Tuesday, 29 January 2013

Dung Beetles, "Walking On The Milky Way" - [Article]

Illustration by '*venkman-project'

(New Scientist, 25, January 2013) - Ever look up at the stars and wonder if some bug-eyed creature is doing the same? It turns out at least one does: the dung beetle uses the glow of the Milky Way to navigate.

Once a beetle (Scarabaeus satyrus) has constructed its dung ball, it moves off in a straight line in order to escape from rival beetles as quickly as possible, lest they try and steal its carefully crafted ball. This behaviour doesn't sound complicated, but several years ago, Marie Dacke of Lund University in Sweden and colleagues showed that polarised light from the moon is important for dung beetles to keep to a straight line.

Then the researchers were surprised to find the insects were able to stay on course even on a moonless night. "We thought there was something wrong in our set-up," Dacke says.

The team allowed the beetles to crawl around the floor of a plain-walled cylindrical drum with an open top, meaning they could only use the night sky to orientate themselves. The researchers timed how long it took the beetles to reach the edge of the drum from the centre, and found that under a full moon, the insects took around 20 seconds on average; on a starry but moonless night, they took around 40 seconds.

But when beetles had a cardboard cap placed on them to prevent them from seeing the sky, they needed over two minutes, suggesting the stars were playing a role.

To test this, the team moved the experiment to a planetarium. By switching stars on and off, Dacke discovered that the glowing strip of the whole Milky Way was what guided the beetles' movement. "Before it was assumed insects could not use the stars because their eyes don't have the resolution to see them," she says. Navigating using the whole of the Milky Way does away with the need to see individual stars.

Dacke says the results suggest moths, locusts and other insects might navigate by the Milky Way, too. Her team is now looking at whether the beetles prefer to navigate by the moon or the Milky Way when both are on view.

Evolution Doesn't Always Mean The Most Badass - [Comic]

Sunday, 27 January 2013

An Old Wolf Can't Learn New Tricks, But Dogs Can - [Article]


(Science Daily, 17, Jan 2013) - Dogs and wolves are genetically so similar; it's been difficult for biologists to understand why wolves remain fiercely wild, while dogs can gladly become "man's best friend." Now, doctoral research by evolutionary biologist Kathryn Lord at the University of Massachusetts Amherst suggests the different behaviours are related to the animals' earliest sensory experiences and the critical period of socialization. Details appear in the current issue of Ethology.

Until now, little was known about sensory development in wolf pups, and assumptions were usually extrapolated from what is known for dogs, Lord explains. This would be reasonable, except scientists already know there are significant differences in early development between wolf and dog pups, chief among them timing of the ability to walk, she adds.

To address this knowledge gap, she studied responses of seven wolf pups and 43 dogs to both familiar and new smells, sounds and visual stimuli, tested them weekly, and found they did develop their senses at the same time. But her study also revealed new information about how the two subspecies of Canis lupus experience their environment during a four-week developmental window called the critical period of socialization, and the new facts may significantly change understanding of wolf and dog development.

When the socialization window is open, wolf and dog pups begin walking and exploring without fear and will retain familiarity throughout their lives with those things they contact. Domestic dogs can be introduced to humans, horses and even cats at this stage and be comfortable with them forever. But as the period progresses, fear increases and after the window closes, new sights, sounds and smells will elicit a fear response.

Through observations, Lord confirmed that both wolf pups and dogs develop the sense of smell at age two weeks, hearing at four weeks and vision by age six weeks on average. However, these two subspecies enter the critical period of socialization at different ages. Dogs begin the period at four weeks, while wolves begin at two weeks. Therefore, how each subspecies experiences the world during that all-important month is extremely different, and likely leads to different developmental paths, she says.

Lord reports for the first time that wolf pups are still blind and deaf when they begin to walk and explore their environment at age two weeks. "No one knew this about wolves, that when they begin exploring they're blind and deaf and rely primarily on smell at this stage, so this is very exciting," she notes.  She adds, "When wolf pups first start to hear, they are frightened of the new sounds initially, and when they first start to see they are also initially afraid of new visual stimuli. As each sense engages, wolf pups experience a new round of sensory shocks that dog puppies do not."

Meanwhile, dog pups only begin to explore and walk after all three senses, smell, hearing and sight, are functioning. Overall, "It's quite startling how different dogs and wolves are from each other at that early age, given how close they are genetically. A litter of dog puppies at two weeks are just basically little puddles, unable to get up or walk around. But wolf pups are exploring actively, walking strongly with good coordination and starting to be able to climb up little steps and hills."

These significant, development-related differences in dog and wolf pups' experiences put them on distinctly different trajectories in relation to the ability to form inter-species social attachments, notably with humans, Lord says. This new information has implications for managing wild and captive wolf populations, she says.

Her experiments analysed the behaviour of three groups of young animals: 11 wolves from three litters and 43 dogs total. Of the dogs, 33 border collies and German shepherds were raised by their mothers and a control group of 10 German shepherd pups were hand-raised, meaning a human was introduced soon after birth.

At the gene level, she adds, "the difference may not be in the gene itself, but in when the gene is turned on. The data help to explain why, if you want to socialize a dog with a human or a horse, all you need is 90 minutes to introduce them between the ages of four and eight weeks. After that, a dog will not be afraid of humans or whatever else you introduced. Of course, to build a real relationship takes more time. But with a wolf pup, achieving even close to the same fear reduction requires 24-hour contact starting before age three weeks, and even then you won't get the same attachment or lack of fear."

Wednesday, 16 January 2013

The Wild Attenborough - [Comic]

[Source: Bird and Moon]

Children 'May Grow Out of Autism' - [Article]

Is a label of autism lifelong? And is this child a cannibal? 

(BBC Health, 16, Jan 2013) - Some young children accurately diagnosed as autistic lose their symptoms and their diagnosis as they get older, say US researchers.  The findings of the National Institutes of Health study of 112 children appears to challenge the widely held belief that autism is a lifelong condition.

While not conclusive, the study, in the Journal of Child Psychology and Psychiatry, suggests some children might possibly outgrow autism.

But experts urge caution.

Much more work is needed to find out what might explain the findings.

Dr Deborah Fein and her team at the University of Connecticut studied 34 children who had been diagnosed with autism in early childhood but went on to function as well as 34 other children in their classes at school.

On tests - cognitive and observational, as well as reports from the children's parents and school - they were indistinguishable from their classroom peers. They now showed no sign of problems with language, face recognition, communication or social interaction.

For comparison, the researchers also studied another 44 children of the same age, sex and non-verbal IQ level who had had a diagnosis of "high-functioning" autism - meaning they were deemed to be less severely affected by their condition.

It became clear that the children in the optimal outcome group - the ones who no longer had recognisable signs of autism - had had milder social deficits than the high-functioning autism group in early childhood, although they did have other autism symptoms, like repetitive behaviours and communication problems, that were as severe.

The researchers went back and checked the accuracy of the children's original diagnosis, but found no reason to suspect that they had been inaccurate.

The researchers say there are a number of possible explanations for their findings.
It might be that some children genuinely outgrow their condition. Or perhaps some can compensate for autism-related difficulties.

Dr Thomas Insel, director of the National Institute of Mental Health, said: "Although the diagnosis of autism is not usually lost over time, the findings suggest that there is a very wide range of possible outcomes.
"Subsequent reports from this study should tell us more about the nature of autism and the role of therapy and other factors in the long term outcome for these children."

It could be that autism cannot always be accurately defined or diagnosed, particularly since the condition affects people in different ways.

Indeed, experts have disagreed about what autism is.

The American Psychiatric Association is currently revising its diagnostic manual - the "bible" for doctors that lists every psychiatric disorder and their symptoms.

Instead of using the current terms of autistic disorder, Asperger's disorder, childhood disintegrative disorder and PDD-NOS (pervasive developmental disorder not otherwise specified), people will be given an umbrella diagnosis of "autism spectrum disorder".

And their impairments will be reduced to two main areas - social communication/interaction and restricted, repetitive patterns of behaviour, interests, or activities.

Most diagnoses in the UK are based on the International Classification of Diseases (ICD), published by the World Health Organization, which is up for revision in 2015.

According to the National Autistic Society, more than one in every 100 people, more than 500,000 people in all, in the UK have autism.

About a fifth, an estimated 106,000, are school-aged children.

Dr Judith Gould, director of the National Autistic Society's Lorna Wing Centre for Autism, said: "Autism is a lifelong disability affecting the way that people communicate and interact with others.

"This study is looking at a small sample of high functioning people with autism and we would urge people not to jump to conclusions about the nature and complexity of autism, as well its longevity.

"With intensive therapy and support, it's possible for a small sub-group of high functioning individuals with autism to learn coping behaviours and strategies which would 'mask' their underlying condition and change their scoring in the diagnostic tests used to determine their condition in this research.

"This research acknowledges that a diagnosis of autism is not usually lost over time and it is important to recognise the support that people with autism need in order to live the lives of their choosing."

She said getting a diagnosis could be a critical milestone for children with autism and their families, often helping parents to understand their children better and helping them to support their children in reaching their full potential.

Tuesday, 15 January 2013

The Chimp Ultimatum: Study Reveals Origins of Human Fair Play - [Article]

The Ultimatum Game: When the first chimp takes a token and
 passes it to its partner, this represents an "offer"

(BBC Science, 15, Jan 2013) The human tendency to share may have more ancient evolutionary routes than previously thought.

This is according to a study of the performance of chimpanzees in a test called the "ultimatum game".

Traditionally, the game is employed as a test of economics; two people decide how to divide a sum of money.

This modified game, in which two chimps decided how to divide a portion of banana slices, seems to have revealed the primates' generous side.

The study, published in Proceedings of the National Academy of Sciences, was part of an effort to uncover the evolutionary routes of why we share, even when it does not make economic sense.

Scientists say this innate fairness is an important foundation of co-operative societies like ours.

Lead researcher Darby Proctor from the Yerkes National Primate Research Center at Emory University, US, explained why she and her colleagues chose to use the ultimatum game, which has been used in the past to illustrate the human tendency to share.

During the game, one participant is given an amount of money and asked to "make an offer" to the second player. If that second player accepts the offer, the money is divided accordingly.

But, if the second player refuses that offer, both players receive nothing. This is the basis of the fairness versus economics quandary; if the first player proposes a selfish, unequal offer, the affronted recipient might refuse.

And this is exactly what happens in humans. Although it makes economic sense to give away as little as possible and accept any offer that's proposed, people usually make roughly equal, or "fair" offers, and tend to refuse unequal or "unfair" offers.

Dr Proctor and her colleagues trained their chimp participants to play a similar game, using coloured tokens to represent a reward.

"We tried to abstract it a little - to make it a bit like money," Dr Proctor explained.

A previous attempt to test merit-based sharing among our closest living relatives, the chimpanzees, was published in a 2007 study published in the journal Science. Researchers using the ultimatum game found that chimps would take any reward - no matter what share they were offered. But the authors of this study say this may have been because the chimps were directly offered food which they found "difficult to resist".

While children appear to be prepared to share with a new playmate, non-human primates seem to limit their altruism to close kin and mates. But it is not simply the case that the more intelligent the species the more altruistic they are. Recent research on sharing published in PNAS in social primates revealed that capuchins and marmosets were some of the most "giving" primates - commonly offering food rewards to other group members

Before we feel too superior to our primate cousins, our capacity to be spiteful appears to be ours alone. A 2007 published in PNAS study found chimpanzees, unlike humans, do not retaliate against personally harmful actions. Being spiteful is a human trait

"We trained them with two different tokens.

"If they took [a white token], they would be able to split the food equally, and taking the other [blue] token meant that the first chimp would get more food than the partner."

The researchers presented both tokens to the first chimp, which would then choose one and offer it to its partner.

As with the human version of the game, if the partner accepted the token, both animals received their reward.

Three pairs of chimps played this game, and the results revealed that the animals had a tendency to offer a fair and equal share of the food reward.

In another experiment, the team repeated the test with 20 children between the ages of two and seven. They discovered that both young children and chimps "responded like humans typically do" - tending to opt for an equal division of the prize.

"What we're trying to get at is the evolutionary route of why humans share," explained Dr Proctor.

"Both chimps and people are hugely cooperative; they engage in cooperative hunting, they share food, they care for each other's offspring.

"So it's likely that this [fairness] was needed in the evolution of cooperation.

"It seems to me that the human sense of fairness has been around in primates for at least as long as humans and chimps have been separated."

Dr Susanne Schultz from the University of Manchester said the study was very interesting and showed "the potential for chimps to be aware of fair offers".

"It is interesting that changing the study design - primarily by not using food rewards it seems - one can elicit fairness behaviour in chimps," she told the BBC.

She added though that is was not clear that the chimps completely understood the design of the game and that, with just six chimps involved in the study, further evidence would be needed to show clearly that chimps had a natural tendency towards fairness.

Monday, 14 January 2013

Animals and Their People - [Photography]

A ranger inspects a 10-day-old baby elephant at
Sarah Deu conservation response unit in Sampoiniet, Aceh Jaya, Indonesia

(The Big Picture, 29, Oct 2012) - We keep them as pets, although which species maintains the upper paw in that relationship is sometimes in doubt. We drive them to the brink of extinction, and then make desperate attempts to bring them back. We tend them as livestock, display them in zoos, and research them in labs and in the wild. Our lives are intertwined with those of animals, and better for it. Gathered here are images of that furry interface. 

36 photos in collection

Are Crows Mind Readers ... Or Just Stressed Out? - [Article]

"Soon... my Lego castle will be complete!
Your people intelligence is no match for my bird intelligence"

(ScienceNOW, 10, Jan 2013) - Are crows mind readers? Recent studies have suggested that the birds hide food because they think others will steal it — a complex intuition that has been seen in only a select few creatures. Some critics have suggested that the birds might simply be stressed out, but new research reveals that crows may be gifted after all.

Cracks first began forming in the crow mind-reading hypothesis last year. One member of a research team from the University of Groningen in the Netherlands spent 7 months in bird cognition expert Nicola Clayton’s University of Cambridge lab in the United Kingdom studying Western scrub jays, a member of the crow family that is often used for these studies. The Groningen team then developed a computer model in which “virtual jays” cached food under various conditions.

In PLOS ONE, they argued that the model showed the jays’ might be moving their food—or recaching it—not because they were reading the minds of their competitors, but simply because of the stress of having another bird present (especially a more dominant one) and of losing food to thieves. The result contradicted previous work by Clayton’s group suggesting that crows might have a humanlike awareness of other creatures’ mental states—a cognitive ability known as theory of mind that has been claimed in dogs, chimps, and even rats.

In the new study, Clayton and her Cambridge graduate student James Thom decided to test the stress hypothesis. First, they replicated earlier work on scrub jays by letting the birds hide peanuts in trays of ground corn cobs—either unobserved or with another bird watching—and later giving them a chance to rebury them. As in previous studies, the jays recached a much higher proportion of the peanuts if another bird could see them: nearly twice as much as in private, the team reports online today in PLOS ONE.

Then came the stress test. First, Thom and Clayton gave the jays trays with the ground cobs but no food to hide in them—a so-called “sham” session. Then, in a second session, they gave the birds new hiding trays and bowls of peanuts to hide. When the jays were done, the experimenters removed the trays and stole all of the peanuts. Finally, after a short break, the researchers gave each bird yet another round of food, a new tray to hide it in, and one of the trays it had seen earlier: either the sham tray or the ransacked “pilfer” tray. The jays had 10 minutes for recaching.

If the Groningen model was correct, Thom and Clayton argue, the stress of discovering that food was missing from the pilfer tray ought to drive jays to cache more peanuts than those presented with the sham tray. In fact, there was no difference, even though corvids have excellent memories for hidden food and remarkable abilities to find it again. The hypothesis that jays have theory of mind remains on the table, Thom says.

Thom and Clayton have “definitely shown that scrub recaching is not as simple as the [Groningen] model presents it,” says Elske van der Vaart, lead author of the Groningen team’s earlier report, who is now at the University of Amsterdam. But she argues that there is still room for doubt about what the results mean. For example, the sham condition—in which the jays had no food to cache—could have stressed the birds as much as the stolen peanuts in the pilfer condition did.

Amanda Seed, an animal cognition researcher at the University of St. Andrews in the United Kingdom, says the Groningen model’s failure to predict the birds’ caching behavior in the new experiments could “bring the model down like a pack of cards.” But researchers still have to rule out other possible explanations, she says. For example, the birds given pilfered tray may have noticed the missing peanuts too late to affect their overall caching rate, or they may have spent much of their time looking for the missing nuts instead of hiding the new ones. The Cambridge and Groningen groups are planning more work with both real and “virtual” birds to see what is really going on. “I applaud them for rising to the challenge,” Seed says.

Sunday, 13 January 2013

How Language and Culture Matter in Learning - [Video]

(GeeksAreSexy, 13, Jan 2013) - Phdcomics have released a new video, this one from the Language and Linguistics department at the University of Melbourne in Australia. Sara Ciesielski is producing a thesis called “Language Development and Socialization in Sherpa” and here it is…in 2 minutes:

[Via PhDcomics)

Wednesday, 9 January 2013

Why do fingers wrinkle in water? It helps us grip things that are wet new research finds - [Article]

"Each finger is like a mini grumpy cat, beautiful in it's own way"

(BBC Science-Environment, 9, Jan 2013) - Science may be getting closer to explaining those prune-like fingers and toes we all get when we sit in a hot bath too long.  UK researchers from Newcastle University have confirmed wet objects are easier to handle with wrinkled fingers than with dry, smooth ones.  They suggest our ancestors may have evolved the creases as they foraged for food in wet vegetation or in streams.

Their experiments are reported in the Royal Society journal Biology Letters.

These involved asking volunteers to pick up marbles immersed in a bucket of water with one hand and then passing them through a small slot to be deposited by the other hand in a second container.

Volunteers with wrinkled fingers routinely completed the task faster than their smooth-skinned counterparts.  The team found there was no advantage from ridged fingers when moving dry objects. This suggests that the wrinkles serve the specific function of improving our grip on objects under water or when dealing with wet surfaces in general.

For a long time, it was assumed that the wrinkles were simply the result of the skin swelling in water, but recent investigations have actually shown the furrows to be caused by the blood vessels constricting in reaction to the water, which in turn is a response controlled by the body's sympathetic nervous system.

That an active system of regulation is at work led scientists into thinking there must be some deeper evolutionary justification for the ridges.

"If wrinkled fingers were just the result of the skin swelling as it took up water, it could still have a function but it wouldn't need to," said Dr Tom Smulders, from Newcastle's Centre for Behaviour and Evolution.  The tests involved handling wet objects with wrinkled and un-wrinkled fingers

"Whereas, if the nervous system is actively controlling this behaviour under some circumstances and not others, it seems less of a leap to assume there must be a function for it, and that evolution has selected it. And evolution wouldn't have selected it unless it conferred some sort of advantage," he told BBC News.

US-based researchers were the first to propose that the wrinkles might act like the tread on tyres, and even demonstrated how the patterns in the skin resembled those of run-off channels seen on the sides of hills.

What the Newcastle team has now done is confirm that prune-like fingers are indeed better at gripping wet objects.

"We have tested the first prediction of the hypothesis - that handling should be improved," Dr Smulders said.
"What we haven't done yet is show why - to see if the wrinkles remove the water, or whether it's some other feature of those wrinkles such as a change in their stickiness or plasticity, or something else. The next thing will be to measure precisely what's happening at that interface between the objects and the fingers."

Our ancestors might not have played with wet marbles, but having better gripping fingers and feet would certainly have been advantageous as they foraged for food along lake-shores and by rivers.

It would be interesting to see, observed Dr Smulders, just how many other animals displayed this trait - in particular, in primates.

"If it's in many, many primates then my guess is that the original function might have been locomotion through wet vegetation or wet trees. Whereas, if it's just in humans that we see this then we might consider something much more specific, such as foraging in and along rivers and the like."

Tuesday, 8 January 2013

Human Kindness Also Found in Bonobos - [Article]

"I love you generic orange fruit stuff, never leave me"

(NYTimes.com, 7, Jan 2013) - Bonobos will happily share their food with a stranger, and even give up their own meal — but only if the stranger offers them social interaction, evolutionary anthropologists at Duke University report in the journal PLoS One. The researchers, Jingzhi Tan and Brian Hare, say their findings may shed light on the origins of altruism in humans.

Along with chimpanzees, bonobos are among the closest primates to humans. Chimpanzees, however, do not display similar behaviour toward strangers.

“If you only studied chimps you would think that humans evolved this trait of sharing with strangers later,” Mr. Tan said. “But now, given that bonobos do this, one scenario is that the common ancestor of chimps, humans and bonobos had this trait.”

The subjects were all orphaned bonobos at the Lola ya Bonobo sanctuary in the Democratic Republic of Congo. In one phase of the study, bonobos were given a pile of food, then given the opportunity to release a stranger or a group mate (or both) from other rooms.

The bonobos chose to release strangers and share their food. Not only that, but the just-released bonobo would then release the third.

“This was shocking to us because chimpanzees are so xenophobic,” Mr. Tan said. “They won’t approach a stranger unless they outnumber them.”

The apes did have a limit — they would not share their own food when no social interaction was involved.
They were, however, willing to help a stranger get food even without social interaction. Mr. Tan compared this to certain human acts of kindness.

“It’s like when you donate money and you don’t tell people,” he said, “so there’s no way for you to get any benefit.”