ريتشارد دوكنز's Blog, page 531
March 22, 2016
“Genetic Scissors” Can Completely Eliminate HIV From Cells
Photo credit: NIH via Flickr, CC by 2.0
By Alexandra Ossola
Thanks to the cocktail of drugs that make up antiretroviral therapy, HIV is no longer a death sentence. But there are downsides to antiretroviral therapy—taking the treatment for many years is expensive, increases drug resistance, and could cause adverse reactions in a patient. And, because the virus stays in reservoirs in the body, the disease can continue to progress in patients if they stop taking their medication.
Now a team of German researchers has found an enzyme that can “cut” the viral DNA out of a cell’s genetic code, which could eradicate the virus from a patient’s body altogether. The proof-of-concept study, published this week in Nature Biotechnology and reported by Ars Technica, was done in mice, but the researchers believe that their conclusions show that this DNA-snipping enzyme could be used in clinical practice. And if it can cut HIV’s genetic code out of a patient’s body, the technique could be a cure for the disease.
The researchers created the DNA-snipping enzyme called Brec1 using directed evolution, an engineering technique that mimics proteins’ natural evolution process. They programmed the enzyme to cut DNA on either side of a sequence characteristic of HIV—a difficult task since the DNA of organisms and of the virus itself mutates often. Still, the researchers identified a well-conserved sequence, then they tested how reliably the enzyme could snip out that sequence in cells taken from HIV-positive patients, in bacteria, and in mice infected with the human form of HIV. After a number of tweaks, Brec1 would cut only that sequence of DNA, patching up the cell’s genetic code once the HIV sequence was cleaved out. After 21 weeks, the cells treated with Brec1 showed no signs of HIV.
The Regressive Left Is Losing The Campus War
Photo credit: Edwin Gano
By Allum Bokhari
A turning point is underway in the culture wars over American universities. Dismayed by their wild-eyed radicalism and anti-intellectual demands, college faculties, administrators, and much of the media are turning their backs on the regressive left.
Left-wing activists have been running rampant on college campuses for years. In 2014, the Foundation for Individual Rights in Education (FIRE) found that the number of speaker disinvitations on campus, typically prompted by the allegedly “offensive” views of a visiting speaker, had more than tripled over ten years. Activist crusades against cultural appropriation, sexism and racism have led to the banning of an eclectic range of items on campus, from Charlie Hebdo to mini-sombreros.
In one low point, student leaders at the University of Minnesota blocked a proposed annual moment of remembrance for 9/11 on the grounds that it could promote “Islamophobia.”
Previously quick to take the side of students demanding “safety” from offensive speech (Minnesota’s faculty quickly complied with activist’s demands to censor Charlie Hebdo, for example), it now seems that colleges administrators have had enough with the regressive left.
The President of Oberlin, an infamously liberal college, recently rebuffed a list of demands from left-wing activists on campus, the University of Missouri has been uncompromising in its decision to fire radical assistant professor Melissa Click over her attempted physical intimidation of a student reporter, and a growing number of professors are now speaking out against the culture of safe spaces and censorship on campus.
Of course, these efforts feel a little like Pandora trying to close her box — campus faculties trying to contain campus crazies they themselves helped create.
The campus crazies are still winning some victories, like Princeton and Harvard’s removal of the academic title “Master” over complaints that it conjured memories of slavery. But the flames of resistance are quickly flickering to life. Allies of the regressive left grow harder to find, while new opponents appear every day. After all, the regressive types manufacture a new enemy everytime they decide that an ally or a sympathiser isn’t ideologically pure enough for them.
The regressive left played into the hands of its opponents with hysterical responses to recent visits to U.S campuses from Breitbart Tech editor Milo Yiannopoulos and Professor Christina Hoff Sommers of the American Enterprise Institute.
The Daoud Affair
Photo credit: Henning Kaiser/picture-alliance/dpa/AP Images
By Paul Berman and Michael Walzer
Last month the Algerian novelist and journalist Kamel Daoud astonished the readers of Le Monde in Paris by threatening to renounce journalism, not because he is afraid of Islamists at home in Algeria, though a fatwa has been issued against him, but for another reason, which is still more dismaying. He has been severely condemned by people from the Western intellectual class, and silence seems to him an appropriate response.
The denunciations of Daoud are a distressing development. And they are doubly distressing because they conform to a pattern that has become familiar. It goes like this: A writer with liberal ideas emerges from a background in the Muslim countries, or perhaps lives there now. The writer proposes criticisms of Islam as it is practiced, or of sexual repression under Islamic domination (a major theme), or of the Islamist movement. The criticisms seem blasphemous to the Islamists and the reactionary imams, who respond in their characteristic fashion. In the Western countries, intellectuals who mostly think of themselves as progressive make their own inquiry into the writer and his or her ideas. They hope to find oblique and reticent criticisms of a sort that they themselves produce. But they find something else—criticisms that are angrier and more vehement, or more sweeping, or more direct.
The Western intellectuals, some of them, recoil in consternation. And, as if liberated from their reticence, they issue their own condemnation of the offending writer, not on grounds of blasphemy but on grounds that purport to be left-wing. The Western intellectuals accuse the liberal from the Muslim world of being a racist against Muslims, or an Islamophobe, or a “native informant” and a tool of imperialism. Sometimes they accuse the liberal from the Muslim world of stupidity, too, or lack of talent. This was Salman Rushdie’s experience in the years after he came out with The Satanic Verses, back in 1988, which he has described in his memoir Joseph Anton. The experience of Ayaan Hirsi Ali, originally from Somalia, offers probably the most widely discussed example after Rushdie’s. But the pattern of Western condemnation can be observed in many other cases as well, directed at liberal writers of different kinds and views—the authors of political essays, memoirs, literary criticism, journalism, and novels, from backgrounds in countries as diverse as Egypt, Iran, Afghanistan, and Pakistan. Kamel Daoud’s Algerian colleague, the novelist Boualem Sansal, last year’s winner of a prize from the French Academy, has come under this kind of condemnation. And now the pattern has reemerged in regard to Daoud himself.
Daoud stands high on the world scene because of his novel, The Meursault Investigation, which adds a philosophical dimension to the affair. The book is an homage to Albert Camus, and a rebuke. In 1942 Camus published a novel titled The Stranger, which tells the story of a French Algerian named Meursault, who gratuitously murders a nameless and silent Arab on the beach. Daoud in The Meursault Investigation tells the story of the murdered man’s younger brother, who contemplates what it means to be rendered nameless and silent by one’s oppressor. In France, Daoud’s reply to Camus won the Goncourt Prize for a First Novel in 2015, among other prizes. In the United States, it received two of the greatest blessings that American journalism can bestow on a writer not from the United States. The New Yorker published an excerpt. And the New York Times Magazine published a full-length admiring profile.
These triumphs created a demand for Daoud’s journalism, as well. For 20 years he has written for the Algerian newspaper Le Quotidien d’Oran, but, in the wake of his novel’s success, his journalism began to appear prominently in Le Monde and other European newspapers. He was invited to write for the New York Times. And he responded to these opportunities in the way that any alert and appreciative reader of his novel might have expected.
He offered insights into the Islamic State. He attacked Saudi Arabia, with a side jab aimed at the extreme right in France. But he also looked at the mass assault on women that took place in Cologne on New Year’s Eve by a mob that is thought to have included men from the Arab world. He dismissed a right-wing impulse in Europe to regard immigrants as barbarians. And he dismissed a left-wing, high-minded naïveté about the event. He pointed to a cultural problem. In the New York Times he wrote: “One of the great miseries plaguing much of the so-called Arab world, and the Muslim world more generally, is its sick relationship with women.” More: “The pathological relationship that some Arab countries have with women is bursting onto the scene in Europe.” In Le Monde he wrote that Europe, in accepting new immigrants and refugees, was going to have to help them accept new values, too—“to share, to impose, to defend, to make understood.” And now his troubles began.
A group of 19 professors in France drew up a statement accusing Daoud of a series of ideological crimes, consisting of “orientialist cliches,” “essentialism,” “psychologization,” “colonialist paternalism,” an “anti-humanist” viewpoint, and other such errors, amounting to racism and Islamophobia. Le Monde published their accusations. A second denunciation came his way, this time in private. It was a letter from the author of the New York Times Magazine profile, the American literary journalist Adam Shatz. In his letter Shatz professed affection for Daoud. He claimed not to be making any accusations at all. He wrote, “I’m not saying you’re doing it on purpose, or even that you’re playing the game of the ‘imperialists.’ I’m not accusing you of anything. Except perhaps of not thinking, and of falling into strange and potentially dangerous traps”—which amounted to saying what the 19 professors had said, with the additional accusation of stupidity.
Daoud published the American journalist’s letter in Le Monde, just to make clear what he was up against—though he did it with an elegant show of friendliness. He explained that he, and not his detractors, lives in Algeria and understands its reality. He noted the Stalinist tone of the attacks on him. He insisted on the validity of his own emotions. He refused to accept the political logic that would require him to lapse into silence about what he believes. And then, in what appeared to be a plain and spiteful fury at his detractors, he declared that he is anyway going to do what the detractors have, in effect, demanded. He is going to silence his journalism: a gesture whose emotional punch comes from The Meursault Investigation, with its theme of silence. Or, at minimum, Daoud threatened to be silent—though naturally the calls for him to continue speaking up have already begun, and doubtless he will have to respond.
Supernova shockwave seen with visible light for first time
Photo credit: YouTube/NASA Ames/ STScI/G.Bacon
By Michael Slezak
The final violent death throes of a star has been seen with visible light for the first time and provided a fresh mystery for astronomers.
Scientists think shock breakouts – a shockwave and flash of light that rocks a massive star just before it explodes into a “supernova” – allow the stars to finally explode, spewing out all the heavy atoms that exist in the universe.
But actually watching that process occur and seeing how it progresses has proved elusive, leaving scientists guessing about exactly how it happens.
By sifting through three years of data collected by Nasa’s now half-broken Kepler space telescope, an international team of scientists have now seen the elusive shock breakout occur. The problem is, it seemed to happen in only one of two exploding stars observed.
In data collected in 2011, they found two supernovae begin, potentially capturing the crucial moment. However only one star seemed to have the shockwave. An author on the paper, Brad Tucker from the Australian National University, said that was a mystery. He said the shockwave was thought to ripple across the surface and actually allow the supernova to explode.
“We’ve always thought that this is the physical mechanism that allows the star to blow up,” he said. “So gravity collapses the core down, and once the pressure is too much, you create a neutron star or sometimes a black hole, the rest of the energy rebounds and causes the star to blow up.
“It’s been this fundamental thing that we’ve always thought occurs but we’ve never seen it take place.”
A terrorist attack has happened in Europe. Let the standard response begin…
Photo credit: The Spectator
By Douglas Murray
Well at least we all know the form by now. This morning Islamist suicide-bombers struck one of the few European capitals they haven’t previously hit in a mass-casualty terrorist attack.
The standard response now goes as follows. First the body parts of innocent people are flung across airport check-ins or underground trains. Briefly there is some shock. On social media the sentimentalists await the arrival of this atrocity’s cutesy hashtag or motif and hope it will tide them over until the piano man arrives at the scene of the attack to sing ‘Imagine there’s no countries’. Meantime someone will hopefully have said something which a lot of people can condemn as ‘inappropriate’. I see that the Telegraph columnist Allison Pearson was this morning’s Twitter miscreant, foolish enough to say in the wake of the Brussels attack that the EU might not make us very safe. One may agree or disagree with this sentiment, but Ms Pearson should have known that the only acceptable thing to do after a suicide bomber detonates beside the European Commission is to acclaim the Commission as one of the few entities able to keep us safe.
We will shortly move to the next phase, which is to find a good news story amid the rubble. Anything will do, but best of all is a Muslim good news story. After Paris it was swiftly reported that one of the suicide bombers at Stade de France had been turned away by a brave Muslim security guard. The story whizzed around the world before anyone could check whether it was true. It wasn’t. But people needed it to be. Not because Muslims don’t do good deeds, but because in the wake of any Islamist terrorist attack people need people opposed to the bombers to be Muslim and the bombers themselves not to be Muslim. Then the good Muslim can represent Islam while the bad Muslims can be said to have nothing to do with it.
Soon we will move to the next phase, during which broadcast media will ask questions that address no major points. So in the UK the government’s Communications Data Bill will get quite a lot of mentions. We will probably also have another round of the old discussion about Control Orders versus TPIMs. This will most likely be first raised by a Labour politician hoping to look tough. Everywhere on the media people will start to talk of ‘radicalisation’ as though it is something you can get from the water, and experts will claim insight into the ‘paths to extremism’. Nicky Morgan will announce that the Prevent agenda should be extended to encompass pre-kindergarten. A year later she will close some Quaker-run nursery.
Meanwhile other people will change the subject over to the question of Belgium’s unacceptably interventionist foreign policy. Others will get onto Israel-Palestine. At around the same time the Corbynite-wing of the Labour party will get onto their favourite subject which is not dead bodies in airports but people who have been looked at meanly on a bus while wearing a headscarf. By at least tomorrow the story of a savage ‘backlash’ (consisting mainly of stares and horrible things written on social media) will be being talked-up by all mainstream Muslim leaders. By Thursday no one will be talking about the victims.
Time for an Atheist Candidate
Photo credit: CNBC
By Herb Silverman
I recently wrote about the professed religious views of presidential candidates. I asked my favorite candidate, Bernie Sanders, at a public forum in South Carolina, if he would acknowledge being an atheist. Sanders, who almost always gives direct answers to questions, said, “Not gonna happen.” At least he didn’t lie about his religious beliefs, as many candidates do.
The most surprising and disappointing reaction to my attempt to “out” Bernie Sanders came from other atheists who support Sanders. They also assume that this Jewish socialist is an atheist, but they think he should stay in the closet.
Here are a few of the comments I heard: “You should know better than to think an open atheist could ever be elected president. Bernie does not want to commit political suicide by acknowledging he is an atheist. Bernie should wait to get elected, and then say he is an atheist. People who want political power better not reveal little quirks that would alienate a great majority of voters. Most religious Americans don’t believe in evolution, so they certainly wouldn’t vote for an atheist. This country is not yet ready to elect an atheist to high office.”
If these critics are correct that the country is not yet ready to elect an acknowledged atheist, then how can we change “not yet ready” to “ready?” If we do nothing, the country will never be ready. Our country was once not willing to elect African-Americans, women, gays, and other minority groups. The model for atheists is more similar to that of gays because African-Americans and women could never be closeted. Attitudes toward gays changed rapidly when people realized that their friends, neighbors, family members, and even famous people are gay. And so it can be for atheists. Here are two attitude-changing national organizations that aim to end the secrecy.
Openly Secular: Its purpose is to provide support and encouragement for atheists, agnostics, humanists, and other nonreligious people who feel they can’t be open about who they are. They provide resources to help secular people live full, honest, and open lives. Their goal is to eliminate discrimination and increase acceptance of the secular community. Their website contains dozens of short videos made by ordinary and extraordinary people from all backgrounds in all walks of life, describing why they became openly secular. Here is mine.
Freethought Equality Fund: This is a Political Action Committee (PAC) dedicated to expanding voter choices by backing the candidacy of open nontheists. The PAC supports candidates who want to protect the separation of religion and government and defend the civil liberties of secular Americans. The PAC also aims to dispel the bigoted notion that atheists are immoral and lack values. It is the first such PAC with a paid staff. (Disclosure: I’m an unpaid advisory board member.)
Both Openly Secular and the Freethought Equality Fund think the country is ready to elect nonreligious candidates. More than 20 percent of Americans now claim no religious identity, and the percentage is even higher among young people. Nonreligious Americans are one of the largest minorities in the United States, but you’d never know it because they have lacked political power. Interestingly, Congressman Barney Frank publicly came out as gay in 1987, but didn’t come out as an atheist until he left office.
New Atheism, Meet Existential Risk Studies
Photo credit: TheHumanist.com
By Phil Torres
While the New Atheist movement isn’t, and has never been, a monolithic phenomenon, its primary motivating idea can be reduced to a single statement, namely that religion is not merely wrong, but dangerous. In fact, religion is dangerous precisely because it’s wrong: it commands believers to act according to “moral” precepts and guidelines that are ultimately based on private revelations had by ancient prophets claiming special access to the supernatural. Put differently, religion is our very best instance of institutionalized bad epistemology, and this is what makes it unreasonable to accept. And when its doctrinal systems are put into practice, they often compromise our well-being and prosperity.
Copious evidence substantiates this contention. On the one hand, history is overflowing with bloody conflicts driven by antagonistic religious dogmas held by fanatics who cared more about the otherworldly than the worldly. And, as the 2014 Global Terrorism Index affirms, religious extremism constitutes the primary driver of terrorism around the world today. Even more, numerous empirical studies have shown that, to quote the sociologist Phil Zuckerman, secular people are “markedly less nationalistic, less prejudiced, less anti-Semitic, less racist, less dogmatic, less ethnocentric, less close-minded, and less authoritarian” than religious people. And the most secularized countries tend to be the happiest, the most peaceable (according to the Global Peace Index), and, as reported by the Economist’s think tank several years ago, the “best places to be born.” While Christopher Hitchens’ declaration that “religion poisons everything” might be somewhat exaggerated, religious belief is consistently associated with diminished levels of human flourishing.
But I believe that the New Atheist’s position is even more compelling than the New Atheists themselves have previously realized. Concomitant with the rise of the New Atheist movement about a decade ago, another field took shape in some of the top universities around the world, most notably Oxford and Cambridge. This field, called existential risk studies (or existential riskology), grew out of the innovative work of thinkers like John Leslie, Sir Martin Rees, Richard Posner, and Nick Bostrom. Its focus is a special kind of tragedy known as an existential risk, or a catastrophe resulting in either our extinction or a state of permanent and severe deprivation.
While humanity has always been haunted by a small number of improbable threats to our survival, such as asteroid/comet impacts, supervolcanoes, and pandemics (call these our “cosmic risk background”), advanced technologies are introducing a constellation of brand-new existential risks that humanity has never before encountered—and therefore has no track record of surviving. These risks stem largely from technologies like nuclear weapons, biotechnology, synthetic biology, nanotechnology, and even artificial superintelligence, which a growing number of scholars identify as the greatest (known) threat to the long-term survival of humanity. Add to this the ongoing slow-motion catastrophes of climate change and biodiversity loss that threaten our planetary spaceship with environmental ruination. While these two risks could genuinely bring about our extinction, they’re probably best described as “conflict multipliers” that will nontrivially raise the probability of other risk scenarios being realized, as state and non-state actors compete for land and dwindling resources.
Taking all of this into account, many riskologists believe that the probability of an existential catastrophe occurring in the foreseeable future is unsettlingly high. For example, last year the Bulletin of Atomic Scientists moved the minute hand of its Doomsday Clock (a metaphorical clock according to which midnight represents doom) from five minutes before midnight to a mere three minutes. And in January, Bulletin board members (including 2015 Humanist of the Year Lawrence Krauss) held a press conference to announce that despite the Paris climate agreement and the Iran nuclear deal, the hands of the clock would not move from their perilous position in 2016. As a point of reference, the furthest away from midnight that we’ve been since the Doomsday Clock was created in 1947 is seventeen minutes, at the close of the Cold War. And only once before, at the height of the Cold War, has the hand been closer than it currently is today.
Scientists Have Managed To Edit HIV Out Of Infected Cells
Photo credit:
HIV infects the immune systems CD4+ T-cells, which compromises the immune system and leads to the development of AIDs. 3Dme Creative Studio/Shutterstock
The last few years has seen a massive leap in terms of genome editing. With the development of the incredible CRISPR/Cas9 technique, never before have scientists been able to so easily and precisely identify, edit, or remove specific sections of DNA. This has allowed scientists to target particular mutations, giving hope that the cure for certain inherited diseases could be around the corner.
What Does Human Meat Taste Like? Man Cuts Off Part Of His Own Leg To Find Out, And Films The Whole Thing
Photo credit:
BBC/BritLab/YouTube
Ever wondered what human flesh tastes like? Perhaps with some fava beans and a nice Chianti?
Science presenter Greg Foot tries to get to the secret of what human flesh tastes like in this excerpt from BritLab for the BBC.
Glyptodonts Weren’t Just Armadillo Cousins, They Were Armadillos
Well-established by now on this blog is my love for and obsession with xenarthrans. So let it be a sign of my devotion to getting the upcoming issue of RNCSE out on time and full of awesome that I allowed not one but two xenarthran stories in the news to pass without comment. This then is the first of my xenarthran catch-up posts. The Wikimedia commons
story, which made the science news circuit in late February, stemmed from a short article in Current Biology (original is behind a paywall, but here is a summary). The superficial summary of the findings is that glyptodonts, my favorite group of extinct xenarthans, were giant armadillos. I’ll admit now that when I saw the headline I didn’t appreciate the newsworthiness of the result—didn’t we know that already? Thankfully, while trapped on a plane and cut off from the DC Eagle Cam for six hours the other day, I took the time to read the papers, because this is a very cool bit of research with, it turns out, a novel conclusion. Let’s dig in.
Within the awesomesauce clade Xenarthra is clade Cingulata, which includes armadillos, glyptodonts, and pampatheres. Of these, only armadillos are still living. I am not very familiar with pampatheres (a blind spot in my xenarthran knowledge!), but from what I gather, they were a group of large animals (but not as large as glyptodonts) distinguishable from armadillos and glyptodonts by the structure of their shell. No one ever suggested that these three groups of animals were anything but closest relatives, and if you look at them, you’ll see why. However, just how they were related hasn’t been well resolved. Which two of the three were closest cousins? No one really knew. Anatomy could only reveal so much. It seemed that to get to the bottom of this xenarthran mystery, DNA would be needed.
But if you’ll recall, two of the three groups of cingulates are extinct, and fossils, while unquestionably valuable, are not a great source of DNA. (Here in parenthetical quiet I will whisper the truth: they’re terrible.) But the relevant technology keeps improving, and more and more studies involving recovered ancient DNA have been appearing in recent years. The glyptodont researchers added to the library of fossil DNA fishing techniques by developing new “baits” for sequence-capture using reconstructed ancestral sequences. These new baits were designed to avoid picking up contaminants, which is a problem with ancestral DNA recovery—sometimes you get DNA but you can’t be sure you got DNA from the organism you were hoping for.
Reconstruction of Doedicurus (Nobu, CC BY 3.0 via Wikimedia commons)
The researchers reconstructed known sequences of ancestral xenarthran mitochondrial DNA. With that bait, they went fishing in a swirl of DNA bits and extracted from an 11,000 year old Doedicurus shell. (Doedicurus is a super cool spiked-tail glyptodont.) The bait attracts the matching complementary sequences, making it possible to pull out the DNA to which those sequences were attached. The result? Isolated snippets of ancestral glyptodont mitochondrial DNA, which can then be pieced together into a full mitochondrial DNA genome. (Maybe that's the equivalent of cleaning and gutting their catch.) Make sense?
Like a juicy worm, the new baits worked. Using this novel protocol, the researchers were able to reconstruct the entire mitochondrial DNA genome of a Doedicurus. (A quick refresher: mitochondria, the organelles in the eukaryote cell that convert sugars and oxygen to energy, have their own DNA, separate from the DNA found in the cell’s nucleus. So before you ask, no, we cannot clone glyptodonts based on this recovered DNA—not even close. I know; I’m sad, too.)
What do you do with an ancient mitochondrial genome once you have it? You compare it to others, of course! From this, they concluded that glyptodonts were actually nested within armadillos! What does that mean? (Not that armadillos are marsupials, silly.) It means that glyptodonts were actually armadillos themselves, most closely related to the fairy, giant, three-banded, and naked armadillos with which they form a clade newly dubbed the Glyptodontinae.
[image error]Three-banded armadillo (Hedwig, CC BY-SA 3.0 via Wikimedia commons)
Okay, so you may be wondering…so what? And I get that. Slight rearranging of twiglets on a phylogenetic tree is not everyone’s cup of tea. However, I find it superlatively cool that the team was able to extract the ancient DNA in the first place, let alone use it to resolve a phylogenetic puzzle. Moreover, it’s a great example of how DNA and morphology can—and should—work together to give us a clearer understanding of the history of life. Too often, the public is given the impression that DNA can solve all riddles and answer all questions. True, it can do more and more solving and answering with each passing year. However, this study was effective because the morphology had already gotten us 90% of the way home. Researchers knew where to look and which organisms to compare. And they used the DNA to confirm the results that morphology alone had supplied, not just in terms of relationships but also in terms of the timing of splitting events. Molecular dating put the divergence of glyptodonts and other armadillos at around 35 million years—which agreed fantastically well with the estimates made based on anatomy.
Also worthy of note is that the study altered how we think about glyptodont evolution. Glyptodonts have a completely fused shell, unlike the shells of armadillos and pampatheres that have moveable joints in their shells. Knowing what we now know, it’s possible to conclude that bendy shells came first, and that the solid nature of the glyptodont shell is a derived characteristic. It’s always tempting (though sometimes ill-advised) to ask the “well, why?” question, and in the present case the researchers came up with a hypothesis. They submit that perhaps the unmovable shell may have evolved in response to glyptodont gigantism. Perhaps, they say, it just wasn’t developmentally or functionally possible to have a bendy giant shell. Maybe; maybe not. Are there any experimentally minded xenarthraphiles out there who want to do a whole lot of research to test that hypothesis?
It seems the team is planning other lines of study which, to my absolute delight, involve extinct xenarthrans. My fingers—and doubtless Steve Bowden’s, too—are crossed that the giant ground sloth is up next.
Are you a teacher and want to tell us about an amazing free resource ? Do you have an idea for a Misconception Monday or other type of post? Have a fossil to share ? See some good or bad examples of science communication lately? Drop me an email or shoot me a tweet @keeps3.
ريتشارد دوكنز's Blog
- ريتشارد دوكنز's profile
- 106 followers
