#evol2010 day 4: In which the race is not always to the swift, and giving up on sex isn't a dead end

Updated, 2010.06.30: Publish in haste, revise at leisure. I've gone back and added some links to original papers mentioned in the talks, and a note on another talk I meant to include (the first in the list, now).
And again, 2010.07.02: Added a specific link to the EvoDevoGeno audiocast, and to Vincent Calcagno's professional page.


The final day of Evolution 2010 featured a fantastic series of talks in the ASN Young Investigators Symposium, and marked the premiere of the iEvoBio sister conference, which ran concurrently today. Perhaps not surprisingly, the #ievobio tag quickly outran the #evol2010 tag on Twitter.

I'm ending the conference with a final wrap-up audiocast with the crew from Evolution, Development, and Genomics, and then hopefully a quick run before the closing banquet.

A western bluebird arrives at its nest box. Photo by kevincole.

• Vincent Calcagno used adaptive dynamics models of a victim-exploiter coevolutionary relationship (think predator and prey, or host and parasite) to show that rapidly-evolving victims were not always able to escape their exploiters [$a].
• Joel McGlothlin demonstrated how testosterone's influence on dark-eyed junco males' aggressiveness and parental contributions produces alternate strategies for fitness [PDF]: either be a good father, or sire more chicks.
• Marc Johnson presented evidence that species of evening primrose which evolve asexual reproduction are less able to defend against herbivory [PDF], but also more likely to form new species.
• Renee Duckworth described how the availability of nesting sites—these days, usually human-made nest boxes—determines whether Western bluebirds are selected to move away from the site of their birth [PDF], and that female bluebirds can manipulate their sons' likelihood of doing so. She also demonstrated that bluebirds are exceptionally photogenic.

Primary literature referenced

Calcagno, V., Dubosclard, M., & de Mazancourt, C. (2010). Rapid exploiter‐victim coevolution: The race is not always to the swift. The American Naturalist DOI: 10.1086/653665

Duckworth, R., & Kruuk, L. (2009). Evolution of genetic integration between dispersal and colonization ability in a bird. Evolution, 63 (4), 968-77 DOI: 10.1111/j.1558-5646.2009.00625.x

Johnson, M., Smith, S., & Rausher, M. (2009). Plant sex and the evolution of plant defenses against herbivores. Proc. Nat. Acad. Sci. USA, 106 (43), 18079-84 DOI: 10.1073/pnas.0904695106

McGlothlin, J., Jawor, J., & Ketterson, E. (2007). Natural variation in a testosterone‐mediated trade‐off between mating effort and parental effort. The American Naturalist, 170 (6), 864-75 DOI: 10.1086/522838

#evol2010 day 3: In which butterflies self-medicate and Orr conjectures

How do you know it's getting to be the end of the Evolution 2010 meetings? Because I didn't get to this until this morning, in the back rows of the SSE symposium on evolutionary prediction. But the third day of the meetings were great, with cool natural history and a great address by SSE president H. Allen Orr.

And don't forget to check out the daily wrap-up audiocast over at Evolution, Development, and Genomics, which was just endorsed by none other than Carl Zimmer.

A monarch butterfly. Photo by mikebaird.

• Thierry Lefevre presented evidence that female monarch butterflies infected with a microbial parasite lay their eggs on host plants with more toxins that can fight the parasite.
• Susan Dudley presented new work on kin recognition in the small annual plant Cakile edentula, in which the plants grow less aggressively if planted next to close relatives.
• Ian Pearse presented evidence that introduced oak species were more likely to be attacked by a native herbivore if they were more closely related to native oak species.
• Finally, H. Allen Orr capped the day with an SSE presidential address that focused on what we know—and what we don't—about how reproductive isolation evolves and creates new species. Orr concluded with three conjectures:
  • Extrinsic postzygotic isolation is usually due to adaptation to ecological conditions,
  • Intrinsic postzygotic isolation is usually due to adaptation to the intrinsic environment within the genome, and
  • Prezygotic isolation is usually due to sexual selection.
  The idea, of course, is to collect the data to test these conjectures. But I'd say these make pretty good sense based on what we already know.

Edit, 2010.06.30: Swapped the original photo for one that actually depicts a monarch butterfly, as discussed in the comments (thanks, Julie!).

Primary literature referenced

Dudley, S., & File, A. (2007). Kin recognition in an annual plant. Biology Letters, 3 (4), 435-8 DOI: 10.1098/rsbl.2007.0232

#evol2010 day 2: In which sexes diverge and reptiles are disparate

In day two, Evolution 2010 is already feeling a mite overwhelming. I started the morning in the SSE symposium on speciation and the origin of dimorphism, then spent the rest of the day bouncing from talk to talk and preparing for my own presentation, which is tomorrow at 9:30. I'm going to bed early tonight, I think.

There's a new daily wrap-up podcast over at Evolution, Development, and Genomics, and, if you haven't been following the conference on Twitter, check hashtag #evol2010 or this list of twittering attendees I've compiled.

What's going on with snakes, anyway? Photo by Tambako the Jaguar.

• In the SSE symposium, Jenny Boughman and Dan Bolnick discussed ways in which the evolution of sexual dimorphism was like the evolution of different ecological specialists [PDF]—and how males and females evolving different ecological roles can counteract divergent selection acting on the population as a whole.
• In the same symposium, Marguerite Butler showed that correlated neutral evolution of male and female traits may have shaped the diversification of Anolis lizards, using OUCH, a statistical package for R [PDF] that Marguerite demonstrated at the seminar I just attended.
• Luke Harmon presented an impressive but not very conclusive exploration of morphological evolution in squamate reptiles. One insight: once a reptile loses its limbs, its head is free to evolve in new ways, but not always the same ways. Why? Good question.

Primary literature referenced

Bolnick, D. I. & Doebeli, M. (2003). Sexual dimorphism and adaptive speciation: Two sides of the same ecological coin. Evolution 57(11):2433-49 DOI: 10.1111/j.0014-3820.2003.tb01489.x.

Butler, M., & King, A. (2004). Phylogenetic comparative analysis: a modeling approach for adaptive evolution. The American Naturalist, 164 (6), 683-95 DOI: 10.1086/426002

#evol2010 day 1: In which chromosomes invert and sources sink

The first day at Evolution 2010 has been a great one. The location in Portland is proving to be great in stereotypical ways: great beer from Rogue Ales, conference t-shirts by American Apparel. There's pretty good chatter on Twitter this year under the hashtag #evol2010, and in a first for Evolution meeting coverage, there will be daily wrap-up audiocasts (in which I'll be participating) at the blog Evolution, Development, and Genomics.

Amusingly, we're sharing the Oregon Convention Center with a "Christian" homeschooling conference, but so far this has led to neither disruptions nor learning experiences.

Mimulus cardinalis. Photo by randomtruth.

Some highlights of the talks I've attended so far:

• Jeffrey Feder proposed a new means by which chromosomal inversions might evolve, via a period of allopatric population isolation that allows a locally adaptive inversion to spread, followed by secondary contact during which gene flow creates selective pressure to reduce recombination that could break up the inversion.
• Simone Des Roches presented new evidence that three lizard species, which have colonized a region of white sand in the New Mexican desert and subsequently evolved "blanched" coloration [PDF], are experiencing ecological release and density compensation. (Simone and her labmate Kayla Hardwick recently discussed their work in blog format.)
• Chelsea Berns demonstrated that, alone among North American temperate hummingbirds, Ruby-throated hummingbird males have differently-shaped bills from Ruby-throated females.
• Joel Sachs described the natural frequency and origins of rhizobial bacteria that "cheat" on their host plants.
• Sheina Sim described host shifts in the apple maggot fly, Rhagoletis pomonella: the fly originally shifted from its native host, hawthorn, to domestic apples [PDF] when they were introduced to North America—now the fly has been introduced to the Pacific Northwest via transport of apples, and some populations have shifted back to hawthorns.
• The American Society of Naturalists Vice Presidential symposium presented a large volume of work towards discovering the reasons for species' range boundaries, including great syntheses of population genetic and experimental data for the wildflowers Mimulus cardinalis and Clarkia xantiana—one emerging theme is the importance of the balance of gene flow from healthy populations in the center of ranges to poorly-adapted populations at the edges.

Update, 1950h: The first Evolution 2010 audiocast is now live for download here.

Primary literature referenced

Feder, J., Chilcote, C., & Bush, G. (1988). Genetic differentiation between sympatric host races of the apple maggot fly Rhagoletis pomonella. Nature, 336 (6194), 61-64 DOI: 10.1038/336061a0

Rosenblum, E. (2006). Convergent evolution and divergent selection: lizards at the White Sands ecotone. The American Naturalist, 167 (1), 1-15 DOI: 10.1086/498397

Science online, Portland-bound edition

Just two days after I get back to Moscow from that Santa Barbara, I'm off again to Portland, for Evolution 2010. As in previous years, I'll try to post daily notes about cool talks I see at the meeting, and maybe some photos of Portland, where the weather is allegedly going to be warm and sunny. In the meantime, here's what's been going on in the science blogosphere this week:

Never again? Photo by Vern and Skeet.

• Still gushing. Earlier this week, BP removed the containment cap on the Gulf of Mexico oil gusher following a mishap with an underwater robot, but it's back for now. Internal documents suggest that, early on in the disaster, BP knew a lot more oil was flowing than they told the federal government. Hydrology experts are considering how existing flow control structures might be able to use the Mississippi River itself to protect coastal wetlands from oil.
• Reconsider that sashimi. An environmentalist group is petitioning to protect bluefin tuna, which spawn in the Gulf of Mexico, under the Endangered Species Act. (NY Times)
• Meanwhile, in even longer-running fossil fuel disasters. In Pennsylvania coal country, underground mine fires burn unchecked. (SEED Magazine)
• Walk like a man. A newly-discovered fossil of Australopithecus afarensis—the same species as "Lucy"—has a ribcage more like a human's than an ape's, suggesting that it stood upright. (A Primate of Modern Aspect)
• Why did the moose cross the road? Larger mammals with broader home ranges and lower reproductive rates are at greater risk of becoming roadkill. (Conservation Maven)
• No word about preference for rock'n'roll, though. Attitudes about sex are better predictors of attitudes about drug use and religion than "abstract political ideologies." (Blag Hag)
• Wait, there's software to do that? You never know when the Methods section of an otherwise obscure paper is going to turn up something useful. (NeuroDojo)

And now, a video of aggregating ladybugs.

How I spent (the first weekend) of my summer not-quite-vacation

Phylogeny of the Prodoxidae, the family of the yucca moths, with a (very basic) reconstruction of pollinator life habits. Image by jby.

Late last night I made it back to Moscow from (mostly) sunny Santa Barbara, California, where I was lucky enough to attend a summer short course in phylogenetic comparative methods using R, sponsored by NESCent, hosted by NCEAS, and helmed by Luke Harmon and Mike Alfaro. I came into the seminar as a big fan of the programming language R already, and it was great to learn about a whole new range of tools available for the platform. It was even better to learn about those tools in a group of really smart colleagues, all of whom were thinking about how best to use R in their own projects. It was like a warm-up for the Evolution meetings, which start this Friday.

Like the meetings, one of the principal pleasures was learning about everyone else's study organisms, the best example being the wrinkle-faced bat, which has the strangest trait I think I've ever seen in a mammal: a bald face, and a "mask" of furry skin it can pull over said face. Flickr has photos! I'll put one below the fold in deference to the squeamish.

With conspecifics like these, who needs predators?

Update, 19 July 2011: More than a year after this study was published, some important objections have been made about very basic assumptions of the experiment presented. Also, I've fixed the first link the original article.

There's something special about islands. After moving to islands, plants adapted to rocky outcrops evolve to grow in rainforests and alpine meadows, and finches evolve to behave like woodpeckers. But why? Islands contain new food sources and habitats, they often lack predators, and they can provide more geographic barriers to generate reproductive isolation—to name just a few possibilities. A newly published ecological experiment now provides evidence that one group of island lizards diversfied because islands are crowded [$a].

There's something about islands. Photo by Storm Crypt.

Diversification on islands may be related to density compensation, the frequently-observed principle that islands often support fewer species than mainland sites of the same area, but contain more individuals of each species—that is, island populations are usually at higher density than their mainland counterparts [$a]. Density compensation seems to arise both from lack of predators on islands, and because island populations have fewer competitor species. This may mean that, compared to mainland populations, island populations are under weaker natural selection from other species, and stronger selection from competition with other members of their own species.

Science online, southward bound edition

I'll take the high road, you take the low road ... Photo by gwgs.

• Still gushing. The Deepwater Horizon well is still not contained. Wednesday BP agreed to set aside $20 billion for an independent reparations fund.
• Got 'em coming and going. Even if they escape being soaked in oil themselves, seabirds are at considerable risk of eating oil-soaked prey. (Deep Sea News)
• Me, I just turn left by default. Given a choice between a southern route and a northern route of equal length, people will choose the southern route—apparently because it feels easier. (Wired Science)
• Who doesn't want a view of the park? The conservation benefits of protected land can be offset if nearby real estate becomes popular. (Conservation Maven)
• This is why I'm not a neurologist. Remember all those papers based on fMRI brain scans? Yeah, apparently we've only just discovered what fMRI scans actually mean. (Neurotopia)
• Looking for an open alternative to MatLab? Try Python. (U+003F)
• What is "forty-two," Alex? IBM's next advance in artificial intelligence centers on teaching a supercomputer to answer "Jeopardy" questions. (NY Times)

This week's video from BBCEarth: David Attenborough says "boo" to a sloth.

Memo to Solid Rock Church, Monroe, Ohio:

When you rebuild the enormous Jesus-idol that just burned to the ground after being struck by lightening, it probably wouldn't make it any more sacrilegious if you add a couple of lightening rods.

The graven image, before it experienced the wrath of static electricity. Photo by DRust.

“It sent goosebumps through my whole body because I am a believer,” said Levi Walsh, 29. “Of all the things that could have been struck, I just think that that would be protected. ... It’s something that’s not supposed to happen, Jesus burning,” he said. “I had to see it with my own eyes.”

“I can’t believe Jesus was struck,” said his brother, who noted the giant Hustler Hollywood sign for the adult store across the street was untouched. “It’s the last thing I expected to happen.”

Whether jostled by the incident, or ready to call out zingers, all agreed the statue is what makes that stretch of I-75 in front of the church special.

Via Dan Savage, who correctly identifies the violation of the second commandment; and Slacktivist, who implicates Zeus.

And here we have Idaho

So let's review how my soon-to-be-Alma Mater, the University of Idaho, has earned national media coverage in the last couple months:

• U of I scientists discover the allegedly giant Palouse earthworm is actually about eight inches long.
• This American Life helps a stutter-prone U of I student send a message to the jerks at the local Pizza Pipeline. In a rerun. From 2002.*

The campus water tower. Photo by jby.

-----------
* And TAL refers to the student as going to Idaho State, which is located not in Moscow, where the Pizza Pipeline is said to be (and there is one here), but in Pocatello, at the other end of the state. Which is confusing, and additionally vexing given that no one has bothered to correct the discrepancy since 2002.

Not just babble: Cooperating birds talk it through

For cooperation to work, everyone involved needs to know what the others are willing to contribute in order to decide what she will contribute. You might think that only humans can achieve that kind of back-and-forth negotiation, but a paper recently published online by Proceedings of the Royal Society suggests otherwise. In it, ornithologists decode the negotiations [$a] that allow sociable birds to share the task of watching for predators.

The southern pied babbler, Turdoides bicolor. Photo by Blake Matheson.

Pied babblers (Turdoides bicolor) are sociable South African songbirds, which live and forage for food in groups. During foraging, some adult babblers act as sentinels, perching above the ground to scan for predators, and alerting the rest of the foragers if any danger shows up. Sentinel behavior is cooperative—sentinels free the rest of the group to concentrate on feeding, but sentinels themselves cannot forage. The study's authors, Bell et al. hypothesized that sentinels might communicate how long they're willing to stand watch to the rest of the group, so as to prompt new birds to take up watch and given the current sentinels a break to feed.

Science online, phylogenetically distant edition

Louisiana Fish and Wildlife staff rescue an oil-coated pelican. Photo by The News Hour.

As of Thursday night, the Gulf of Mexico oil gusher is capped, but still gushing—and new reports suggest even more oil than previously thought has escaped. Plumes of oil are spreading under the surface of the Gulf. Reports from the American Birding Association are pessimistic at best. On the bright side, an environmental law expert told NPR earlier in the week that criminal prosecution arising from the spill will be "a slam dunk." Southern Fried Science has compiled the best online sources for oil spill news, including this salty primer on oil containment with booms. I'd add ProPublica's excellent coverage to the list—and you should go hear ProPublica's Abrahm Lustgarten tell Terry Gross about BP's dismal safety record in case you feel your outrage flag.

In non-catastrophic science news:

• Darwin was right. Again. Confirming a prediction made in The Origin of Species, a recent study shows that bacterial strains are better able to invade cultures of distantly-related strains than closely-related ones. (The EEB & flow)
• Surprising it's not higher, really. A survey of marine biology papers suggests that about 25 percent of literature citations are "inappropriate"—but apparently considers citing review articles "inappropriate." (Neurodojo)
• Because men are shallow, whatever our orientation. Gay men are 50 percent less likely to be obese than straight men; the reverse is true for women. (Slog)
• Really, it's a shame to waste so much neck. Contrary to the current prevailing thinking among paleontologists, at least one sauropod species seems to have used its long neck to reach high-up foliage. (Dinosaur Tracking)
• Somewhere in here is an episode of Star Trek. Unlike males, female jumping spiders will fight to the death in confrontations over territory—especially if they're almost ready to lay eggs. (EcoTone, Wired Science)
• Accidental complexity in the genetic code. Introns, snippets of non-protein-coding DNA interspersed within protein-coding DNA, may have originated as "selfish genes" in our bacterial ancestors. (Wired Science)

This week's video: BBC footage of aphids' peculiar lifestyle.

I need to rewatch Starship Troopers

At the AV Club, Scott Tobias describes in detail how the blockbuster space opera undermines militarism with its own tropes. He also picks up on something I haven't, embarrassingly enough:

In the scheme of Starship Troopers, it’s important that the actors be pretty and vacuous, and their characters’ romantic dilemmas of the most banal variety imaginable. Hence the casting of Van Dien and Richards in the lead roles, instead of Hollywood stars with more history and substance, who might have torpedoed the film with any hint of self-awareness. (Neil Patrick Harris, as a brainy military intelligence officer who struts around arrogantly in a Gestapo-like trenchcoat, is the only young cast member who seems in on the joke.) ... Their shallow conflicts give the film shape and direction, but it’s obvious Verhoeven and Neumeier find them petty and stupid. (One bizarre example: When Van Dien comes to blows with his romantic rival, [director Paul] Verhoeven mutes this grand melodramatic moment by flooding the soundtrack with the dreamy Mazzy Star single “Fade Into You.”)

The propaganda videos interspersed through Troopers are where Verhoeven really tips his hand—they undercut the whiz-bang sci-fi action with moments that should make any thoughtful person squirm. This one uses some imagery that, as Tobias points out, is amazingly prescient for a film made in 1997. (Caution: contains depiction of human-on-alien violence, bitter irony, and Neil Patrick Harris.)

Agora

I agree with PZ: this looks pretty good. Or else like two hours of dry speechifying punctuated by riot scenes staged by too few extras. I put the odds of "good" at about two in three.

The "Big Four," part IV: Migration

This post is the last in a special series about four fundamental forces in evolution: natural selection, mutation, genetic drift, and migration.

Edited 8 April 2011: Following some interesting comments from population geneticist Lou Jost, I've edited my characterization of the rule of thumb that one migrant per generation is generally enough to prevent populations from differentiating.

It's the little differences. I mean, they got the same shit over there that we got here, but it's just—it's just there it's a little different.
— Vincent, Pulp Fiction

Different places are different from each other. This is a truism bordering on tautology, but it also has real implications for the ways in which life evolves and diversifies. The specific differences between one environment and another shape how well living things can move between those environments, and what happens when they do—the evolutionary consequences of migration.

Canada geese on the wing. Photo by Brian Guest (giant rebus).

Individuals moving between populations can alter the evolution of those populations in a number of ways [$a]. Migration introduces traits from one population into another, making it a source of variation not unlike mutation. Migration can swamp out the effects of local natural selection, if enough migrants come from a population experiencing a different selective regime. Migration from a larger population to a smaller one can offset the loss of variation to genetic drift; but a small group of individuals migrating to an empty habitat can be strongly affected by drift. Depending on what species concept you prefer, migration between two populations is either what prevents them from becoming separate species, or what conclusively proves that they are the same species.

University of California system vs. Nature

Holy cow is right. In response to a threatened 400 percent increase in institutional subscription fees for 2011, the University of California system is threatening to boycott Nature and its sister journals [PDF].

... unless NPG [Nature Publishing Group] is willing to maintain our current licensing agreement, UC Faculty would ask the UC Libraries to suspend their online subscriptions entirely, and all UC Faculty would be strongly encouraged to:

• Decline to peer review manuscripts for journals from the Nature Publishing Group.
• Resign from Nature Publishing Group editorial and advisory boards.
• Cease to submit papers to the Nature Publishing Group.
• Refrain from advertising any open or new UC positions in Nature Publishing Group journals.
• Talk widely about Nature Publishing Group pricing tactics and business strategies with colleagues outside UC, and encourage sympathy actions such as those listed above.

UC scientists will still get Nature articles—but now via e-mail from colleagues with personal subscriptions or access through non-UC libraries—and NPG will make nothing on those transactions. Refusal of peer review services—free labor provided to journals as a sort of scientific civil duty—also seems like it could reasonably inconvenience NPG. The full text of the memo mentions a similar successful boycott of Elsevier and Cell Press back in 2003, so clearly withdrawing the collective scholarly involvement of the UC scientific community can make a journal publisher take notice.

"What are birds? We just don't know."

The British are still light-years ahead of us Yanks when it comes to deadpan silliness.



And yes, there's a whole series. I recommend Maths and Iron.

Science online, short work-week edition

Make mine a double. Photo by Ballistik Coffee Boy.

• Not as obvious as it seems. Computer modeling suggests that giraffes are much worse swimmers than other ungulates—which suggests that giraffe populations should be easily isolated by water barriers. (Tetrapod Zoology)
• Guess it's time for that second cup. Regular coffee drinkers need their morning dose of caffeine just to achieve the baseline alertness of non-coffee-drinkers. (Yahoo! News)
• Jet-setting dinos. New fossils show that ceratopsian dinosaurs (the group including Triceratops) had a wider range than previously thought, colonizing the landmass that would become modern Europe. (Smithsonian.com)
• No carbon-free lunches. A new analysis of plant communities' ability to absorb carbon dioxide suggests that managed landscapes like cropland may emit more of the greenhouse gas than they absorb. (Conservation Maven)
• They still haven't explained why Justin Bieber is so popular. As with biological evolution before it, the study of cultural evolution is advancing as scientists develop methods to directly experiment with cultural transmission. (A Replicated Typo)
• More bad news. Computer simulations suggest that the Gulf of Mexico oil spill, now in its sixth week, will probably spread to the Atlantic by the end of the year. (Wired Science)

Here's video of one scenario from the oil-in-the-Atlantic study.

Freeloading cuckoos force their hosts to diversify

Ashy-throated parrotbills have a problem every time breeding season rolls around: how do they know whether the eggs in their nests are their own, or those of the common cuckoo? A study recently released in PLoS ONE suggests that one population of parrotbills fights this brood parasitism by laying eggs of different colors.

Common cuckoos lay eggs that mimic those of the host birds they trick into raising cuckoo chicks. Photo by Sergey Yeliseev.

Brood parasitism, in which one bird species lays its eggs in another bird's nest, has long been considered a likely cause of coevolution [$a] between brood parasites and their hosts, because the interaction exerts strong natural selection on both species. Hosts suffer major fitness consequences if they take on the raising of another bird's chick—and brood parasite chicks are often bigger, and more aggressive, than their adoptive "siblings," sometimes pushing them right out of the nest. On the other hand, brood parasites run the risk of losing their offspring to hosts who can recognize a strange egg and eject it from the nest.

Programming note

I celebrated the Memorial Day weekend by, among other things, not getting around to writing the final installment of the Big Four series, which was scheduled for sometime this week. I did write up a piece about a neat little study of brood parasitism, which I wanted to discuss while it's fresh anyway.

I'll complete the Big Four series next week, with a discussion of migration.