nap time. Photo by bhermans.

• A few CCs of prevention. Antiretroviral treatment is 96 percent effective at preventing HIV transmission between partners.
• Humans as part of our own environment. Stopping the extinction crisis we're causing may require a new perspective.
• Another reason not to put your phone inside a hive. Cell phone signals may be bad for bees.
• As with all fitness measures, it depends on ecological context. Is there an evolutionary advantage to being right?
• Kill your alarm clock. Compared to the rest of the world, WEIRD* people have weird sleep habits, too.
• Feeding like a whale, millions of years before whales. The toothless ichthyosaur Shastasaurus probably sucked small prey into its mouth.

Like Denim and Tweed? Spread the word on Facebook!

* Western, Educated, Industrialized, Rich, and Democratic

Pesticides and parasites add up to an evolutionary Catch-22

When Daphnia evolve resistance to pesticides, they become more vulnerable to bacterial parasites. Photo by Chantal Wagner.

If you haven't read Joseph Heller's classic Catch-22, cancel your plans for next weekend and spend the time with a copy from the nearest library. It's a hilarious, bracingly bleak satire of military bureaucracy, as epitomized in the titular clause governing when bomber pilots can be grounded for reason of insanity:

There was only one catch and that was Catch-22, which specified that a concern for one's safety in the face of dangers that were real and immediate was the process of a rational mind. Orr was crazy and could be grounded. All he had to do was ask; and as soon as he did, he would no longer be crazy and would have to fly more missions.

Heller conceived Catch-22 as a product of malicious middle management, but a similar situation crops up in the natural world when living things are under natural selection from conditions that favor contradictory traits. Biologists most commonly call these tradeoffs.

Over the course of evolution, tradeoffs set up "choices" that natural selection must make—a population can adapt to one alternative set of conditions, or another, or settle on a middle ground. A trivial example is that elephants have long ago "chosen" not to fly (Dumbo notwithstanding) in the course of evolving large, un-aerodynamic bodies suitable for massive-scale herbivory. A more relevant example is a new finding that the evolution of pesticide resistance creates vulnerability to parasites [$a].

Diversity in Science Carnival, now with online submission form

To celebrate Pride Month 2011 (just eight shopping days left!), Denim and Tweed is hosting a relaunched Diversity in Science blog carnival, collecting online writing about lesbian, gay, bisexual, and transgender issues from across the science blogosphere. Alberto Roca of Minority Postdoc is leading the DiS relaunch, and he's just created a handy online submission form for the carnival.

So now sending in your posts—new for June or years old—is as easy as copying a permanent URL into the form (preferably in the "message" box) and signing it with your e-mail address. What are you waiting for? [Edited to add:] You have until Monday, 27 June to submit, so I can put the carnival online by the 30th!

Science online, on the road all week edition

Touching. Photo by WTL Photos.

• Phrase of the week: "mental hangover." Migraines are mysterious, but we understand even less about their aftermath, the postdrome.
• Sorry, Mom. Why do sons cost their mothers more than daughters, and how do those costs manifest?
• With a bingo card for educational fun! A comprehensive guide to debunking bullshit evolutionary psychology.
• Just like getting into Carnegie Hall. Blind people have more sensitive fingertips, but sighted people can make up the difference with practice.
• Avast! Branding strategies were employed by pirates, and by those who didn't care for them.
• This is all your fault, game theory. The Rapture may not make theological, scientific, or logical sense—but it may have a basis in game theory.

Like Denim and Tweed? Spread the word on Facebook.

This was the start of my week

Packing up. Photo by jby.

The rest of my week is going to consist of driving across two time zones, seeing my parents off on a flight further east with many thanks for their assistance in getting me across those aforementioned timezones, and intensive apartment hunting in not one but two new cities. So no new science post this week; we'll see how next week goes.

Science online, pompous circumstance edition

Finished! Photo via Boston Public Library.

Graduatin' tomorrow, movin' east next week. It's as though I've come to the end of some sort of long, strenuous, athletic activity ...

• Because it's there? Dave Munger wonders why anyone would run a marathon.
• Convergent evolution—in two different directions. The extinct marsupial predators known as thylacines may have had dog-like skulls, but their elbows suggest they hunted like cats.
• Where frequency meets ill-preparedness. The regions where a particular kind of natural disaster causes the most damage are not always the regions where it occurs most often.
• All the fun of opinion polling, with nasal swabs. Recruiting participants for even a small epidemiological study is logistically tricky.
• After olives, the goddess Athena invented wheat-free ambrosia. The history of gluten-related health issues stretches from ancient Greece to your neighborhood Whole Foods.
• Fossilized. Raindrops. It may be possible to reconstruct the density of the ancient atmosphere by measuring fossilized raindrops.
• Next up, Am Nat? The ecology journal Oikos recently launched a blog featuring "armchair ecology" on topics from the value of (judicious) hand-waving arguments to lichinivorous moths.

Video of the week, from the BBC: a time-lapse simulation of fetal face formation. Watch as ontogeny (kinda, sorta, okay not really) recapitulates phylogeny.



Like Denim and Tweed? Why not tell Facebook?

The Daily Show on the Minneapolis gay scene

Following up on The Advocate's declaration that Minneapolis (soon to be one of my two new hometowns), is the gayest city in America, a Daily Show investigation compares Minneapolis to the San Francisco to determine whether the new gay is Minnesota nice. I must admit, banana bread is more my speed, although I'm not so sure about patronizing Target.

Don't watch unless you don't mind and/or want to see Jason Jones in a, um, compromising position. Not just shopping at Target, either.

The Daily Show
Tags: Daily Show Full Episodes,Political Humor & Satire Blog,The Daily Show on Facebook

Via The Blotter.

Coming in June: The Diversity in Science Carnival relaunches for Pride Month

Updated, Friday 13 May: Added a suggested topic and a link to the "recent NAS report."

June is Pride Month in the U.S., and I'm proud to be joining Alberto Roca of Minority Postdoc to commemorate the month with a blog carnival. On 30 June, Denim and Tweed will host a new entry in the Diversity in Science blog carnival, collecting posts about sexual minorities in the sciences, the science of sexual minorities, and more. For Coming Out Day last October, Steve Silberman and Maggie Koerth-Baker did a fantastic job bringing together the stories of lesbian, gay, bisexual, and transgendered scientists and engineers—Alberto and I are hoping to build on and extend that theme.

GLBT folks and allies who work in the sciences or write about science are invited to submit new posts as well as relevant pieces from their archives. We don't have a Blog Carnivals submission page online yet (Alberto is working on reviving the DIS page), but you can send links with background information to me at the Denim and Tweed e-mail account—just put "Pride Month blog carnival" in the subject line. Please submit by Monday, 27 June to give me time to put together the carnival post.

When does a beneficial mutation fail to benefit?

Beneficial mutations, according to Hollywood, include the superpowered ability to make San Francisco Bay foggy. Photo via Comics Contiuum.

Every time a cell divides is an opportunity for mutation, creating new genetic variation that may be beneficial, may be harmful, or may make no difference at all. In sexually reproducing species, the fate of a useful new mutation is relatively straightforward. If it overcomes the vicissitudes of genetic drift, the mutation will spread through the population as recombination swaps it into different genetic backgrounds, so that on average the mutation spreads or disappears on its own merits.

In asexual species, though, things are less straightforward. This is because new mutations are stuck with the genetic backgrounds in which they first appear—whether they spread of disappear depends not only on the fitness benefits they might provide, but on how beneficial the variation in the rest of the genome is, too. A new beneficial mutation in an asexual population is like a race car driver who can't change cars—she might be an ace at the wheel, but if she's stuck in a Yugo, she's probably not going to win.

So what happens to a new beneficial mutation in an asexual population is largely dependent on random factors: genetic drift and mutation. That randomness means that in order to know how new useful mutations behave in general, the only robust solution is to watch lots of new useful mutations in lots of otherwise identical populations.

In other words, it's a question best approached using experimental evolution. That brings us to a study just released in advance of print by the journal Genetics, in which a team headed by Greg Lang uses some clever methods to track the origin and fate of beneficial mutations in yeast.

Hey, look at that

Google Translate knows Latin.

Science online, periodical feast edition

A periodical cicada from brood XII. Photo by JanetandPhil (Correction, 2 June 2011: replaced photo by James Jordan, which depicted the wrong cicada species).

• Still not as fast as on CSI. The lab work for genetic identification of, say, that terrorist mastermind you just killed, goes quicker than you might expect.
• Not named Uroptychus pinnochio because that name is taken already. A newly discovered lobster is distinguished by its prominent rostrum.
• Time to reinstate the noon-time martini. Is lunch in danger of extinction thanks to social anxieties?
• The case of the missing (bird) baby boom. You'd think that the emergence of huge swarms of periodic cicadas would be a boon for bird populations—but you'd be wrong.
• Born that way. "Lesbian" lizards (of the sort discussed here) have been bred in the lab from sexual parents.
• Maybe these were better bird food than cicadas? A two-inch long fossilized ant has been unearthed in Wyoming.

Like Denim and Tweed? Why not tell Facebook?

Help make it better for queer students at U of I

The Palouse in summer. Photo by jby.

Just as I'm wrapping up my time at the University of Idaho, the University's LGBTQA Office is starting up an important new initiative: an emergency fund for queer students who've been disowned by their parents.

Moscow, Idaho, isn't what you'd think of as a good place to come out of the closet—it's a tiny university town in the middle of lots and lots of farmland. But Moscow is disproportionately queer-friendly for its size, and many U of I students come from even smaller, more isolated, much more conservative towns in other parts of the state. For queer students coming from towns like that, Moscow is the first town they've ever lived in with a any kind of queer community, and the first chance they've ever had to explore and express their identities without fear of ostracism or worse.

Unfortunately, parents back in small, hyper-conservative Idaho towns are not necessarily supportive when a son or daughter comes to terms with a new sexual identity at university. Often that means strained relations buffered by a six-hour cross-state drive. Sometimes, though, it's meant that U of I students who come out to their parents—or who are outed—find themselves cut off financially in the middle of earning a degree.

Released from predators, guppies reshape themselves—and their environment

A (domestic) male guppy. Photo by gartenfreuden.

Consider a population of guppies living in the Aripo River in Trinidad. They have a happy existence, as far as guppies can be happy, but their lives are shaped by the constant threat of larger, predatory fish. The river runs clear over a colorful gravel bed, and guppies who stand out against that background are eaten quickly. Even guppies whose coloration helps them blend in have to be ready to make a break for it if a predator shows up. All in all, a guppy's chances of surviving to mate depends most on its ability to hide from bigger fish, and to swim quickly when it can't hide.

Then one fine day a biologist comes along, scoops up a couple hundred guppies, and moves them to a pool in a tributary of the river. The pool is separated from the mainstream by a series of waterfalls, so larger fish can't swim up—the guppies are now free from their most dangerous predators. They can be fruitful and multiply. In this new habitat, camouflage and evasive maneuvers don't matter so much. What does matter is finding enough food to make some babies in the midst of a whole bunch of other guppies who are also not particularly worried about predators.

John Endler started the experiment I've just described back in 1976 to see whether guppies' coloration helps them hide from predators [PDF]. The guppies he moved to a predator-free stream have continued to evolve, though, and three decades later, new studies are showing how release from predators changed the guppies—and how those changed guppies could be changing the living community around them.

Tipping your online science writers

Tip jar. Photo by burningkarma.

I woke up this morning to learn that Ed Yong liked my post about quasi-carnivorous plants so much that he's willing to pay for it. That is, Ed's included my post in his monthly collection of online science writing worthy of a sort of collective tip jar—he pledges £3 to each of the selected authors, and collects donations from his readers to divvy up amongst the authors at the end of the month. It's a cool initiative that's been underway for a couple months, so it's a mite embarrassing that I'm only mentioning it now that I've been included.

In any event, I'm pretty sure this marks the first time I've been paid for a piece of writing—certainly the first time I've been paid for a post to Denim and Tweed—and I'm honored to be included in a list alongside top-notch science writers like Brian Switek, Jonah Lehrer, and Maryn Mckenna. I strongly encourage you to read them all, and consider putting something in the tip jar.

Carnival of Evolution, May 2011

Carnival. Photo by Mastery of Maps.

What has two thumbs and forgot to submit to the Carnival of Evolution this month? This guy. But not to fear—lots of other great science writers remembered the deadline, and the new edition of the blog carnival collecting online writing about evolution and its implications is now online at Lab Rat's blog. Go check it out!