Yes, yes, evolutionary change occurs in populations, not individuals. But this animation does a rather nice job of illustrating those population-wide changes in the lineages closest to modern humans.
Via The Hairpin.◼
Yes, yes, evolutionary change occurs in populations, not individuals. But this animation does a rather nice job of illustrating those population-wide changes in the lineages closest to modern humans.
Via The Hairpin.◼
This week at The Molecular Ecologist, my friend and collaborator Chris Smith writes, with two coauthors, about a new study simulating adaptive speciation in the face of gene flow, and the effects of linkage among genes involved in the adaptive divergence:
Models of speciation that involve ongoing gene flow remain controversial because gene flow is expected to homogenize differences between populations. However, genome-level effects may facilitate speciation with gene flow. For example, selection against immigrants may have the effect of reducing realized gene flow, even at loci that are not under divergent selection (Rundle & Nosil 2005). This global reduction in gene flow and increased divergence across the genome due to divergent selection is termed ‘Genome Hitchhiking’ (Feder et al. 2012). Genome hitchhiking may be enhanced by fitness epistasis – multiple loci interacting synergistically to cause reductions in fitness that are greater than selection acting on any one locus.
It turns out that speciation is more probable in models that don’t treat genes like independently evolving beans in a beanbag, bearing out a classic criticism of simple speciation models made most prominently by Ernst Mayr. However, true linkage among the selected genes isn’t necessary, either. All in all, this is an exciting new development for those of us who think natural selection might be important in forming new species, so you should definitely go read the whole thing.◼
This week at Nothing in Biology Makes Sense! Devin Drown looks at a new experimental evolution study of adaptation in response to a changing environment—in this case, bacteria evolving in response to increasing concentrations of an antibiotic.
In the case of a rapidly changing environment, there are only a handful of solutions and most of the test populations go extinct before the mutations occur. For populations that experience a slow increase in the deathly poison, there appear to be many more ways to evolve resistance. What is especially fascinating about this research is that it appears that these pathways to resistance are only available when the environment changes slowly.
The results have significant implications for how we expect natural populations to respond to climate change and other human-caused environmental shifts—but it’s also a mighty cool experiment. Go read all about it.◼
In 2006, just about when we were all starting to see the light at the end of the Bush Administration, Sarah Vowell totally rearranged my perspective on U.S. politics:
High school … is the most appropriate metaphor for life in a democratic republic. Because democracy is an idealistic attempt to make life fair. And while high school is the place where you read about the democratic ideal of fairness, it is also the place most of us learn how unfair life really is. Who you are is informed by who you were then. And every nerd has an anecdote or two to tell about how Nerds versus Jocks is not just some epic mythological struggle but a pesky if normal way of life.
Vowell’s essay “The Nerd Voice” (originally published in as part of buy it over on The Partly Cloudy Patriot) starts from the observation that the differences between Presidential candidates Al Gore and George W. Bush are neatly encapsulated in the high school archetypes of Nerd and Jock, and from that spins an entire worldview. Alongside the Nerd are the poor kid, the undocumented kid, the disabled kid, the gay kid—the Democrats’ patchwork coalition of the unpopular lunch table. Arrayed against them: the Jock’s friends the rich kid, the casual racist, the popular kid who never has time for less-popular kids, the socially powerful who need not even acknowledge that they have power. Natural-born Republicans, every one.
More than a decade later, it barely counts as a metaphor to invoke the social strata of the schoolyard in reference to politics. The image of the Bully and the Bullied—the only slightly darker angle on the Nerd and the Jock—is routinely conjured by folks on both sides of the political spectrum to directly describe the actions They want to perpetrate against Us. In this atmosphere, where bullying is simultaneously a political issue and a unifying theory of politics even as the political discourse feeds back to shape the interactions of children in the schoolyard, Emily Bazelon’s book Sticks and Stones offers the hope of understanding not just our own high school traumas, or the experiences of children who are bullied today, but the way social power is wielded in American society.
Sticks and Stones grows out of Bazelon’s extensive writing on bullying for Slate. The book is structured around three specific cases: a girl bullied by upperclassmen for (a least initially) picking the wrong haircut; a gay boy in a rural school district; and a girl accused of contributing to a classmate’s suicide. The details of each case study inform Bazelon’s accounts of the others, and all three serve as starting points for discussion of broader context: the history of public schools’ legal responsbilities to protect students from bullying, historical and ongoing social research, and the evolving role of online media in teenagers’ social lives.
Bazelon’s handling of all this material is clear, precise, and cautious, even as she maintains empathy with (almost) everyone concerned in her three case studies. Early on, she establishes a working definition of bullying (from on the work of pioneering psychologist Dan Olweus), as “verbal or physical aggression that [is] repeated over time and that [involves] a power differential.” This allows differentiation between bullying and “drama,” or jostling for social status among near-equals.
That can still be a difficult line to draw, as the accounts in Sticks and Stones demonstrate—interviewing the bullies in her first case study, Bazelon rapidly establishes that what feels like bullying to the victim is percieved, by the bullies, as normal and necessary social interaction. They’re concerned to learn that the bullied girl, Monique, couldn’t handle their taunting, but not that they’d done something inappropriate.
Monique, in the eyes of these girls … hadn’t learned how to play the game; how to mock other kids and be mocked by them. This was the key to scaling the heights of middle school, if that was your goal. If you wanted to be one of the popular kids in Aminah’s mental chart, you had to learn how to trade barbs, to give as good as you got. … “You have to defend yourself,” Gianna told me.
Sticks and Stones also draws a distinction between kids who bully from positions of social or physical strength (think Mitt Romney, the son of a governor and CEO), and those who bully to shore up a precarious position low in the social pecking order. As Bazelon recounts the case of Jacob, a gay kid dealing with anti-gay bullying in a rural New York high school, it emerges that his chief antagonist may fall into the latter category, the “bully-victim.” Jacob’s bully goes after him in a broader social climate in which queer kids are fair game—where a school administrator can shrug off reported harassment by blaming the victim: “To the extent that the child isn’t ready to project their sexuality in a responsible way, the peers may not respond appropriately, either.”
In that context, a socially marginalized boy looking to prove his toughness has an obvious target.
Bazelon also finds that the roles of bully and bullied can shift rapidly, as demonstrated in the experience of Flannery Mullins, one of several students at South Hadley High in Massechusetts who were accused of bullying a classmate, Phoebe Prince, until she committed suicide. (Bazelon wrote extensively about this case for Slate.) However, it emerges that most of what came to be understood as bullying in the wake of Prince’s suicide originated as interactions that could have looked like nothing more than standard high-school drama over dating relationships—until they interacted, tragically, with Prince’s family life and fragile mental health.
Except, what does that say about what we’re willing to consider “standard high-school drama?”
The picture built in Sticks and Stones suggests that although bullying has become strongly associated with particular parts of society—queer kids, most notably, in the era of “It Gets Better”—there is something about bullying that is quite independent of any particular characteristic that may currently attract bullying. That is, to borrow a thought from Tony Kushner, it is conceivable that some future American society might treat queer young people just the same as it treats straight young people—and still allow all its young people to bully and be bullied, as part of the “normal” cost of growing up.
In other words, the problem of bullying is not about who, specifically, suffers the slings and arrows of life at the bottom of the social ladder. It’s about the existence of the ladder, and what we—parents, school staff, peers—allow teenagers to do and say to establish and enforce their places on it. Sticks and Stones surveys efforts to change exactly these things, and while Bazelon’s description of some specific programs seems hopeful, it’s also clear that they require sustained effort by teachers, administrators, students, and parents—and everyone involved must start from the shared realization that a school’s culture needs to change.
And, on some level, cultural acceptance of bullying is not about particular schools (though, of course, some are worse than others). It’s about our expectations for the very experience of high school. Fixing that will take more than local anti-bullying programs, or legalized marriage equality, or even the best anti-bullying laws. It will require Americans to re-examine how we treat each other, and how we treat those less powerful than us, in the schoolyard and beyond.◼
I was able to read Sticks and Stones for free in advance of publication, via NetGalley.
The 57th edition of the Carnival of Evolution is hosted today at Nothing in Biology Makes Sense! Head over there for a month’s worth of online writing about evolution, scientific history, and the personal experiences of biologists.◼
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I spent last week in Galveston, Texas, for the Gordon Conference on Quantitative Genetics and Genomics. It was a great time. I saw presentations of lots of cool scientific work that was right in line with my current interests—we could’ve started a drinking game with the phrase “missing heritability“—and I presented a little of my own work, and I met some very smart and friendly people. And … that’s pretty much everything I can tell you about it.
That’s because part of the Gordon Conference culture (aesthetic? ideal?) is that participants present and discuss work in progress—results that haven’t been peer-reviewed, and that may never see the light of peer review if they don’t hold up to further analysis. Attendees want to be able to discuss things freely, without seeing their words quoted all over the Internet. So it’s requested, rather firmly, that attendees don’t photograph Powerpoint slides or posters, or discuss specifics from presentations on public forums like this blog, or Twitter. (So I’ve illustrated this post with photos from an afternoon field trip to the Moody Gardens aquarium, instead.)
This is a pretty big departure from my usual approach to scientific conferences. When I was picked to run the website for the 2009 Evolution meetings, I made a point to try and promote online discussion of the conference proceedings. At that early stage—I started my own Twitter account largely to tweet from Evolution—participation was a bit limited. And then I went to ScienceOnline in 2010 and 2011, and saw firsthand how social media can enrich and extend a conference: the tweeted back-channel within a session, the ability to follow goings-on in other sessions, the opening up of discussion to folks beyond the physical conference. And by Evolution 2012, I saw a lot of those dynamics emerging in that meeting.
But back when I was first proposing an online presence at Evolution, I recall some of the same objections raised about blogging and Twitter that are part of the reasons for the ban at Gordon Conferences. People were going to present preliminary results; the prospect of tweeted quotes might stifle discussion; people might get scooped if their work is broadcast over the Internet.
I understand those concerns, but the counterargument to each pops into my head before I finish typing it: it’s no longer uncommon to put preliminary results online for open review (as on ArXive or another preprint server, or in an open lab notebook); are you really going to say something in front of your closest colleagues that you wouldn’t want on Twitter?; aren’t the people most likely to scoop you right there in the conference room, watching your actual presentation? And I think the experience of the Evolution meetings supports the thesis that opening up a conference to the Internet offers far more to improve and stimulate discussion at a meeting than to stifle it.
To be clear, I don’t think it’s bad that the Gordon Conferences ask participants not to tweet. The Quantitative Genetics and Genomics conference is small to the point of being intimate, and strutured to foster all sorts of interactions without the need of hashtags—everyone attends the same slate of invited presentations, everyone ate breakfast, lunch, and dinner together in the hotel dining room, and there are few enough attendees that it really is possible to catch up and chat with anyone you should want to.
And here’s the thing: I didn’t write a blog post or tweet about the presentations I saw, but I took notes, and I talked to people, and I’ve absorbed a whole lot of science that confirmed some things I already thought, challenged some other things, and generally changed the way I’ll think about my current and future scientific work and writing. Even if you don’t have a blow-by-blow account of that process, you’ll see its results on this site and the others where I write about science, and in the work I do from here forward.
Which is just to say that even conferences no one tweets about don’t happen in an Internet-free vacuum. One of the first new friends I made in Galveston was Emily Jane McTavish, who I already knew from Twitter as @snacktavish. It’s pretty much inevitable that our next interaction will be online—because, more and more, scientific discussion happens in cyberspace as much as—probably more than—it happens in hotel conference rooms.◼
So I saw Ed Yong do this, and it looked like a good idea: download the full text of everything I’ve tweeted since I started the @JBYoder feed—you can do this via an option under “settings,” now—and make it into a Wordle. As it happens, my very first tweet was back on the 9th of February, 2009, so this word cloud represents just a bit more than four years of my tweets.◼
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I’m out of town at a conference this week (more on that at a later date), but it’s been a busy one for both blogging and academics. At the Molecular Ecologist, I’ve got a Q&A with Yannick Wurm, the lead author on a cool study that uses high-throughput sequencing data to demonstrate that one species of fire ants has a “social chromosome” which determines how many queens a single colony can support.
In particular this has been extensively studied in the red Solenopsis invicta fire ant: some colonies have up to hundreds of wingless queens, but other colonies contain strictly one single wingless queen. And this is stable: any additional queen you try to add to a single-queen colony is executed by the workers.
Then, at Nothing in Biology Makes Sense! I discuss a new study of local adaptation by a South African daisy, which fools bee flies into mating with its petals, the better to pick up and transport pollen.
What makes G. diffusa more interesting, to an evolutionary biologist, is that not all populations of the daisy practice this deception. The pattern of G. diffusa‘s petals varies across its range—and not all petal patterns prompt the pollinators to hump the flower.
And finally, the first paper from my postdoctoral work in the Tiffin lab is officially online at Systematic Biology. It’s a project in using a very large genetic dataset—tens of thousands of markers—to reconstruct the evolutionary history of the genus Medicago, which includes my current favorite plant. It’s attached to my very first Dryad data package, which provides all the original data underlying the paper. I’ll be writing about this work in more detail in the near future.◼