The Economist: For decades scientists have known that birds’ ability to navigate with great accuracy over long distances, in some cases migrating from one side of the world to the other, relies on a magnetic sense that humans lack. Experiments with homing pigeons performed in the early 1970s found that attaching a magnet disrupted their ability to orientate themselves. Since then, research has intensified into the precise mechanism of birds’ magnetic sense. So how does it work?

Scientists have focused their attention in three areas: the beak, the inner ear and the eyes. Birds’ beaks contain tiny grains of magnetite, a form of iron oxide which is easily magnetised, and is known to be involved in magnetic sensing in bacteria. But when David Keays of the Institute of Molecular Pathology in Vienna examined the beaks of 200 pigeons, the results were surprising. He found that the magnetite grains were mostly located in macrophages, which are sort of biological garbage collectors that wander around the body, rather than in specialised sense cells. This strengthened the case that birds’ magnetic sense resides not in their beaks, but in their inner ears. Dr Keays and his colleagues changed tack, and earlier this year they reported that they had found tiny concentrations of iron in the neurons of a pigeon’s inner ear.

Case closed? Not quite. The latest research, published in June, suggests the beak does have a role to play after all. [Continue reading…]

BBC News reports: Plants have a built-in capacity to do maths, which helps them regulate food reserves at night, research suggests.

UK scientists say they were “amazed” to find an example of such a sophisticated arithmetic calculation in biology.

Mathematical models show that the amount of starch consumed overnight is calculated by division in a process involving leaf chemicals, a John Innes Centre team reports in e-Life journal.

Birds may use similar methods to preserve fat levels during migration.

The scientists studied the plant Arabidopsis, which is regarded as a model plant for experiments.

Overnight, when the plant cannot use energy from sunlight to convert carbon dioxide into sugars and starch, it must regulate its starch reserves to ensure they last until dawn.

Experiments by scientists at the John Innes Centre, Norwich, show that to adjust its starch consumption so precisely, the plant must be performing a mathematical calculation – arithmetic division.

“They’re actually doing maths in a simple, chemical way – that’s amazing, it astonished us as scientists to see that,” study leader Prof Alison Smith told BBC News. [Continue reading…]

Michael Pollan writes: I can tell you the exact date that I began to think of myself in the first-person plural — as a superorganism, that is, rather than a plain old individual human being. It happened on March 7. That’s when I opened my e-mail to find a huge, processor-choking file of charts and raw data from a laboratory located at the BioFrontiers Institute at the University of Colorado, Boulder. As part of a new citizen-science initiative called the American Gut project, the lab sequenced my microbiome — that is, the genes not of “me,” exactly, but of the several hundred microbial species with whom I share this body. These bacteria, which number around 100 trillion, are living (and dying) right now on the surface of my skin, on my tongue and deep in the coils of my intestines, where the largest contingent of them will be found, a pound or two of microbes together forming a vast, largely uncharted interior wilderness that scientists are just beginning to map.

I clicked open a file called Taxa Tables, and a colorful bar chart popped up on my screen. Each bar represented a sample taken (with a swab) from my skin, mouth and feces. For purposes of comparison, these were juxtaposed with bars representing the microbiomes of about 100 “average” Americans previously sequenced.

Here were the names of the hundreds of bacterial species that call me home. In sheer numbers, these microbes and their genes dwarf us. It turns out that we are only 10 percent human: for every human cell that is intrinsic to our body, there are about 10 resident microbes — including commensals (generally harmless freeloaders) and mutualists (favor traders) and, in only a tiny number of cases, pathogens. To the extent that we are bearers of genetic information, more than 99 percent of it is microbial. And it appears increasingly likely that this “second genome,” as it is sometimes called, exerts an influence on our health as great and possibly even greater than the genes we inherit from our parents. But while your inherited genes are more or less fixed, it may be possible to reshape, even cultivate, your second genome. [Continue reading…]

The Telegraph reports: A study has shown that people are able to precisely identify a range of emotions in dogs from changes in their facial expressions.

The research showed that volunteers could correctly spot when a dog was happy, sad, angry, surprised or scared, when shown only a picture of the animal’s face, suggesting that humans are naturally attuned to detecting how animals are feeling.

Dr Tina Bloom, a psychologist who led the research, said: “There is no doubt that humans have the ability to recognise emotional states in other humans and accurately read other humans’ facial expressions. We have shown that humans are also able to accurately – if not perfectly – identify at least one dog’s facial expressions.

“Although humans often think of themselves as disconnected or even isolated from nature, our study suggests that there are patterns that connect, and one of these is in the form of emotional communication.”

The study, published in the journal Behavioural Processes, used photographs of a police dog named Mal, a five-year-old Belgian shepherd dog, as it experienced different emotions. [Continue reading…]

Immortality has always struck me as a terrible idea — the most extreme expression of self-infatuation. Out with the old and in with the new seems like a universal law and a good one. It turns out, however, that that’s not always the case.

Nathaniel Rich writes: After more than 4,000 years — almost since the dawn of recorded time, when Utnapishtim told Gilgamesh that the secret to immortality lay in a coral found on the ocean floor — man finally discovered eternal life in 1988. He found it, in fact, on the ocean floor. The discovery was made unwittingly by Christian Sommer, a German marine-biology student in his early 20s. He was spending the summer in Rapallo, a small city on the Italian Riviera, where exactly one century earlier Friedrich Nietzsche conceived “Thus Spoke Zarathustra”: “Everything goes, everything comes back; eternally rolls the wheel of being. Everything dies, everything blossoms again. . . .”

Sommer was conducting research on hydrozoans, small invertebrates that, depending on their stage in the life cycle, resemble either a jellyfish or a soft coral. Every morning, Sommer went snorkeling in the turquoise water off the cliffs of Portofino. He scanned the ocean floor for hydrozoans, gathering them with plankton nets. Among the hundreds of organisms he collected was a tiny, relatively obscure species known to biologists as Turritopsis dohrnii. Today it is more commonly known as the immortal jellyfish.

Sommer kept his hydrozoans in petri dishes and observed their reproduction habits. After several days he noticed that his Turritopsis dohrnii was behaving in a very peculiar manner, for which he could hypothesize no earthly explanation. Plainly speaking, it refused to die. It appeared to age in reverse, growing younger and younger until it reached its earliest stage of development, at which point it began its life cycle anew.

Sommer was baffled by this development but didn’t immediately grasp its significance. (It was nearly a decade before the word “immortal” was first used to describe the species.) But several biologists in Genoa, fascinated by Sommer’s finding, continued to study the species, and in 1996 they published a paper called “Reversing the Life Cycle.” The scientists described how the species — at any stage of its development — could transform itself back to a polyp, the organism’s earliest stage of life, “thus escaping death and achieving potential immortality.” This finding appeared to debunk the most fundamental law of the natural world — you are born, and then you die.

One of the paper’s authors, Ferdinando Boero, likened the Turritopsis to a butterfly that, instead of dying, turns back into a caterpillar. Another metaphor is a chicken that transforms into an egg, which gives birth to another chicken. The anthropomorphic analogy is that of an old man who grows younger and younger until he is again a fetus. For this reason Turritopsis dohrnii is often referred to as the Benjamin Button jellyfish.

Yet the publication of “Reversing the Life Cycle” barely registered outside the academic world. You might expect that, having learned of the existence of immortal life, man would dedicate colossal resources to learning how the immortal jellyfish performs its trick. You might expect that biotech multinationals would vie to copyright its genome; that a vast coalition of research scientists would seek to determine the mechanisms by which its cells aged in reverse; that pharmaceutical firms would try to appropriate its lessons for the purposes of human medicine; that governments would broker international accords to govern the future use of rejuvenating technology. But none of this happened. [Continue reading…]

Mark Rowlands writes: When I became a father for the first time, at the ripe old age of 44, various historical contingencies saw to it that my nascent son would be sharing his home with two senescent canines. There was Nina, an endearing though occasionally ferocious German shepherd/Malamute cross. And there was Tess, a wolf-dog mix who, though gentle, had some rather highly developed predatory instincts. So, I was a little concerned about how the co-sharing arrangements were going to work. As things turned out, I needn’t have worried.

During the year or so that their old lives overlapped with that of my son, I was alternately touched, shocked, amazed, and dumbfounded by the kindness and patience they exhibited towards him. They would follow him from room to room, everywhere he went in the house, and lie down next to him while he slept. Crawled on, dribbled on, kicked, elbowed and kneed: these occurrences were all treated with a resigned fatalism. The fingers in the eye they received on a daily basis would be shrugged off with an almost Zen-like calm. In many respects, they were better parents than me. If my son so much as squeaked during the night, I would instantly feel two cold noses pressed in my face: get up, you negligent father — your son needs you.

Kindness and patience seem to have a clear moral dimension. They are forms of what we might call ‘concern’ — emotional states that have as their focus the wellbeing of another — and concern for the welfare of others lies at the heart of morality. If Nina and Tess were concerned for the welfare of my son then, perhaps, they were acting morally: their behaviour had, at least in part, a moral motivation. And so, in those foggy, sleepless nights of early fatherhood, a puzzle was born inside of me, one that has been gnawing away at me ever since. If there is one thing on which most philosophers and scientists have always been in agreement it is the subject of human moral exceptionalism: humans, and humans alone, are capable of acting morally. Yet, this didn’t seem to tally with the way I came to think of Nina and Tess.

The first question is whether I was correct to describe the behaviour of Nina and Tess in this way, as moral behaviour. ‘Anthropomorphism’ is the misguided attribution of human-like qualities to animals. Perhaps describing Nina and Tess’s behaviour in moral terms was simply an anthropomorphic delusion. Of course, if I’m guilty of anthropomorphism, then so too are myriad other animal owners. Such an owner might describe their dog as ‘friendly’, ‘playful’, ‘gentle’, ‘trustworthy’, or ‘loyal’ — a ‘good’ dog. On the other hand, the ‘bad’ dog — the one they try to avoid at the park — is bad because he is ‘mean’, ‘aggressive’, ‘vicious’, ‘unpredictable’, a ‘bully’, and so on. Nor are these seemingly moral descriptions entirely useless. On the contrary, it is a valuable skill to be able to assess these descriptions when an unfamiliar dog is bearing down on you in the street. If I’m guilty of anthropomorphism, so too, it seems, are many others.

Many scientists (and more than a few philosophers) would have no hesitation in accusing perhaps several billion people of such delusional anthropomorphism. A growing number of animal scientists, however, are going over to the dark side, and at least flirting with the idea that animals can act morally. In his book Primates and Philosophers (2006), the Dutch primatologist Frans de Waal has argued that animals are at least capable of proto-moral behaviour: they possess the rudiments of morality even if they are not moral beings in precisely the way that we are. This was, in fact, Charles Darwin’s view, as developed in The Descent of Man. In a similar vein, the American biologist Marc Bekoff has being arguing for years that animals can act morally, and his book Wild Justice (2009) provides a useful summary of the evidence for this claim. Perhaps scientists such as Darwin, de Waal and Bekoff are also guilty of anthropomorphism? The evidence, however, would suggest otherwise. [Continue reading…]

Adam Rogers poses some interesting questions about how we understand intelligence, but the observations he describes about slime molds pose an array of other questions. For instance, although a slim mold doesn’t possess a brain as a distinct organ, what might this organism’s aptitude in network formation tell us about the way neural networks are formed? Is it possible that these molds don’t so much lack a brain but rather that they are more like a brain with no body? (And forgive this off of the top of my head speculation. I know nothing about slime molds and not much more about brains.)

David P. Barash writes: Providing room and board to other life-forms doesn’t only compromise one’s nutritional status (not to mention peace of mind), it often reduces freedom of action, too. The technical phrase is “host manipulation.”

Take the tapeworm Echinococcus multilocularis, which causes its mouse host to become obese and sluggish, making it easy pickings for predators, notably foxes, which — not coincidentally — provide an optimal environment for the tapeworm to move into the next phase in its life cycle.

Sometimes the process is truly strange. For example, a kind of fluke known as Dicrocoelium dentriticum does time inside a snail, then an ant, followed by a sheep. Ensconced within an ant, some of the resourceful worms migrate to their host’s brain, where they manage to rewire its neurons, essentially hijacking its body.

The manipulated ant, in response to Dicrocoelium’s demands, then climbs to the top of a blade of grass and waits patiently and conspicuously until it is consumed by a grazing sheep. Once in its desired happy breeding ground, the worm releases its eggs, which depart with a healthy helping of sheep poop, only to be consumed once more by snails, which eventually excrete the immature worms for another generation of unlucky ants to consume.

It may be distressing to those committed to “autonomy,” but such manipulators have inherited the earth. Including us. [Continue reading…]

NPR reports: Scientists Wednesday unveiled the first catalog of the bacteria, viruses and other microorganisms that populate every nook and cranny of the human body.

Researchers hope the advance marks an important step towards understanding how microbes help make humans human.

The human body contains about 100 trillion cells, but only maybe one in 10 of those cells is actually — human. The rest are from bacteria, viruses and other microorganisms.

“The human we see in the mirror is made up of more microbes than human,” said Lita Proctor of the National Institutes of Health, who’s leading the Human Microbiome Project.

“The definition of a human microbiome is all the microbial microbes that live in and on our bodies but also all the genes — all the metabolic capabilities they bring to supporting human health,” she said.

These microbes aren’t just along for the ride. They’re there for a reason. We have a symbiotic relationship with them — we give them a place to live, and they help keep us alive. [Continue reading…]

The following article looks at the harmful effects of excessive hygiene and while it’s clearly directly relevant to America’s hand-sanitizing cleanliness-obsessed culture, the fear of germs is itself symptomatic of a wider culture of fear.

In our hunger to feel safe we have lost an understanding of the healthiness of insecurity and the pathology of safety. A society that craves constant safety can never grow up. It ends up becoming literally and metaphorically allergic to life.

Sedeer at Inspiring Science writes: Since moving to Finland, I’ve become accustomed to asking guests whether they have any allergies before I prepare dinner. I grew up in the developing world where allergies and asthma seem to be much less common than they are here; in fact, various studies have found higher rates of allergy and autoimmune conditions in developed than developing countries. One explanation for this is the “hygiene hypothesis,” which proposes that excessive hygiene early in life can affect the development of the immune system and result in allergic conditions and autoimmune diseases in later life. In a recent study appearing in Science, a team of scientists in Germany and the United States present evidence supporting the hygiene hypothesis and the importance of an early challenge to the immune system.

The researchers tested this idea in mice, which are commonly used as a model system to study the human immune response; they compared the immune systems and responses of germ-free (GF) mice, which were completely free of any microorganisms, and specific pathogen-free (SPF) mice, which had normal gut microbiota but were free of pathogens. The researchers measured the level of invariant Natural Killer T (iNKT) cells, which are an important part of the immune system, and found that the germ-free mice had more iNKT cells in their colon and lungs than their SPF counterparts. In addition to playing a vital role in our immune response, iNKT cells have also been implicated in several autoimmune conditions; the GF mice were more susceptible to induction of asthma and colitis (an autoimmune bowel inflammation), perhaps due to the increased quantity of iNKT cells. Although allowing the adult germ-free mice to be recolonized by microbes didn’t reduce their iNKT levels or their susceptibility to asthma or colitis, recolonization of pregnant GF mice just before delivery did lead to normal iNKT levels and reduced susceptibility in their offspring. Simply having microbiota wasn’t enough; the microbes had to be present at the right developmental stage in order to properly regulate the immune response. [Continue reading…]