Victory to the Shaggy

Carpet shark swallows a bamboo shark whole (courtesy Tom Mannering)

We like to believe that victory belongs to the sleek and the strong.  But sometimes being shaggy and obscure works better.  Daniela Ceccarelli and David Williamson, from the  Australian Research Council’s Centre of Excellence for Coral Reef Studies, were doing research on the Great Barrier Reef when they spotted the spectacle of one shark swallowing another whole.

Bamboo sharks, looking as slick and smooth as an Apple product, forage for food by nosing into nooks and crannies along the bottom.  Carpet sharks, by contrast, are shaggy, camouflaged creatures that lie on the bottom and do nothing.  (Think of them as Microsoft products.)

But when dinner comes to them, they snap it up.

The Soft, Slow, Deadly Flight of Owls

Owls need to wing down through the dark almost silently, to hear–and avoid being heard by–their prey.  [Update:  This amazing footage shows the moments before impact.] They have to be good because a barn owl, for instance, needs to find and eat about six vole-sized rodents a night.  The secret of their extraordinary stealth lies in their ability to fly slowly, according to  Thomas Bachmann, from the Technical University Darmstadt in Germany.  He  presented his study of barn owl wings at the Society for Integrative and Comparative Biology’s annual meeting in Charleston, South Carolina.  BBC Nature reports:

To find out how they managed to fly so slowly and quietly, Dr Bachmann examined the birds’ wings in minute detail.

He examined the plumage and took 3-D medical scans of their skeletal structure.

The wings’ most important features, he explained, were the high curvature or “camber” … This curvature means that each wing beat produces more lift.

Air flow is accelerated over the upper surface the curved wing. “So the pressure drops,” he said. “[And] the wing is sucked upwards into the lower pressure on the upper wing surface.”

The fine feathery fringes of each wing also help silence the owl’s flight

The feathery edges of each wing are also extremely fine – reducing any loud turbulence during flight, explained Dr Bachmann.

“Friction noise between single feathers is also reduced [by] their velvety surface,” he told BBC Nature.

In fact, Dr Bachmann explained, “all the body parts of the owl are covered by very dense plumage – owls have more feathers than other similarly sized birds”.

This soft, dense plumage absorbs other sounds the birds make as they fly.

It turns out Bachmann is interested in barn owl flight mainly as a model for biomimicry in

Wake up, Lysenko, Tell Lamarckists the News

In an article being published tomorrow in Cell, scientists have demonstrated that an acquired trait can be inherited, without any DNA involvement.  It’s the second time in recent days that scientists have hinted that Lamarckism may be more than wishful thinking.

The idea that an organism can pass on  to its offspring  traits acquired during its lifetime was an early theory of evolution, put forward by the eminent French naturalist Jean-Baptiste Lamarck (1744-1829).  The idea fell into disrepute after the 1859 Darwin-Wallace discovery of evolution by natural selection.   But it became a deeply dangerous idea–and Soviet national policy–in the hands of a twentieth-century follower of Lamarck, Trofim Lysenko.  He argued, among other things, that he could soak wheat in frigid water and alter its DNA to make future generations more resistant to the harsh Russian winters.  Under Stalin, criticism of Lysenkoism could get legitimate scientists arrested or even killed.

But now researchers are focusing on factors outside the DNA that may alter the expression of certain genes, and it seems that an individual can acquire changes in how these factors function and pass those changes on to subsequent generations. Last week, Australian scientists described a preliminary study in mice, not yet published in a peer-reviewed journal, suggesting that  obese Dads can pass on a tendency to obesity to their offspring.  The researchers even suggested that prospective dads should consider losing a few pounds before trying for kids.  (No harm in that, but, hey, lose it for your own sake.)

The new study from Cell is of course peer-reviewed.  It’s about acquired immunity to disease, a subject with potential for profound evolutionary effects.  But for now the researchers mostly stick to their study animal,  a worm.  Here’s the press release:

Columbia University Medical Center (CUMC) researchers have found the first direct evidence that an acquired trait can be inherited without any DNA involvement. The findings suggest that Lamarck, whose theory of evolution was eclipsed by Darwin’s, may not have been entirely wrong.

The study is slated to appear in the Dec. 9 issue of Cell.

“In our study, roundworms that developed resistance to a virus were able to pass along that immunity to their progeny for many consecutive generations,” reported lead author Oded Rechavi, PhD, associate research scientist in biochemistry and molecular biophysics at CUMC. “The immunity was transferred in the form of small viral-silencing agents called viRNAs, working independently of the organism’s genome.”

In an early theory of evolution, Jean Baptiste Larmarck (1744-1829) proposed that species evolve when individuals adapt to their environment and transmit those acquired traits to their offspring. For example, giraffes developed elongated long necks

One Place Trophy-Hunting Lions Seems to Work

The December issue of Atlantic Monthly includes my Dispatch on trophy hunting of lions in Namibia:

We were crossing on foot through a scrubby patch of African wilderness when the guide casually noted that all the usual prey animals seemed to have gone elsewhere, a hint of lions in the neighborhood. This particular neighborhood, he added informatively, was home to a pride known for being “Full of shit.  Ballsy.  They don’t run away from people, the way lions usually do.”

The standard protocol, when hikers and lions bump into each other in the African bush, is for the lions to run, with the dominant male lion fleeing first. (That business about noble lion kings sacrificing themselves for family turns out to be one of the bigger, ballsier lies ever told about the male gender.) The females may stick around briefly, to snarl and show their teeth while the cubs also exit. Sometimes, a lioness will make a stiff-legged charge, skidding to a stop close enough to scatter sand on your shoes. And that’s generally as bad as it gets (though alternate endings are always possible). “Never run,” the guide advised. “Unless I tell you to.”  Discreetly peeing your pants is permitted.

That day, sadly or otherwise, our lions did not rouse themselves, and I was reduced to the standard tourist pastime of watching lions from an open game-drive vehicle. Lumbering diesels do not make the lions skittish, oddly. They lift their heads as if to say, “Oh, those wankers,” then flop back down in the dust and fall asleep.

What brought me on my visit early this year to South Africa and Namibia was the continuing controversy over the idea of using trophy hunting as a tool for lion conservation. The lion population in Africa has declined by at least a third over the past 20 years, due to

If It Bleeds, It Misleads

Images of child soldiers reinforce the idea that warfare is getting worse

We tend to think the world is caught up an endless and ever worsening round of bloody warfare.  But in his new book The Better Angels of Our Nature, Stephen Pinker argues that the opposite is true.  The Guardian recently headlined its excerpt with a clever twist on an old newspaper rubric:  “If it Bleeds, It Misleads”:

Why the gloom? Partly it’s the result of market forces in the punditry business, which favour the Cassandras over the Pollyannas. But mainly, I think, it comes from the innumeracy of our journalistic and intellectual culture. If we don’t keep an eye on the numbers, the programming policy “If it bleeds, it leads” will feed the cognitive short cut “The more memorable, the more frequent”, and we will end up with what has been called a false sense of insecurity.

The pessimism has been inspired by “new wars” involving guerrillas and paramilitaries that plague the developing world, symbolised by images of Kalashnikov-toting teenagers. It has been stoked by the widely repeated (and completely bogus) meme that at the beginning of the 20th century 90% of war deaths were suffered by soldiers and less than 10% by civilians, but by the end of the century these proportions had been reversed. It has fed on the claim that the world learned nothing from the Holocaust, and that genocides are as common as ever. And of course it has been redoubled by the threat of terrorism, which has been said to pose an “existential threat” to western countries, having the capacity to “do away with our way of life” or to end “civilisation itself”.

Each of these scourges continues to take a toll in human lives. But it’s only recently that political scientists have tried to measure how big a toll it is, and they have reached a surprising conclusion: all these kinds of killing are in decline. Battle deaths per 100,000 of the world population have fallen from 300 during the height of the second world war to the teens in the postwar years, single digits during the cold war, and less than one in the 21st century.

The deliberate killing of civilians has shown a similar bumpy yet downward trajectory. And other than in the war zones of Iraq and Afghanistan, deaths from terrorism in the past decade were far lower than they were in the 1970s and 1980s, with their hijackings and bombings by countless revolutionary fronts, leagues, brigades and factions. A mental model in which the world has a constant allotment of violence – so that every ceasefire is reincarnated somewhere else as a new war, and every interlude of peace is just a time-out in which martial tensions build up and seek release – is factually mistaken.

It’s not easy to see the bright side in the world today, where the remnants of war continue to cause tremendous misery. The effort to quantify the misery can seem heartless, especially when it undermines claims that are serving as effective propaganda for raising money and attention. But there is a moral imperative in getting the facts right, and not just because truth is better than error.

The discovery that fewer people are dying in wars all over the world can thwart cynicism among compassion-fatigued newsreaders who might otherwise think that poor countries are irredeemable hellholes. And a better understanding of what drove the numbers down can steer us towards doing things that make people better off, rather than congratulating ourselves on how morally sophisticated we are.

The argument that humans are born to cooperate, to make love, not war, is of course hardly new with Pinker.  Primatlogist Frans de Waal, among others, has made the case repeatedly, and my book The Ape in the Corner Office also emphasized our tendency to exaggerate the importance of conflict.

Mommy, Who’s for Dinner Tonight?

Natalie Angier writes today about animal cannibalism, starting with research  by Richard Shine at the University of Sydney in Australia  about cane toad tadpoles gobbling up cane toad eggs:

Significantly, the tadpoles weren’t simply hungry for a generic omelette. Reporting in the journal Animal Behaviour, Dr. Shine and his co-workers showed that when given a choice between cane toad eggs and the similar-looking egg masses of other frog species, Rhinella tadpoles overwhelmingly picked the cannibal option. Oh, little cane toads lacking legs, how greedily you snack on pre-toads packed in eggs!

Life after metamorphosis brought scant relief from fraternal threats. The scientists also demonstrated that midsize cane toads wriggle digits on their hind feet to lure younger cane toads, which the bigger toads then swallow whole. “A cane toad’s biggest enemy is another cane toad,” Dr. Shine said. “It’s a toad-eat-toad world out there.”

Rhinella’s brutal appetite is among a string of recent revelations of what might be called extreme or uncanny cannibalism, when one animal’s determination to feed on its fellows takes such a florid or subversive turn that scientists are left, as Mark Wilkinson of the Natural History Museum in London put it, “gobsmacked” by the sight.

There are males that demand to be cannibalized by their lovers and males that seek to avoid that fate by stopping midcourtship and hammily feigning rigor mortis. There are mother monkeys that act like hipster zombies, greeting unwanted offspring with a ghoulish demand for brains; and there are infant caecilians — limbless, soil-dwelling amphibians — that grow fat by repeatedly skinning their mother alive.

In the past, animal cannibalism was considered accidental or pathological: Walk in on a mother rabbit giving birth, and the shock will prod her to eat her bunnies. Now scientists realize that cannibalism can sometimes make good evolutionary sense, and for each new example they seek to trace the selective forces behind it.

Why do cane toad tadpoles cannibalize eggs? Researchers propose three motives. The practice speeds up maturation; it eliminates future rivals who, given a mother toad’s reproductive cycle, are almost certainly unrelated to you; and it means exploiting an abundant resource that others find toxic but to which you are immune.

“We’re talking about a tropical animal that was relocated to one of the driest places on earth,” Dr. Shine said. “Cannibalism is one of those clever tricks that makes it such a superb colonizer and a survival machine.”

You can read the full article, in which she describes male black widow spiders being eaten by the females after sex as “arachinirvana”  here.  I think it would be nerve-wracky-nirvana, no?

Listening to Alvin the Chipmunk as if Your Life Depends on it

It probably isn’t too surprising that birds deciding where to  nest actually listen for the sound of their major predators, and avoid those areas.  But I am always interested in new examples of the ways one species eavesdrops on another.  And I am genuinely surprised that chipmunks eat birds (ALVIN, how could you!).  Finally, it seems curious that Texas Tech scientists would be doing field research in the Hudson River Valley, and publishing their results in a British journal.

How provincial of me:

Newswise — Ground-nesting birds face an uphill struggle to successfully rear their young, with many eggs and chicks falling prey to predators.

However, two researchers at Texas Tech University have found that some birds eavesdrop on their enemies, using this information to find safer spots to build their nests. The study – one of the first of its kind – was published this week in the British Ecological Society’s Journal of Animal Ecology.

Ovenbirds (Seiurus aurocapilla) and veeries (Catharus fuscescens) both build their nests on the ground, running the risk of losing eggs or chicks to neighboring chipmunks that prey on

Sliming Osama

Under the sea: Osama makes new friends

This morning, I received a kind note from a reader, who found herself thinking oddly about Osama bin Laden after reading my book Spineless Wonders: Strange Tales from the Invertebrate World:

I just read Spineless Wonders in December, and enjoyed it very much.  Some of the creatures described were new to me, and I was amazed to find myself feeling sympathetic for the tarantulas.  However, the book led to a most unpleasant flashback when I awoke this morning, to the radio news announcing that the body of Osama bin Laden had been “buried at sea”.

My first coherent thought was not about peace or justice or the war on terrorism.  It was, “Hagfish!!!”

I’m afraid that in this case, I wish the hagfish well, and hope they will get some protein and profit from the deceased.

Thank you very much for your outstanding writing; I am looking forward to reading your other titles.

Hagfish, for those of you who have never had the strange pleasure of making their acquaintance, are scavengers on the ocean bottom.   Sometimes, fishermen encounter them in their catch, and here’s what I wrote in Spineless Wonders:

It is a disheartening sight for fishermen, touching some source of horror beyond mere economic loss.  One fisheries expert has attributed this horror to the slime itself:  “Being worthless … the hag is an unmitigated nuisance, and a particularly loathesome one owing to its habit of pouring out slime from its mucous sacs in quantity out of all proportion to its small size.  One hag, it is said, can easily fill a 2-gallon bucket, nor do we think this any exaggeration.”

But a far graver problem with slime eels, it seems to me, is that they make the idea of burial at sea so much less appealing.  Once having seen them, seafarers must suffer forever from foreboding that if they go down with the ship (or without it), slime eels will be waiting for them at the bottom.  Martin Cruz Smith employed this idea to fine effect in his novel, Polar Star, in which a Soviet murder victim returns from the bottom in a trawler net.  As investigators examine a knife wound in the victim’s gut, they notice a protruding “length of intestine, purplish-gray and slick …” which gradually becomes recognizable as a slime eel:  “The eel’s head, an eyeless stump with fleshy horns and a puckered mouth, whipped from side to side against Zina Patiashvili’s stomach; then the entire eel, as long as an arm, slid seemingly forever out of her, twisted in mid air …” and landed at the examining physician’s feet.

This scene is a figment of Smith’s imagination.  No one has ever found a human corpse being scavenged from within by slime eels.  In truth, most researchers believe that even fish corpses are a relative rarity in the diet of slime eels, which are more likely to subsist on worms, shrimp, and other small sea-bottom creatures.  But it is at least conceivable that hollowed-out shipwreck victims have at times drifted across the bottom like Michelangelo’s self-portrait as a sack of skin on the ceiling of the Sistine Chapel …

And now we can hope that Osama bin Laden is meeting this fate, in his element among the slime eels.

Tough Love for Bambi?

 

The last eastern cougar shot in the state of Vermont

A week or two back, when the snow was a foot deep and food was scarce, I had 18 white tail deer in  my yard on the Connecticut coast.  So what’s the answer to deer overpopulation in the U.S. Northeast?

Sorry, it’s now officially extinct.  The U.S. Fish and Wildlife Service has just removed the  eastern cougar from its endangered species list, says Mark McCullough, a biologist there, because years of searching have turned up no evidence of its survival:

A breeding population of eastern cougars would almost certainly have left evidence of its existence, he said. Cats would have been hit by cars or caught in traps, left tracks in the snow or turned up on any of the hundreds of thousands of trail cameras that dot Eastern forests.

But researchers have come up empty.

The private Eastern Cougar Foundation, for example, spent a decade looking for evidence. Finding none, it changed its name to the Cougar Rewilding Foundation last year and shifted its focus from confirming sightings to advocating for the restoration of the big cat to its pre-colonial habitat. The wildlife service said it has no authority under the Endangered Species Act to reintroduce the mountain lion to the East.

The promising news is that the eastern cougar may actually be genetically identical to its western siblings, and they are rapidly expanding their range back eastward.  If it happens, that could make running in the woods a lot more interesting for the deer (and maybe for us, too) and it might help restore a more natural balance of species.  It may sound a little tough on poor Bambi.  But scientific evidence demonstrates that species–and entire ecosystems–are better off when top predators are around to do their regrettable business.

Head Man in the Boneyard

The celebrated dinosaur guy Jack Horner appears this Sunday on 60 Minutes, and that reminded me of when I visited him for Time Magazine back in 1990.  (The article didn’t mention that on my first day out bone-hunting with him, jet lag caught up with me.  So I lay down in the middle of the high desert, on a bed of loose sharks’ teeth and triceratops fan fragments, and fell promptly asleep.)

Somewhere in eastern Montana, in the rolling, eroded hills known as the Hell Creek formation, paleontologist Jack Horner sips a beer and looks down at the most complete Tyrannosaurus rex ever unearthed. It lies on its left side, its neck twisted back pitiably. Horner’s crew has just exposed a section of pelvic bone to its first sunset in 65 million years, and someone remarks on the redness of the bone, like smoked bacon.

“It’s the comet,” says Horner, with a deep nod.

“That’s why it’s smoked,” his crew chief says.

Well, O.K., maybe not. Have a beer, sit down in the gray sandstone grit, but do not attempt to reopen the great debate over whether the dinosaurs were wiped out at the end of the Cretaceous period by a huge comet or a vast cloud of volcanic dust or any of 80-odd other proposed killers, all of which Horner spurns. He has a rubber stamp that says, WHO GIVES A SHIT WHAT KILLED THE DINOSAURS? Horner cares about how they lived.

Over the past decade, his ideas on this subject, based on a series of extraordinary finds, have helped rescue dinosaurs from the abstract realm of monsters, enabling people to view them for the first time as real animals. These theories have earned such respect in the scientific community that Horner, who flunked out of college seven times and was driving a truck in the family gravel business only 15 years ago, now heads