Denim and Tweed

On my iPod: Too Beautiful to Live

noreply@blogger.com (Jeremy) — Tue, 08 Dec 2009 23:07:00 +0000

I'm moving back into a labwork-intensive schedule at the moment, which means that I'm burning through podcasts like nobody's business. Fortunately, I've recently been sucked into the orbit of Too Beautiful to Live, the online incarnation of Luke Burbank's daily talk/music/newsish show. I only found TBTL after it lived up to its its name by getting dropped from the air by Seattle-area radio station KIRO.

Photo by bonacheladas.

Luke and his co-conspirators Jen "Flash" Andrews and Sean DeTorre put together an amalgam of music, pop-culture sound cues, news commentary, and whatever else happens to drift through Luke's head at the moment of recording. Topics range from the current status of the Large Hadron Collider to Alec Baldwin's self-esteem issues; one recent episode revolved around plumbing issues in the Burbank residence.* It's weird and silly and oddly compelling, and it works great in the background while I'm racking pipette tips.**

Which sounds like damning with faint praise, now that I re-read it, but really isn't. I mean, Studio 360 doesn't usually make that particular cut. Anyway, you should totally subscribe.

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* The appropriateness of which subject matter was discussed in today's episode, which was basically a recorded conversation between Luke and his girlfriend on a drive to down to Portland, and which achieved an almost "30 Rock"-grade degree of meta.

** Except for that one occasion when I had to dive across the lab to hit the volume control and kill Jen's Swedish Chef impression just as my (Swedish) dissertation advisor walked in the door.

This week in science blogging

noreply@blogger.com (Jeremy) — Fri, 04 Dec 2009 16:05:00 +0000

I'd like to try something new and see if it sticks -- a weekly post briefly noting a handful of items from the scientific blogosphere I've noticed in the past week. Here goes:

Photo by ehpien.

NeuroDojo: Chickadees grow new brain cells while caching food -- but they grow more in the wild than they do in captivity.
Dechronization: Mitochondrial DNA is not as good for evolutionary and ecological genetics as was once thought. It doesn't even evolve in a nice, clocklike fashion!
The EEB & flow: Plant communities have a lot going on underground.
Conservation Maven: Exotic giant tortoises seem to make pretty good replacements for extinct native giant tortoises. (Of course, it's hard to imagine introduced giant tortoises ever running amok in a new habitat.)
EcoTone: Loss of top predatory fish can spur algae blooms.

Evolving antibacterial therapies

noreply@blogger.com (Jeremy) — Wed, 02 Dec 2009 19:31:00 +0000

On Slate, Brian Palmer says we need better tactics, not better antibiotics, to combat drug-resistant bacteria. But the new "tactics" he describes are, basically, new drugs:

In vitro studies have shown that chemicals like ascorbic acid shut down the movement of antibiotic resistance between cells. (Right now it's effective only at concentrations that a person couldn't tolerate, but it's a start.) Because almost all antibiotic resistance relies on genetic transfer, this technique might be the solution we've been seeking since the very first colony of bacteria solved penicillin in 1944.

Drugs that combat gene transfer between bacteria probably would slow the spread of new antibiotic-resistance genes. Until bacteria evolve ways to transfer genes in spite of anti-transfer drugs, that is.

A genuinely new approach to circumvent antibiotic resistance will require actually thinking about the evolutionary consequences of therapy -- and creating natural selection that eliminates the damage done by bacteria without also creating a fitness advantage for resistance to the therapy. That's tricky, to say the least, but it's not impossible. Such an approach has been outlined to control disease-carrying mosquitoes, for instance.

For yucca moths, does (flower) size matter?

noreply@blogger.com (Jeremy) — Wed, 02 Dec 2009 15:05:00 +0000

In a paper just released online at Molecuar Ecology ahead of publication, genetic tests on moth larvae provide the latest piece to the puzzle of why there are two kinds of Joshua tree -- because the tree's pollinators need to match its flowers [PDF].

I've written extensively about the interaction between Joshua tree and its pollinators. Like all yuccas, Joshua tree is pollinated only by yucca moths. Female yucca moths collect pollen in special mouthparts and deliberately apply it to a yucca flower after laying eggs inside it. When the eggs hatch, the moth larvae eat some of the seeds inside the developing fruit. Yuccas prevent their pollinators from laying too many eggs by selectively killing flowers too badly damaged by egg-laying [$-a].

TOP: The two forms of Joshua tree (western type on left, eastern on right). BOTTOM: Scaled comparison of moth body sizes and tree pistils. To lay eggs in a flower, moths must drill from near the top of the pistil to the positions marked by dotted lines. Photo by jby, Illustration from Smith et al.(2010), figure 1.

This last element of the interaction may have had significant consequences for Joshua trees' evolutionary history. Joshua trees are pollinated by two different species of moths, which occur in different parts of the tree's range: the larger Tegeticula synthetica in the west, and the smaller T. antithetica in the east. Joshua trees pollinated by the two different moth species are themselves different, both in their overall shape, and in the shape of their flowers' pistils -- specifically, the length of the route that a moth must drill to lay her eggs [PDF].

How does this difference in flower shape affect Joshua tree pollination? If a larger moth attempts to lay eggs in a smaller flower, it may be do more damage to the flower than the "native" pollinator would, triggering the tree to kill the flower. On the other hand, smaller T. antithetica might be able to lay eggs in a larger western-type flower without this risk. If this is the case, moths probably can't pollinate western trees with eastern pollen, but they might be able to do the reverse.

Such one-way pollen transfer between the two Joshua tree types could produce a population genetic pattern called "chloroplast capture." Joshua tree pollen doesn't contain the full genetic code of the tree that produces it -- it lacks the genes contained in the chloroplast, the cellular structure that conducts photosynthesis, because pollen grains typically don't have chloroplasts. The DNA in the cellular nuclei of newly-formed seeds is a mixture of nuclear DNA (nucDNA) from a pollen grain and from one of their "maternal" parent's ovules, but they get all their chloroplasts, and chloroplast DNA (cpDNA), from the ovule. If moths carry pollen from eastern trees to western trees, then the seeds produced would contain western cpDNA, but also some eastern nucDNA.

Asymmetric pollen transfer can lead to eastern-type trees with western-type chloroplasts. Figure 2 from Smith et al.(2010).

This is what we've found in Joshua tree populations near the region where the two tree types and their pollinators come into contact. At these sites, trees look like the eastern type (meaning they likely have eastern nucDNA, though we haven't tested that yet) but have cpDNA that matches nearby populations of western-type trees [PDF].

The genetic pattern is only suggestive of one-way pollen transfer between the two Joshua tree types, though. We haven't yet tracked the movement of moths directly, or estimated whether they actually are less successful when laying eggs on the wrong tree type. The newly-published study provides exactly these data. My colleague Chris Smith placed glue traps on Joshua tree flowers at the contact zone to estimate how often adult moths of each pollinator species visited each type of tree in the mixed population. Adult moths were more likely to be trapped on their "native" trees, though they did show up on the other type sometimes.

A yucca moth larva emerges from a Joshua tree fruit in the lab. Photo by jby.

Chris and I then collected fresh fruit from trees in the contact zone, and caught yucca moth larvae as they chewed their way out. Chris and another coauthor, Chris Drummond, then identified the species of each larva based on their genetics (the two pollinators look very similar at that stage) -- and in our sample, the pattern of specificity was even stronger than that in the adults. The larger moth species, T. synthetica, never emerged from fruits of the small-flowered eastern trees. The vast majority of larvae of the smaller T. antithetica were also found inside their "native" tree's fruit -- but a handful did emerge from large-flowered western trees.

This mechanism could create the genetic pattern we see in Joshua tree populations. Larger T. synthetica doesn't seem to lay eggs in (or pollinate) small-flowered eastern trees, but smaller T. antithetica can occasionally lay eggs in (and pollinate) large-flowered western trees. This should create asymmetric gene flow, with pollen moving from eastern trees to western trees, but not the reverse. The two Joshua tree types may not yet be reproductively isolated, separate species -- but we won't know for sure without looking at the plants' nuclear DNA. As it happens, I'm working on that right now.

References

Godsoe, W.K.W., Yoder, J.B., Smith, C.I., & Pellmyr, O. (2008). Coevolution and divergence in the Joshua tree/yucca moth mutualism The American Naturalist, 171 (6), 816-823 DOI: 10.1086/587757

Marr, D., & Pellmyr, O. (2003). Effect of pollinator-inflicted ovule damage on floral abscission in the yucca-yucca moth mutualism: the role of mechanical and chemical factors Oecologia, 136 (2), 236-243 DOI: 10.1007/s00442-003-1279-3

Smith, C.I., Godsoe, W.K.W., Tank, S., Yoder, J.B., & Pellmyr, O. (2008). Distinguishing coevolution from covicariance in an obligate pollination mutualism: Asynchronous divergence in Joshua tree and its pollinators. Evolution, 62 (10), 2676-87 DOI: 10.1111/j.1558-5646.2008.00500.x

Smith, C.I., Drummond, C., Godsoe, W.K.W., Yoder, J.B., & Pellmyr, O. (2010). Host specificity and reproductive success of yucca moths (Tegeticula spp. Lepidoptera: Prodoxidae) mirror patterns of gene flow between host plant varieties of the Joshua tree (Yucca brevifolia: Agavaceae). Molecular Ecology DOI: 10.1111/j.1365-294X.2009.04428.x

Sins of omission

noreply@blogger.com (Jeremy) — Wed, 02 Dec 2009 08:28:00 +0000

I can't help but think this is going to strain Rick Warren's warm, personal friendship with Melissa Ethridge.

Via Slog. Yesterday's Fresh Air also had a great (by which I mean alternately appalling and rage-inducing) interview with Jeff Sharlet. My reaction: more or less as before. Also, thank God (or whoever) for Fred Clark.

"The Origin," 150 years old today

noreply@blogger.com (Jeremy) — Tue, 24 Nov 2009 08:05:00 +0000

Charles Darwin's groundbreaking work, The Origin of Species, was published 24 November, 1859, 150 years ago today. This makes a rather neat bookend to the Darwin Bicentenary, the year of events commemorating the 200th anniversary of Darwin's birth on 12 February, 1809. I'm going to be lazy and simply link to everything I wrote back concerning that earlier anniversary.

Oh, and serendipitously, today is also the anniversary of the discovery of Lucy in 1974. I saw her in person (behind glass) on a trip to Seattle during last year's fall break, which was pretty cool.

Photo by CharlesFred.

Aphid-tending ants cull the sick from the herd

noreply@blogger.com (Jeremy) — Mon, 23 Nov 2009 14:05:00 +0000

Just released online at Biology Letters: aphid-tending ants have been observed to selectively remove sick members of their "herd" [$-a].

Most aphid species produce some sort of sweet honeydew as waste while feeding on their host plants; ant-attended aphid species use this honeydew to attract ants. In many cases, the ants "milk" the aphids by stroking them to prompt release of the honeydew. While exploiting a colony of aphids, ants defend it as a food resource, protecting the aphids from predators. Aphid species that commonly rely on ant protection often lack defensive adaptations [$-a] found on species that don't interact with ants.

Ants tend aphids on a milkweed plant. Photo by dmills727.

Niesen et al. report the results of experiments performed ants attending colonies of milkweed aphids, Aphis asclepiadis, which are susceptible to a fungal pathogen that can wipe out aphid colonies in a matter of days. In two experiments, they introduced aphids into the ant-attended colonies, and tracked what the ants did to them. They found that

Ants were more likely to remove the corpses of fungus-killed aphids than either the corpses of aphids killed by freezing or introduced live aphids; and
Ants were more likely to remove live aphids contaminated with fungal spores (conidia) than live aphids without spores.

The authors speculate that this behavior is a re-application of ants' treatment of their own sick and dead within the colony. It seems clear that it should have benefits to both ants and aphids in this new context, slowing or preventing the spread of the fungus within an aphid colony. This benefit isn't directly tested by Nielsen et al., but such an experiment is a logical next step.

Reference

Nielsen, C., Agrawal, A., & Hajek, A. (2009). Ants defend aphids against lethal disease Biology Letters DOI: 10.1098/rsbl.2009.0743

Way, M. (1963). Mutualism between ants and honeydew-producing Homoptera. Ann. Rev. Entomology, 8 (1), 307-44 DOI: 10.1146/annurev.en.08.010163.001515

"Sheeeeit!"

noreply@blogger.com (Jeremy) — Sun, 22 Nov 2009 18:26:00 +0000

In the spirit of Kh(ax)n:

Google search results "Sh(ex)it!" for x = 1 to 30. Graph by jby.

I was inspired by that highlight reel from The Wire that's been going around the internet. (Caution: here be multiple and baroque uses of the f- and n-words, brief violence, and deep cynicism.)

And now, back to work.

The brood of vipers

noreply@blogger.com (Jeremy) — Fri, 20 Nov 2009 20:05:00 +0000

NY Times:

Citing the Rev. Dr. Martin Luther King Jr.’s call to civil disobedience, 145 evangelical, Roman Catholic and Orthodox Christian leaders have signed a declaration saying they will not cooperate with laws that they say could be used to compel their institutions to participate in abortions, or to bless or in any way recognize same-sex couples.
...
They say they also want to speak to younger Christians who have become engaged in issues like climate change and global poverty, and who are more accepting of homosexuality than their elders. They say they want to remind them that abortion, homosexuality and religious freedom are still paramount issues.

This, of course, is on the heels of the threat by the Roman Catholic Archdiocese of Washington, D.C. to discontinue charitable work if the city council passes a law prohibiting discrimination on the basis of sexual orientation.

Photo by jikido-san.

Christianity was founded on stories of a man who preached sacrifice of self to the needs of others, went drinking with prostitutes and other social outcasts, and was executed as a common criminal by the government. The figure of Jesus as described in the Christian scriptures is, to me, an ideal I can only hope to emulate. Yet many of the people who take his name for their moral identity -- and the loudest, most vehement and visible of those who do -- would evidently react with disgust if they met their Lord on the street, and condemn his teachings as un-American if they actually understood them.

I wanted to write something more scathing than that. But I'm just tired. I'm going to hand the mic over to that guy they keep claiming to follow.

Woe to you, teachers of the law and Pharisees, you hypocrites! You shut the kingdom of heaven in men's faces. You yourselves do not enter, nor will you let those enter who are trying to.
...
Woe to you, teachers of the law and Pharisees, you hypocrites! You give a tenth of your spices — mint, dill and cummin. But you have neglected the more important matters of the law — justice, mercy and faithfulness. You should have practiced the latter, without neglecting the former.
...
Woe to you, teachers of the law and Pharisees, you hypocrites! You are like whitewashed tombs, which look beautiful on the outside but on the inside are full of dead men's bones and everything unclean. In the same way, on the outside you appear to people as righteous but on the inside you are full of hypocrisy and wickedness.
...
You snakes! You brood of vipers! How will you escape being condemned to hell?
(Matthew, chaper 23, New International Version.)

Cost of killing nest-mates offset by benefits of killing nest-mates

noreply@blogger.com (Jeremy) — Fri, 20 Nov 2009 14:05:00 +0000

Among birds, brood parasites are the ultimate freeloaders -- species like the common cuckoo and the brown-headed cowbird lay their eggs in other birds' nests, leaving the host to raise the parasite chicks at the expense of its own. But while brood parasitism is easy on the parents, it isn't so easy on their chicks, as a study recently published in PLoS ONE suggests.

A reed warbler feeds a common cuckoo chick. Photo from WikiMedia Commons.

A brood parasitic chick faces two challenges. The first is to avoid being recognized by its adoptive parents and ejected from the nest; the second is to win parental attention in competition with their adoptive nest-mates. The first challenge may be partially met by the evolution of eggshells that match host eggshells; and brood parasite parents may also help by keeping watch on the host nest so they can punsish hosts who eject introduced eggs. (This punishment behavior has been described as an "avian mafia [$-a].")

In competition with their adoptive nest-mates, though, parasitic chicks are on their own. If the host's own eggs hatch, the host has more mouths to feed and less time to spend on the parasitic chick. On the other hand, a brood parasitic mother can't kick out the host's eggs at the time she leaves her own egg with the host, because the host may abandon a nest that contains only a single unfamiliar-looking egg. This leaves it to freshly-hatched brood parasite chicks to do the heavy lifting involved in ejecting their host's eggs themselves.

A common cuckoo chick pushes one of its host's eggs out of the nest. Detail of figure 1 from Anderson et al. (2009).

Egg eviction looks like hard work -- the chicks attempt it while they're not much bigger than the eggs. Anderson et al. investigated the cost of all this adoptive-siblicidal effort by manipulating reed warbler nests that had been parasitized by common cuckoos,* taking away the hosts' eggs in experimental nests, and comparing the growth of cuckoo chicks in those nests to that of chicks in unmanipulated nests, who had to do the evicting themselves.

They found that there is a cost to eviction effort: during the period of development when they would be doing all they could to push eggs out of the nest, cuckoo chicks grew faster when they didn't have eggs to push. But they didn't grow much faster, and by the time they were ready to leave the nest, the advantage had disappeared. Anderson et al. take this to mean that the cost of eviction is "recoverable" through the benefits of increased parental attention later on. I would add that it points out how important your choice of time frame can be when investigating how traits or behaviors affect organisms' evolutionary fitness -- sometimes a cost paid at one point in development is an investment toward later benefits.

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*The common cuckoo is the species first known to parasitize other birds' nests, and its name is the linguistic source of the term "cuckold."

References

Anderson, M., Moskát, C., Bán, M., Grim, T., Cassey, P., & Hauber, M. (2009). Egg eviction imposes a recoverable cost of virulence in chicks of a brood parasite. PLoS ONE, 4 (11) DOI: 10.1371/journal.pone.0007725

Hoover, J., & Robinson, S. (2007). Retaliatory mafia behavior by a parasitic cowbird favors host acceptance of parasitic eggs. Proc. Nat. Acad. Sci. USA, 104 (11), 4479-83 DOI: 10.1073/pnas.0609710104

Lahti, D. (2005). Evolution of bird eggs in the absence of cuckoo parasitism. Proceedings of the National Academy of Sciences, 102 (50), 18057-62 DOI: 10.1073/pnas.0508930102

Soler, M., Soler, J., Martinez, J., & Moller, A. (1995). Magpie host manipulation by great spotted cuckoos: Evidence for an avian mafia? Evolution, 49 (4), 770-5 DOI: 10.2307/2410329

Hey, PNAS?

noreply@blogger.com (Jeremy) — Tue, 17 Nov 2009 21:03:00 +0000

Hey, Proceedings of the National Academy of Sciences? (Can I call you PNAS? Thanks.) You know what really drives me crazy, as a scientist and a blogger, PNAS? Internationally-recognized journals that release scientific studies to the press before they make them available online.

Why does this make me crazy? I'm glad you asked, PNAS. It makes me crazy because sometimes I read something as batshit absurd as this gem from Wired Science:

No exact rule exists for deciding when a group of animals constitutes a separate species. That question “is rarely if ever asked,” as speciation isn’t something that scientists have been fortunate enough to watch at the precise moment of divergence ... [emphasis mine]

(Which statement is like claiming that physicists rarely ask about gravity.) And when I read something like this I'd really like to be able to go and see whether that's actually in the peer-reviewed article in question, or if it just materialized in the course of the sausage-making that is popular science journalism.

But, apparently, PNAS, you're more interested in having your results butchered by people who think biologists don't ask questions about speciation than you are in having them read by, you know, biologists. You'll forgive me, I hope, if I take that a little bit personally.

Joshua trees at LiveScience

noreply@blogger.com (Jeremy) — Fri, 13 Nov 2009 18:15:00 +0000

Over at LiveScience, my collaborator Chris Smith describes the research we've done so far on the interaction between Joshua trees and their pollinators:

First, the match between the Joshua tree flowers and the moths' ovipositors suggested that coevolution might have molded the relationship between the plant and the pollinator. Second, because the plants are completely dependent on the moths for reproduction, the differences in the flowers might have caused Joshua trees to split into two different species.

Yucca brevifolia in Tikaboo Valley, Nevada. Photo by jby.

Pollination before flowers

noreply@blogger.com (Jeremy) — Mon, 09 Nov 2009 16:05:00 +0000

Which came first, the pollinator or the pollinated? An article in this week's Science suggests that a diverse group of insects may have been drinking nectar and pollinating plants millions of years before the appearance of modern flowering plants [$-a].

Panorpis communis, a modern scorpionfly species, and a sketch of ancient, pollinating scorpionflies. Photo by JR Guillaumin; sketch from Ollerton and Coulthard (2009).

Prior to the origins of modern flowering plants, or angiosperms, in the early-middle Cretaceous period, most of the diversity of land plants were gymnosperms. These plants are characterized by "naked seeds" -- reproductive organs exposed to the air, where the wind can catch pollen and carry it from one plant to fertilize the ovules of another. In a world dominated by gymnosperms, the thinking used to be, animal pollinators were mostly unnecessary.

The new paper by Ren et al. challenges this idea with the description of a set of fossilized scorpionflies, all of which have strikingly long probosces that are clearly suited to sucking up liquid. The earliest of these fossils are from the Jurassic, tens of millions of years before the flowering plants began to diversify. In modern insects, sucking mouthparts like the ones described are associated with two kinds of feeding: drinking pollen, and drinking blood. To determine which was most likely in this case, Ren et al. performed energy-dispersive spectroscopy on the best-preserved fossil, and found no sign of the elevated levels of iron in the proboscis that would result from the residue of blood meals. This suggests that the scorpionflies were drinking nectar, or something like it.

Nectar has one major function in plants: to attract insects. Ant-protected plants reward their ants with nectar, and flowering plants use nectar to lure animal pollinators close enough to pick up or drop off pollen. If these ancient scorpionflies were, in fact, living on nectar, Ren et al. reason they were probably pollinating contemporary plants, which were all gymnosperms. The authors identify a diverse list of candidate host plants, including seed ferns and a relative of the modern ginkgo, whose reproductive structures were (1) too well-sheltered for efficient wind pollination or (2) included tubular structures similar to those that modern plants use to guide nectar-feeding pollinators. Finally, the authors point out, many modern gymnosperms produce "ovular secretions" that are very similar to the nectar produced by angiosperms.

As a neontologist, I'm often amazed how much can be told from million-years-old fossils -- who knew there was a way to test for residual blood in a fossilized proboscis? At the same time, Ren et al. connect some mighty scattered dots to build their hypothesis. The real clincher is that it seems mighty unlikely that animal pollination would be rare in a world that already has both flying insects and pollen-producing plants. Animal pollination is much more efficient than wind pollination, and if there's one constant in evolutionary history, it's that living things rarely miss an opportunity like that.

References

Ollerton, J., & Coulthard, E. (2009). Evolution of animal pollination. Science, 326 (5954), 808-9 DOI: 10.1126/science.1181154

Ren, D., Labandeira, C., Santiago-Blay, J., Rasnitsyn, A., Shih, C., Bashkuev, A., Logan, M., Hotton, C., & Dilcher, D. (2009). A probable pollination mode before angiosperms: Eurasian, long-proboscid scorpionflies. Science, 326 (5954), 840-7 DOI: 10.1126/science.1178338

Invasive species not so bad?

noreply@blogger.com (Jeremy) — Sat, 07 Nov 2009 19:46:00 +0000

Over on Slate, Rebecca Tuhus-Dubrow says some conservation biologists are starting to question the importance of preventing species invasions:

Certainly, they say, non-native plants and critters can be terribly destructive—the tree-killing gypsy moth comes to mind. Yet natives such as the Southern Pine Beetle can cause similar harm. The effects of exotics on biodiversity are mixed. Their entry into a region may reduce indigenous populations, but they're not likely to cause any extinctions (at least on continents and in oceans—lakes and islands are more vulnerable). Since the arrival of Europeans in the New World, hundreds of imports have flourished in their new environments.

Tuhus-Dubrow cites the case of Tamarisk in the U.S. Southwest -- an aggressive introduced shrub that has also ended up providing important nesting sites for the endangered southwestern willow flycatcher.

The fact of the matter is that human-introduced species can eventually integrate into an ecological community; once they do it's hard to get them out, and problematic as to whether it's a good idea. In Australia, dingoes helped extirpate many other large predators when they were introduced by the first humans to arrive on that continent -- and now they're critical to controlling other, later-introduced mammal species.

(Thanks to Ephraim Zimmerman for point this one out to me!)

Invasive pest, or critical flycatcher habitat? Maybe both. Photo by Anita363.

Defense, or Social Security?

noreply@blogger.com (Jeremy) — Thu, 05 Nov 2009 19:06:00 +0000

Mike Konczal considers the effect of breaking Defense Department spending out as a separate line item on pay stub tax witholding statements, alongside Social Security and Medicare. If citizens saw a number for military alongside social spending, they might make more informed choices about the relative values of each.

How much of your two weeks work cycle would you like to spend working to keep a global military hegemony going? I’d probably want to clock it out around my first coffee break on Monday (which is fairly early), but that’s me.

Some pacifists withhold a portion (or all) of their Federal taxes in protest against military spending, and there's even a campaign to let people opt out of funding the military on their tax forms. Maybe Konczal's idea would be a good alternative?

"France's answer to James Bond"

noreply@blogger.com (Jeremy) — Wed, 04 Nov 2009 07:02:00 +0000

Shades of Clouseau, but this still looks like I'd enjoy it way too much.

DVD on Amazon

Carnival of Evolution #17 at Adaptive Complexity

noreply@blogger.com (Jeremy) — Tue, 03 Nov 2009 18:43:00 +0000

Over at Adaptive Complexity, Michael White has just compiled the 17th monthly Carnival of Evolution. Marking the 150th anniversary of the publication of The Origin of Species (November, 1859), Michael structures submitted posts into a "virtual voyage of the Beagle." Topics range from the sexual habits of our ape-like ancestors* to a highly optimistic study predicting that the frequency of the creationist meme in the United States will drop to 0% by 2050.

* Which habits might, I think, explain why we never invite them round to tea.

Berry Go Round #21 at Beetles in the Bush

noreply@blogger.com (Jeremy) — Mon, 02 Nov 2009 18:20:00 +0000

Ted MacRae has a fine round-up* for the 21st monthly Berry Go Round, the bontanical blog carnival. And he notes that BGR needs a badge. Must ... resist ... urge ... to spend afternoon futzing with Inkscape.

Photo by jby.

*Including a set of nested footnotes that would make David Foster Wallace blush.

I want to teach this course

noreply@blogger.com (Jeremy) — Fri, 30 Oct 2009 17:29:00 +0000

Via io9: BIOL 103, "Biology in Science Fiction", at Kenyon College. Sure, the lesson on tribbles is probably just about density-dependent population growth. But it's a lesson on tribbles.

Endless forms: Oral sex by fruit bats

noreply@blogger.com (Jeremy) — Thu, 29 Oct 2009 18:02:00 +0000

One of those scientific papers that seems to have been written with the blogosphere in mind: biologists have just published records of fellatio by the fruit bat Cynopterus sphinx. Apparently C. sphinx females are pretty flexible -- they lick their mate's penis during copulation, which evidently induces him to stay in longer (see the graph below, with drawing). The authors offer a handful of non-mutually-exclusive hypotheses for the adaptive benefit of the behavior, ranging from lubrication to increased fertilization efficiency. The full text is available for free at PLoS ONE, if you're up for some hot-and-heavy behavioral observations.

Graph from Tan et al. (2009), Figure 3.

Update: In a more in-depth post over at Boing-Boing, Maggie Koerth-Baker wonders why there needs to be an adaptive purpose for a pleasurable behavior (there doesn't, as far as I'm concerned), and points out that there's also a video in the supporting information. Which video has some totally unscientific background music.

Reference

Tan, M., Jones, G., Zhu, G., Ye, J., Hong, T., Zhou, S., Zhang, S., & Zhang, L. (2009). Fellatio by fruit bats prolongs copulation time PLoS ONE, 4 (10) DOI: 10.1371/journal.pone.0007595

How to synchronize flowering without really trying

noreply@blogger.com (Jeremy) — Mon, 26 Oct 2009 16:05:00 +0000

One way plants can gain an advantage in their dealings with pollinators, seed dispersers, or herbivores is to act collectively. For instance, when oak trees husband their resources for an extra-big crop of acorns every few years instead of spreading them out, acorn-eating rodents are overwhelmed by the bumper crop, and more likely to miss some, or even forget some of the nuts they cache. These benefits of synchronized mass seed production, or "masting," are straightforward, but how it happens is less clear. A paper in the latest issue of Ecology Letters has an answer -- synchronization happens accidentally [$-a].

Bumper acorn crops ensure that squirrels miss a few. Photo by douglas.earl.

When Dan Janzen first described masting as an adaptation in plants' coevolution with seed predators, he proposed that "an internal physiological system" [$-a] acted as a timer between masting events, with masting ultimately triggered by weather conditions. However, mathematical models have suggested a different possibility, the "resource-budget hypothesis:" that masting synchronization arises through an interaction of resource and pollen limitation [$-a].

Resource limitation works in concert with pollen limitation by catching plants at two stages of the seed-production process. First, if the resources required for seed production are more than can be accumulated in a single year, or if the availability of resources varies from year to year, then some years will be spent building up reserves instead of producing flowers. When reserves are built up, seed production is limited by the availability of pollen to fertilize flowers. Plants that flower when most of the rest of the population doesn't will fail to set much seed, so they'll have reserves to make seeds in the next year. This doesn't require Janzen's "internal physiological system" for the plants to synchronize, although such a system might evolve to reduce the likelihood of wasting resources by flowering out of synch.

The new paper tests this model in populations of a western U.S. wildflower, Astralagus scaphoides, which flowers at high frequency every alternate year. The authors prevented seed production in the plants by removing their flowers, either in a "press" of three years in a row or in a single "pulse" during one high-flowering year. The plants' response to these treatments would reveal the role of resource and pollen limitation in synchronizing seed production.

If resource depletion after fruit set prevents reproduction in successive years, we predicted that 'press' plants would ﬂower more than control plants every year, as they were never allowed to set fruit. We predicted that 'pulse' plants would ﬂower again in 2006, but not set fruit due to density-dependent pollen limitation in a low-ﬂowering year.

The authors also measured the sugars stored in the roots of plants collected before and after flowering in a high-flowering year.

Seed predator in action. Photo by tombream07.

The resource-budget hypothesis worked. Plants prevented from setting seed were forced out of synch with the rest of the population. "Pulse" plants flowered the year after treatment, but because few other plants did, they received little pollen and set little seed. They then had resources to flower yet another year, with the rest of the population this time, and set much more seed, depleting their reserves and bringing them back into synch. "Press" plants continued to flower at high rates each year, as long as they were prevented from setting any seed. Sugar levels built up in the tested roots during non-flowering years, and dropped after high-flowering years.

So masting arises as an emergent result of two limitations acting on plants -- the resources needed to make seed, and good access to pollen. A couple of simple rules lead, undirected, to an ordered system that affects entire natural communities.

References

Crone, E., Miller, E., & Sala, A. (2009). How do plants know when other plants are flowering? Resource depletion, pollen limitation and mast-seeding in a perennial wildflower. Ecology Letters, 12 (11), 1119-26 DOI: 10.1111/j.1461-0248.2009.01365.x

Janzen, D. (1971). Seed predation by animals Ann. Rev. Ecol. Syst., 2 (1), 465-92 DOI: 10.1146/annurev.es.02.110171.002341

Janzen, D. (1976). Why bamboos wait so long to flower Ann. Rev. Ecol. Syst., 7 (1), 347-91 DOI: 10.1146/annurev.es.07.110176.002023

Satake, A., & Iwasa, Y. (2000). Pollen coupling of forest trees: Forming synchronized and periodic reproduction out of chaos. J. Theoretical Biol., 203 (2), 63-84 DOI: 10.1006/jtbi.1999.1066

Someone's on the ball

noreply@blogger.com (Jeremy) — Mon, 26 Oct 2009 05:14:00 +0000

The website for Evolution2010 is already online! I really like the logo. The site design looks familiar, and good for the organizers for not wasting time to re-evolve the camera eye, say I. Portland is going to be a great location, I think -- my experience is that Evolution meetings are largely remembered by the quality of beer available, which should be hard to get wrong in that town.

Image from Evolution2010.

An important distinction

noreply@blogger.com (Jeremy) — Thu, 22 Oct 2009 21:20:00 +0000

Courtesy Slacktivist:

Here I would remind us, again, of Wendell Berry's distinction between religion and superstition. Religion, Berry said, is belief in something which cannot be disproved. Superstition, on the other hand, is belief in something that has been disproved. The former can be reasonable, the latter cannot. For all of Bill Maher's railing against religion as "mere superstition," it seems he doesn't understand either of those ideas. His latest anti-vaccine, anti-medicine, anti-science crusade is superstitious nonsense. It's religulous.

The first church of taking offense

noreply@blogger.com (Jeremy) — Tue, 20 Oct 2009 00:38:00 +0000

Heard about R. Crumb's comic-book adaptation of Genesis? The Slog passes this along from the Daily Telegraph:

"It is turning the Bible into titillation," said Mike Judge, of the Christian Institute, a religious think-tank. "It seems wholly inappropriate for what is essentially God's rescue plan for mankind.

"If you are going to publish your own version of the Bible it must be done with a great deal of sensitivity. The Bible is a very important text to many many people and should be treated with the respect it deserves."

Thing is, Crumb's adaptation is an entirely straight-faced illustration of the text. (Check out NPR's excerpt, if you want to see for yourself.) So, yes, Adam and Eve are naked, and Lot has incestuous (and unwilling) sex with his daughters. But these are straight out of the text! That's right: a Christian "think-tank" is objecting to the very concept of illustrating the Bible. Slacktivist is right, in spades.

Fearmongering for good?

noreply@blogger.com (Jeremy) — Mon, 19 Oct 2009 21:10:00 +0000

Medical thriller specialist Robin Cook outlines the plot of a book about the catastrophe resulting from recombinant influenza, in the hope that such a book would spur preparedness efforts:

Governments and individuals will do desperate things, some rational and others not so, like deploying the military to try to close borders or using firearms to keep possibly infected strangers at bay. Hospitals will be overwhelmed at first and later forced to lock their doors. To avoid interpersonal contact, people will hole up in their homes, causing government offices, schools, and businesses to close. Many public officials will be forced to quarantine themselves from a diseased population and retreat to undisclosed locations, which will only fuel the public panic. Riot police in biohazard suits (if there are even enough to go around) will increasingly be called upon to beat back waves of sick, scared, and helpless civilians, desperate for food, water, and medicine.

Tom Clancy seems to inspire a lot of our homeland security policy (though less so under the present Administration) -- why shouldn't Cook have a go at public health planning? Personally, I find the pandemic 'flu threat more probable than terrorists armed with exploding water bottles.