Why sex? Experiments on fruit flies suggest it evolved to resist infection

August 16, 2015 • 11:45 am

Of course there’s a proximate reason, at least in our species, to the question above: “Why sex?” That answer is fatuous but true: “Because it feels good.” Of course it feels good—because pleasurable orgasms and the desire to copulate are the evolutionary cues prompting us to leave our genes via mating.

But why mate with another individual in the first place? Why not, as do many species, simply reproduce asexually, so that if you’re a female you simply produce offspring from eggs that have not undergone the process of meiosis (i.e., reducing the genome by eliminating one of each pair of chromosomes, a genome restored to fullness when it united with a sperm)? Lots of species can do this, at least occasionally, often by producing unfertilized but viable eggs that have a full chromosome complement.

You can show that there is in fact a significant evolutionary loss caused by having sex, and by undergoing the characteristic processes of sex: recombination (chromosomes swapping bits with the other chromosome of a pair) and segregation (members of different chromosome pairs randomly assorting themselves into eggs or sperm). The loss is in fact two-fold (it’s called “the cost of sex” or “the cost of having males”), so that, all things equal, an individual that can reproduce asexually leaves twice as many copies of its genes as an individual that has sex. In other words, a gene for eliminating sex, and reproducing asexually, should sweep through populations. According to evolutionary theory, every species should reproduce asexually!

But that’s not the case. The vast majority of non-microbial species on Earth reproduce sexually. Given the cost of doing so, there must be some tremendous evolutionary advantage to having sex, one that is strong enough to outweigh the big twofold cost of having sex.

Sadly, evolutionists don’t know what that advantage is, so the evolutionary explanation for the ubiquity of sex is a mystery. It’s one of the great Black Boxes of my field.

One explanation, which has some support, is that having sex enables you to produce more genetically diverse offspring: diversity that is a result of recombination and segregation in the parental genomes. If you have more diverse offspring, perhaps some of them would have the right genetic combinations to withstand infections or other environmental challenges. But if all your offspring are just like you, as in most asexual reproduction, then there’s no chance for diversity. If you can’t resist an infection, neither can your kids. This could select for genes that produce sexual reproduction, allowing some offspring to survive.

This is called the “Red Queen hypothesis” for the evolution of sex, stemming from a scene in Through the Looking Glass in which Alice and the Red Queen are running, but always stay in the same place. The name is appropriate because, if the hypothesis is true, organisms are always running to stay ahead of parasitic infections; but no matter how diverse their offspring are, there will always be new parasites (or newly mutated parasites) that come along, and so the pressure for maintaining sexuality remains.

One can show that, under certain conditions, this increase in the diversity of offspring can select for sexual reproduction—that is, the advantage of having recombination and segregation, and in uniting your egg or sperm with a gamete from another individual, can outweigh the twofold cost of sex. The evidence for this, which is not extensive but still accumulating, is that there is an correlation among populations of some species between infection rate and sexuality. In snails in New Zealand, for example, populations that are infected with a worm that can sterilize them often reproduce sexually, while uninfected populations tend to be asexual. There’s other evidence as well, but it’s of this correlational type.

Now, however, a new paper in Science by Nadia Singh et al. (reference and free download below), suggests that one can see an advantage of one aspect of sex—recombination between members of chromosome pairs—as a response of single individuals within their lifetimes. Using fruit flies, they showed via a series of clever experiments that infected Drosophila produce a higher proportion of recombinant offspring than do uninfected individuals. This suggests not only that parasites might be a factor that selected for sexuality in their hosts, but that hosts can somehow “sense” that they’re infected, and produce more genetically diverse offspring. Having such an evolved “sensing” mechanism would of course be adaptive, allowing you to produce more diverse offspring—for if you’re infected, your offspring are likely to be as well.

Here are two individuals of Drosophila melanogaster, the study organism, having sex. The male, with the black abdomen, is to the right:

What Singh et al. used is an age-old technique in Drosophila: measuring crossing over (recombination) between members of a single chromosome pair (in their case, chromosome 2). This is in fact the way Alfred Sturtevant showed, back at the turn of the 20th century, that genes were lined up on chromosomes in a given order. He was a true genius, and here he is about the time he did that experiment (note the label, which I recall Sturtevant wrote himself):

In the case of Singh et al., the researchers measured crossing over between ebony and rough, two genes on the second chromosome that cross over about 20% of the time. What they did is make females that had the mutant genes (affecting body color and eye texture respectively) on one chromosome, and the two “wild type” non-mutant genes on the other. Since ebony and rough are recessive forms of the genes, these doubly heterozygous females have a normal appearance. However, when you cross them to males homozygous for ebony and rough, you can measure the amount of recombination by the proportion of offspring showing only a single mutant trait (circled in the diagram below, which is from the paper). Normally we see about 20% of these offspring—the further genes are apart on the chromosome, the more crossing over between them will occur, and the more recombinants you see.

It turns out that when the doubly heterozygous females (within dashed box to left above) are infected with the bacteria Serratia marcescens, they produce, when crossed to ebony rough males, significantly more recombinant offspring than do either noninfected or mock-infected females (i.e., those pricked with the injection needle, but with no bacteria injected).

Clearly, infection increased the degree of recombination—one aspect of sexual reproduction—although the p value, showing how likely these results could have been simply a random fluctuation and there was no real effect, was a bit higher than I like. It was 0.03, meaning that even if there was no effect of infection on recombination, the experimenters would observe an effect this large in one of 30 trials. The “cutoff level” is 0.05, so biologists consider p values below that to be “significant”. So these results were marginally significant, explaining why the paper was published in Science, but I’d like to see more experiments, particularly ones showing that the increase in recombination is genome-wide rather than affecting part of one chromosome.

It’s possible that, for reasons we don’t understand, infection simply causes breaks on chromosomes, or on the second chromosome in particular. One could test that as well by seeing if infection by other organisms, like tiny worms, would also have the same effect. Another experiment using injection of heat-killed bacteria showed no effect, so live bacteria are required to initiate the production of more-diverse progeny. More important, an experiment with wasps (see below) gave a similar result.

There are two other explanations for the increase in the proportion of single-mutant offspring. One is mitotic recombination: that crossing over might occur not during sperm and egg formation (at the time when “sister chromosomes” pair up), but beforehand. Alternatively, there might be transmission distortion, so that there is no increase in the amount of crossing-over, but that the recombinant chromosomes somehow get preferentially sorted into the eggs, making it look as if there was an increase in crossing over. In all cases this could still represent an adaptive evolutionary response, for all three mechanisms yield a higher proportion of more diverse offspring. What we’re talking about here is simply the mechanism of getting more diverse offspring.

I won’t go into details, but you can test these alternative mechanisms by taking advantage of two features of Drosophila: males show no crossing over during sperm formation (we have no idea why this is!), and because all “normal” recombination occurs 4-5 days before fertilized eggs are laid. Ergo, if the appearance of recombinant offspring increases after this, it must be transmission distortion. It turns out that the increase in the number of recombinant offspring does indeed appear due to transmission distortion: recombinant chromosomes are preferentially put into the eggs. We have no idea how this is done.

Finally, the authors did one more experiment, injecting Drosophila larvae with parasitic wasps rather than bacteria (these wasps are a normal predator on fly larvae in nature). And, as with the bacteria, the female larvae that successfully fought off the wasp infections grew up (after pupating) to produce a higher proportion of recombinant offspring than control, uninfected larvae. Below is the figure showing the difference, which was even more significant (p = 0.0002) than with the bacteria. The proportion of recombinant progeny is on the left scale, and it’s lower in control than infected wasps:

Screen Shot 2015-08-16 at 9.11.48 AM — (From paper): Box plots illustrating the distribution of recombination fractions in D. melanogaster strain RAL73 in control and wasp-infected females. The median is marked with a black line; the first and third quartiles are rep- resented as lower and upper edges of the box, respectively. The whiskers extend to the most extreme data point no farther from the box than 1 times the interquartile range. Recombination fraction is shown estimated over the entire 12-day egg-laying period

The curious thing here is that these are larvae that are infected, and larvae haven’t yet developed the cells that produce eggs. Somehow the effect of being infected carries over from the larval to the adult stage.

This result, then, adds to the growing pile of data suggesting that, at least in some cases, the evolution of sex is connected with resistance to infectious agents—i.e., that sex is an adaptive response that wards off infections by producing so many diverse progeny that some of them will have combinations of genes that resist infection. Or, to say it yet another way, genes for sexual reproduction are advantageous because they happen to be present in those individuals that have other genes allowing them to better survive infections. Sex genes “hitchhike” on infection-resisting genes.

The paper of Singh et al., however, extends previous work because it shows that an adaptive response can evolve not just over generations, but can be a plastic one: that recombination can be increased during one’s lifetime when an infection is detected. (That response, of course, if it’s truly adaptive and not just an epiphenomenon, must also have evolved over generations.)

Is infection, then, a general selective force that produced sexuality in most species?

Who knows? Sexuality is nearly universal in multicellular organisms, but were all of them subject to strong selection by infectious agents that overcame the high cost of sexual reproduction? Of course once you develop the complicated apparatus of sexual reproduction, it’s hard to go back, so there’s a kind of inertia that can retain sexual reproduction even if it’s no longer advantageous. But, contra that, there are many cases of sexually-reproducing species having some asexual reproduction, so this reverse evolution can and does happen. Why don’t sexual organisms revert more often to asexual ones, given the advantage of asexuality? Is infection that pervasive, and such a strong selective force? Or are there other factors that select for sexual reproduction?

Here are some questions I have that would extend this paper, which—make no mistake about it—is very good.

Is infection-induced “recombination” (i.e., transmission distortion) in flies specific to the second chromosome? It would be nice to know whether recombination is increased throughout the genome, as one would expect were the Red Queen Hypothesis true. This would be an easy experiment to do.

Could you show the evolution of higher recombination in the laboratory? You could set up “population cages,” each containing a large number of genetically diverse flies, and then infect half the cages, leaving the other half as controls. After a year or so (about 25 generations), you might expect to see the evolution of higher recombination in the infected cages. It would be best to do sequential infection using several agents, as one would like to impose constant selection on the flies, and if you’re fully adapted to an infectious agent—so that it no longer harms you—then there’s no further selection for sexual reproduction.

One thing I should add at the end is that we’ve long known that artificial selection for increased recombination is highly successful in Drosophila. You can, for instance, take the kind of females shown above, and choose for further breeding the ones that produce a higher proportion of recombinant offspring. Over generations, this can lead to a pretty strong increase in recombination (you can also select for decreases). Further, you can also select for increased recombination between a specific pair of genes on a single chromosome, leaving the rest of the genome with no change. Clearly there are genes around with variants that can change the rate of recombination, which of course is a prerequisite if that aspect of sexuality evolved as an adaptation.

Tenniel_red_queen_with_alice — Alice and the Red Queen

_____

Singh, N. D. et al. 2015. Fruit flies diversity their offspring in response to parasite infection. Science 349:747-750.

Oliver Sacks on the Sabbath—and his death

August 16, 2015 • 10:15 am

As most of you know, Oliver Sacks is in the process of dying. His metastatic cancer began in his eye, and then spread to his liver and now to other places. He doesn’t have long to live, and has documented his decline, and his thoughts on impending mortality, in three pieces in the New York Times. I posted on the first one in February, and another,called “”My periodic table,” appeared in February. In that one he matched the latter years of his life with the corresponding number of a chemical element in the periodic table. An excerpt:

I started a new sort of treatment — immunotherapy — last week. It is not without its hazards, but I hope it will give me a few more good months. But before beginning this, I wanted to have a little fun: a trip to North Carolina to see the wonderful lemur research center at Duke University. Lemurs are close to the ancestral stock from which all primates arose, and I am happy to think that one of my own ancestors, 50 million years ago, was a little tree-dwelling creature not so dissimilar to the lemurs of today. I love their leaping vitality, their inquisitive nature. [JAC: My colleague Anne Yoder is director of that Center and showed him around. Her post on the Duke Lemur Center Facebook page says this: “It was such an amazing 24 hours. He is every bit as kind, generous, and full of wonder as you could imagine.”]

. . . Bismuth is element 83. I do not think I will see my 83rd birthday, but I feel there is something hopeful, something encouraging, about having “83” around. Moreover, I have a soft spot for bismuth, a modest gray metal, often unregarded, ignored, even by metal lovers. My feeling as a doctor for the mistreated or marginalized extends into the inorganic world and finds a parallel in my feeling for bismuth.

I almost certainly will not see my polonium (84th) birthday, nor would I want any polonium around, with its intense, murderous radioactivity. But then, at the other end of my table — my periodic table — I have a beautifully machined piece of beryllium (element 4) to remind me of my childhood, and of how long ago my soon-to-end life began.

Today’s Times has a further installment, “Sabbath,” which shows how Sacks, and some other secular Jews, still hang onto old religious rituals. (He’s an atheist.) I don’t adhere at all to religious ritual—although I used to have a mezuzah on my lintel—but it’s fascinating to see what one one clings to at the end of life. I briefly thought that Sacks was being solipsistic, parading his illness before the public, but I instantly realized that he’s doing exactly what Hitchens was doing at the end of his life: these men are writers, and their first response to nearly everything is to put it into words for others. Perhaps that helps bring coherence to their thoughts, or even provides some solace, but what it certainly does do is give us unique insights about what it’s like to die. It’s sad, and it’s wrenching, but, as Bonnie Raitt said, it’s what we all go through.

An excerpt from “Sabbath”:

In December 2014, I completed my memoir, “On the Move,” and gave the manuscript to my publisher, not dreaming that days later I would learn I had metastatic cancer, coming from the melanoma I had in my eye nine years earlier. I am glad I was able to complete my memoir without knowing this, and that I had been able, for the first time in my life, to make a full and frank declaration of my sexuality, facing the world openly, with no more guilty secrets locked up inside me.

In February, I felt I had to be equally open about my cancer — and facing death. I was, in fact, in the hospital when my essay on this, “My Own Life,” was published in this newspaper. In July I wrote another piece for the paper, “My Periodic Table,” in which the physical cosmos, and the elements I loved, took on lives of their own.

And now, weak, short of breath, my once-firm muscles melted away by cancer, I find my thoughts, increasingly, not on the supernatural or spiritual, but on what is meant by living a good and worthwhile life — achieving a sense of peace within oneself. I find my thoughts drifting to the Sabbath, the day of rest, the seventh day of the week, and perhaps the seventh day of one’s life as well, when one can feel that one’s work is done, and one may, in good conscience, rest.

That’s so sad, and so eloquent. Goodbye, Oliver. You made the world a better place—by helping others who were troubled and by giving us glimpses into not only their minds, but yours.

Readers’ wildlife photographs

August 16, 2015 • 7:30 am

I’m getting a bit antsy that the photo tank is running low, so, readers, BRING OUT YOUR PICTURES and send me the good ones. We still have a backlog, though. Reader Bob Lundgren sent some lovely photographs of elephants. The notes are his:

Thought I would send along some photos of African elephants (Loxodanta africana) we encountered on our trip to Tanzania in January. These are a combination of my photos and my wife’s. They’ve gotten mixed together in our photo library so it’s difficult to tell which are whose anymore. Generally, though, assume the best photos are hers.

The first six photos were taken in Tarangire National Park, Tanzania. This is a 2850 sq. km. (1096 sq. mi.) park located in east central Tanzania, south of the Serengeti. Because of its location in relation to the “wildebeest/zebra great migration” Tarangire has fewer safari visitors than the Serengeti. But if you want to see elephants – lots of elephants – Tarangire is the place to go. It’s estimated that there are about 2500 elephants within the park boundaries.

The first photo shows a small herd in their preferred wooded savanna/forest habitat. If the camera were to pan left and right in a 180 degree arc there would be seen several other similar sized groups scattered throughout the woodland. The trees are Yellow-Barked Acacia (I think). The red coloration of the elephants comes from the dust and mud that they use to protect their skin from the sun.

The second photo is a close-up of a single individual. Note the large ears – very different from those of the Asian elephant. The African elephant’s ears have many blood vessels near the surface on the back side. This helps with cooling, particularly when the elephants flap their ears.

The third photo is a detail of the trunk showing the two “fingers” at the tip. This is also very different from Asian elephants. Asian elephants have only one “finger”. The two opposable “fingers” of the African Elephant give it the ability to grasp small tufts of grass and other small items. It’s marvelous to watch the delicacy of this at the end of the massive trunk. Indeed, the flexibility and utility of the entire trunk is fascinating to observe.

The fourth photo is a detail of a baobab tree (Adansonia digitata) showing the damage elephants can do by rubbing against the bark. This particular tree was a favorite. Elephants will also damage baobabs during the dry season since the baobab bark can hold lots of water. While elephants certainly damage trees, the damage is sporadic. We saw very few baobabs with this type of damage and very little elephant-caused habitat damage overall. Baobab trees are the other thing, besides elephants, that Tarangire is noted for. There are many magnificent old-agers throughout the park.

The fifth photo is of an individual elephant on the grounds of the permanent tented lodge where we stayed. The lodge is long established and located on a ridge overlooking the Tarangire River. A large herd of elephants makes the area home and small groups regularly amble through the grounds from the river valley below to the savanna pasture beyond the lodge. When this happens the personnel at the lodge are diligent in keeping people and elephants at a safe distance from each other. The elephants have posed little danger and have caused little damage over the years. Any damage is usually the result of curious or rambunctious youngsters. The lodge has a photo of a youngster playing “Whack-a Mole” with the low bollard path lighting. Recently the lodge also posted some photos on their Facebook page of elephants becoming interested in the goings on at the swimming pool – curious heads and trunks poking over the surrounding wall.

The sixth photo is of a relatively fresh elephant carcass with White Backed Vultures (Gyps africanus) fulfilling their role. Our guide, Mussa, was quite suspicious of this. Because the carcass was close to a road, he was concerned that it might have been poached for the tusks. Indeed the tusks were gone, but he talked to some park rangers we encountered later and was assured that this was a natural death. The rangers harvest and destroy the tusks of dead elephants when they find them to discourage poachers. Poaching is a bit of a problem for the park, however, because of the density of elephants. We came across two other elephant carcasses later (apparently natural deaths). These had been completely scavenged. Only the skin remained, looking like a deflated tire.

The seventh and eighth photos are of a small herd at a mostly dry river bed in Lake Manyara National Park. Again, if the camera in the first photo were to pan to the right 180 degrees another twenty or thirty elephants would be seen. These were the only elephants we saw in this park. The eighth photo shows a youngster in mid dust bath behavior.

The ninth photo is a close up of one of two bulls that approached us near the Ikoma Gate in the central Serengeti. This particular individual ambled quite close to the vehicle and gave us a look for awhile. There was nothing threatening about it. No doubt he was wondering what we were, as elephants have poor eyesight. After we communed for a few minutes he moved off to join his buddy.

The tenth photo is probably the oldest bull we saw. This fellow was in Ngorogoro Crater and had magnificent tusks. The elephants in Ngorogoro Crater are relatively safe from poachers since there are only two well secured roads into the crater. The few elephants here can live to a ripe old age.

Sunday: Hili dialogue and Leon lagniappe

August 16, 2015 • 6:00 am

It’s Ceiling Cat’s Day, and all moggies should rest (as they do the other six days of the week). It’s been very hot in Dobrzyn, in the thirties (Centigrade), but seems to affect the staff more than Hili. In fact, she’s even flaunting her fur. Look at this insouciant cat!

A: That fur is very becoming on you.
Hili: I know.

In Polish:

Ja: Do twarzy ci w tym futerku.
Hili: Wiem.

And Leon continues his hiking adventures in the mountains. Here he is in his backpack, urging on his staff:

Leon: Let’s go a bit faster. I’ve heard that we are going to have a trout for dinner

11061278_1006499416037326_9123735300270773523_n

A funny email

August 15, 2015 • 1:00 pm

A reader who will remain unnamed sent me an email that made me chuckle:

I’m currently about half way through your Faith vs. Fact and finding it a most pleasurable experience to read something which is at once so authoritative and so totally in accord with everything I already believe about the relationship between science and religion.

All the more disquieting then, to report that my reaction to the very first line of text in Chapter One was a guffaw of disbelief:

‘There are no heated discussions about reconciling sport and religion…’

I’m glad I overcome my initial scorn and persisted with your excellent book, but I do have to ask you a simple question:

‘Have you ever been to Glasgow?’

On the hair-trigger sensitivity of today’s college students, and how to fix it

August 15, 2015 • 11:00 am

The cover story for the September issue of The Atlantic is a curious one, a long one, and well worth a read. “The coddling of the American mind” has two authors, Greg Lukianoff and Jonathan Haidt. Lukianoff is president of FIRE (the Foundation for Individual Rights in Education), and has done great work trying to keep campuses from quashing free speech. In contrast, Haidt is an academic social psychologist at New York University, and has written extensively—and often perceptively—on human morality.

This is an odd collaboration, but it works well for the article, which attempts first to recount and diagnose the attacks on free speech at American colleges (you’ll be familiar with some of the examples, but others are new and disturbing), and then to figure out how to treat students in a way that will mitigate these attacks. The first part is Lukianoff’s purview, the second Haidt’s. Haidt draws connections between student behavior and the type of distorted thinking that’s treated with cognitive behavioral therapy (CBT).

Further, in a supplementary backstory piece online, both men have experience with the other’s area: Lukianoff suffered from deep depression that made him ponder warped thinking, while Haidt encountered the hypersensitivity of today’s students while teaching at NYU.

I’m not going to summarize the piece in detail, as you really should read it as a Professor Ceiling Cat Recommendation™. I will, however, give some quotes—more than usual with an eye toward those with limited time—dividing the article into subtopics.

The problem (this will be familiar to regular readers):

A movement is arising, undirected and driven largely by students, to scrub campuses clean of words, ideas, and subjects that might cause discomfort or give offense. Last December, Jeannie Suk wrote in an online article for The New Yorker about law students asking her fellow professors at Harvard not to teach rape law—or, in one case, even use the word violate (as in “that violates the law”) lest it cause students distress. In February, Laura Kipnis, a professor at Northwestern University, wrote an essay in The Chronicle of Higher Educationdescribing a new campus politics of sexual paranoia—and was then subjected to a long investigation after students who were offended by the article and by a tweet she’d sent filed Title IX complaints against her. In June, a professor protecting himself with a pseudonym wrote an essay for Vox describing how gingerly he now has to teach. “I’m a Liberal Professor, and My Liberal Students Terrify Me,” the headline said. A number of popular comedians, including Chris Rock, have stopped performing on college campuses (see Caitlin Flanagan’s article in this month’s issue). Jerry Seinfeld and Bill Maher have publicly condemned the oversensitivity of college students, saying too many of them can’t take a joke.

. . . Two terms have risen quickly from obscurity into common campus parlance. Microaggressions are small actions or word choices that seem on their face to have no malicious intent but that are thought of as a kind of violence nonetheless. For example, by some campus guidelines, it is a microaggression to ask an Asian American or Latino American “Where were you born?,” because this implies that he or she is not a real American. Trigger warnings are alerts that professors are expected to issue if something in a course might cause a strong emotional response. For example, some students have called for warnings that Chinua Achebe’s Things Fall Apart describes racial violence and that F. Scott Fitzgerald’s The Great Gatsby portrays misogyny and physical abuse, so that students who have been previously victimized by racism or domestic violence can choose to avoid these works, which they believe might “trigger” a recurrence of past trauma.

A bactrian example. This is bizarre but by no means unusual. I give one example, but there are many similar ones in the article.

These examples may seem extreme, but the reasoning behind them has become more commonplace on campus in recent years. Last year, at the University of St. Thomas, in Minnesota, an event called Hump Day, which would have allowed people to pet a camel, was abruptly canceled. Students had created a Facebook group where they protested the event for animal cruelty, for being a waste of money, and for being insensitive to people from the Middle East. The inspiration for the camel had almost certainly come from a popular TV commercial in which a camel saunters around an office on a Wednesday, celebrating “hump day”; it was devoid of any reference to Middle Eastern peoples. Nevertheless, the group organizing the event announced on its Facebook page that the event would be canceled because the “program [was] dividing people and would make for an uncomfortable and possibly unsafe environment.”

The psychological background and cause of the problem:

The press has typically described these developments as a resurgence of political correctness. That’s partly right, although there are important differences between what’s happening now and what happened in the 1980s and ’90s. That movement sought to restrict speech (specifically hate speech aimed at marginalized groups), but it also challenged the literary, philosophical, and historical canon, seeking to widen it by including more-diverse perspectives. The current movement is largely about emotional well-being. More than the last, it presumes an extraordinary fragility of the collegiate psyche, and therefore elevates the goal of protecting students from psychological harm. The ultimate aim, it seems, is to turn campuses into “safe spaces” where young adults are shielded from words and ideas that make some uncomfortable. And more than the last, this movement seeks to punish anyone who interferes with that aim, even accidentally. You might call this impulse vindictive protectiveness. It is creating a culture in which everyone must think twice before speaking up, lest they face charges of insensitivity, aggression, or worse.

. . . In this essay we focus on a different question: What are the effects of this new protectiveness on the students themselves? Does it benefit the people it is supposed to help? What exactly are students learning when they spend four years or more in a community that polices unintentional slights, places warning labels on works of classic literature, and in many other ways conveys the sense that words can be forms of violence that require strict control by campus authorities, who are expected to act as both protectors and prosecutors?

But vindictive protectiveness teaches students to think in a very different way. It prepares them poorly for professional life, which often demands intellectual engagement with people and ideas one might find uncongenial or wrong. The harm may be more immediate, too. A campus culture devoted to policing speech and punishing speakers is likely to engender patterns of thought that are surprisingly similar to those long identified by cognitive behavioral therapists as causes of depression and anxiety. The new protectiveness may be teaching students to think pathologically.

. . . Because there is a broad ban in academic circles on “blaming the victim,” it is generally considered unacceptable to question the reasonableness (let alone the sincerity) of someone’s emotional state, particularly if those emotions are linked to one’s group identity. The thin argument “I’m offended” becomes an unbeatable trump card. This leads to what Jonathan Rauch, a contributing editor at this magazine, calls the “offendedness sweepstakes,” in which opposing parties use claims of offense as cudgels. In the process, the bar for what we consider unacceptable speech is lowered further and further.

Lukianoff and Haidt impute the problem to the atmosphere of greater protectiveness that coincided with parents becoming more worried about and attentive to their kids’s welfare (children can no longer ride their bikes around the neighborhood or go out on their own without parental supervision, something that was unthinkable when I was a child), and to the increasing polarization of American life and politics: an “us versus them” mentality. (They don’t dig deeper than this.) Another cause—to me an important one—is the rise of social media. The authors laud that media as a tool for increasing the connectivity among people, but also warn of its side effects:

But social media has also fundamentally shifted the balance of power in relationships between students and faculty; the latter increasingly fear what students might do to their reputations and careers by stirring up online mobs against them.

And this doesn’t just affect colleges, but even adults, and adults in the atheist “movement”. The infusion of that movement, which once looked so promising, with diverse notions of “social justice”—notions that often conflicted with each other (and I do see a natural but not inevitable nexus between atheism and creating a better world)—when combined with the naming and shaming implicit in social media, has produced a sad debasement of online atheism. It’s not just college students who are afflicted with distorted thinking and identity-politics sensitivity, for at this very moment a prominent atheist blog network is falling apart, ripped asunder by internecine fights about Proper Thinking. But I digress.

The solution. It involves using methods from CBT to help students. Here are Lukianoff’s and Haidt’s proposals:

a. Change government policy.

The biggest single step in the right direction does not involve faculty or university administrators, but rather the federal government, which should release universities from their fear of unreasonable investigation and sanctions by the Department of Education. Congress should define peer-on-peer harassment according to the Supreme Court’s definition in the 1999 case Davis v. Monroe County Board of Education. The Davis standard holds that a single comment or thoughtless remark by a student does not equal harassment; harassment requires a pattern of objectively offensive behavior by one student that interferes with another student’s access to education. Establishing the Davis standard would help eliminate universities’ impulse to police their students’ speech so carefully.

b. Abandon university restrictions on speech:

Universities themselves should try to raise consciousness about the need to balance freedom of speech with the need to make all students feel welcome. Talking openly about such conflicting but important values is just the sort of challenging exercise that any diverse but tolerant community must learn to do. Restrictive speech codes should be abandoned.

c. Abandon trigger warnings, which don’t work. Lukianoff and Haidt cite research showing that the way to desensitive students to potentially “traumatic’ material is not to censor it, but to expose them to it:

Universities should also officially and strongly discourage trigger warnings. They should endorse the American Association of University Professors’ report on these warnings, which notes, “The presumption that students need to be protected rather than challenged in a classroom is at once infantilizing and anti-intellectual.” Professors should be free to use trigger warnings if they choose to do so, but by explicitly discouraging the practice, universities would help fortify the faculty against student requests for such warnings.

They make one more suggestion that seems reasonable, and is probably the most effective thing universities could do to ameliorate the problem, but it seems to me unworkable, as it implies to an already overly-sensitive group of students that they need therapy. Imagine!

d. Teach CBT to incoming college students.

Finally, universities should rethink the skills and values they most want to impart to their incoming students. At present, many freshman-orientation programs try to raise student sensitivity to a nearly impossible level. Teaching students to avoid giving unintentional offense is a worthy goal, especially when the students come from many different cultural backgrounds. But students should also be taught how to live in a world full of potential offenses. Why not teach incoming students how to practice cognitive behavioral therapy? Given high and rising rates of mental illness, this simple step would be among the most humane and supportive things a university could do. The cost and time commitment could be kept low: a few group training sessions could be supplemented by Web sites or apps. But the outcome could pay dividends in many ways. For example, a shared vocabulary about reasoning, common distortions, and the appropriate use of evidence to draw conclusions would facilitate critical thinking and real debate. It would also tone down the perpetual state of outrage that seems to engulf some colleges these days, allowing students’ minds to open more widely to new ideas and new people. A greater commitment to formal, public debate on campus—and to the assembly of a more politically diverse faculty—would further serve that goal.

I’m familiar with freshman “orientation sessions”, a lot of which are frankly ludicrous, trying to shame and bully new students into a “politically correct” frame of mind, one that comports with the college’s need to eliminate anything that might considered offensive. Those should be ratcheted down, but I don’t think CBT is practical here. As I said, students will already be offended at the notion that they need tools to correct any warped thinking. That implies that they’re capable of or prone to warped thinking, a suggestion that’s already “offensive,” though Haidt and Lukianoff mean it in the best way possible.

Readers’ wildlife photos

August 15, 2015 • 9:00 am

It’s Robin Saturday! Reader Jay Haas of Point Reyes, California makes his first appearance by contributing some albino robins:

Here are some photos from a few years ago of a white (partial albino) robin, American robin (Turdus migratorius), which lived in my yard for several days. As I understand it about one robin in 30,000 is an albino or partial albino, and totally albino birds have no pigment in their irises and retinas to protect their eyes from sunlight, and many eventually go blind.

Reader Randy Shenck also sent some robin pics:

Sometimes in the summer we sit outside in the evening to better hear what might be going on and that is what rural life is all about. The American Robin (Turdus migratorius) is the most abundant of all the birds around here. The first one seems to have an attitude and the second has a grub. It is common this time of day to count twenty to thirty robins on the ground at one time.

Stephen Barnard bought another toy: a drone. I doubt that we’ll get many wildlife photos from it, as it’s noisy and intrusive, but one can hope. In the meanwhile, he’s testing it outL

Here’s some drone video in 1080p I uploaded to Flickr. I flew from my house across the creek and field to harass the horses. (I’m not quite intuitive with the camera tilt yet.) Then I went on autopilot to returnhome.

There’s nothing special about this video, but it gives you an idea of what I’m up to. Wait until I shoot the elk. [He means scaring off the elk with the drone, not firing guns at them!]

Click on the screenshot to go to the video:

A microburst in Arizona

August 15, 2015 • 8:45 am

A burst is a column of cool air that, being heavier than warm air, sinks to the ground rapidly and dissipates, causing high winds. When a small portion of such air is laden with water from a storm, and drops to the ground, you get the famous microbursts. (We had one in Chicago about a decade ago, which knocked down nearly every lamppost and tree on my block.) Here’s a particularly vivid one from near Tucson.

A time lapse of a strong thunderstorm that dropped a couple of wet microburst. One in particular was captured really well in the time lapse thanks to the sun peaking out to the west. Notice how the ball of rain falls from the sky and starts separating before hitting the ground. Once it hits the ground you can see the power of microburst as it expands similar to the ripple you would see when you drop a stone in water.

Here’s a figure from Wikipedia that explains what’s happening in the video: that shows what’s happening.

h/t: John W.

	Debi on Jesse Singal on the ridiculous…
	Mark Sturtevant on Bill Maher on gender apartheid
	Mike on Bill Maher on gender apartheid
	Laingholm on Jesse Singal on the ridiculous…
	Emily on Bill Maher on gender apartheid