Monday, 19 August 2013

Altruism or manipulated helping? Altruism may have origins in manipulation - [Article]

(, 19, Aug 2013) - Manipulation is often thought of as morally repugnant, but it might be responsible for the evolutionary origins of some helpful or altruistic behaviour, according to a new study.

Journal article: Evolution of manipulated behavior (apologies, article not live at time of publishing)

In evolutionary biology, manipulation occurs when an individual, the manipulator, alters the behaviour of another individual in ways that is beneficial to the manipulator but may be detrimental to the manipulated individual. Manipulation not only occurs in humans and animals but also at the cellular level, such as among cells in a multicellular organism, or in parasites, which can alter the behaviour of their hosts. 

Consider the case of the parasitic roundworm (Myrmeconema neotropicum), which once ingested by the tropical ant (Cephalotes atratus) in Central and South America, causes the ant to grow a bright red abdomen, mimicking berries. This bright abdomen constitutes a phenotype manipulated by the roundworm. Birds eat the "berries," or infected ants, and then spread the parasite in their droppings, which are subsequently collected by foraging Cephalotes atratus and fed to their larva, and the cycle of manipulated behaviour begins anew.

In the study published this week in the journal American Naturalist, the researchers developed a mathematical model for the evolution of manipulated behaviour and applied it to maternal manipulation in eusocial organisms, such as ants, wasps, and bees, which form colonies with reproductive queens and sterile workers. In the model, mothers produce two broods, and they manipulate the first-brood offspring to stay in the maternal site and help raise the second brood. 

Mothers can do this by disrupting the offspring's development in some way, for example through poor feeding or aggressive behaviour. Manipulated offspring of the first-brood stay and help to raise the second brood. Alternatively, first-brood offspring can resist manipulation and leave.

The researchers show that an offspring's resistance to manipulation may often fail to evolve, if the costs of resistance are high. In a sense, then, helping or altruistic behaviour is coerced through manipulation.

"The evidence in so-called primitive eusociality, where helping is often coerced through aggression or differential feeding, appears consistent with these results," said lead author Mauricio Gonzalez-Forero, who conducted the study while a graduate research assistant at the National Institute for Mathematical and Biological Synthesis.

Tuesday, 13 August 2013

What is dyslexia? But more importantly, why is it special?

(TEDEDUCATION, 13, August 2013) - Dyslexia affects up to 1 in 5 people, but the experience of dyslexia isn't always the same. This difficulty in processing language exists along a spectrum -- one that doesn't necessarily fit with labels like "normal" and "defective." Kelli Sandman-Hurley urges us to think again about dyslexic brain function and to celebrate the neurodiversity of the human brain.

Lesson by Kelli Sandman-Hurley, animation by Marc Christoforidis

Saturday, 10 August 2013

Contagious Yawning in Dogs and Humans: Are dogs more empathetic towards their owners?

(National Geographic, 8, August 2013) - Pets yawn more in response to owners' yawns than strangers', study says.

Dog owners who claim their pets know their feelings may be on to something: A new study shows that canines yawn more in response to their owners' yawns than they do to strangers' yawns.

That suggests dogs are "emotionally connected" to people, study leader Teresa Romero of the University of Tokyo said in a statement.

Scientists already knew that dogs sometimes yawn when they see people yawn, but it was unclear if that was considered a form of empathy or mild stress, as yawning can be caused by anxiety.

So Romero and her team set up an experiment in which 25 pet dogs watched both their owners and strangers yawn or pretend to yawn. (Read about why people yawn.)

The team ruled out stress when researchers saw no significant differences in the dogs' heartbeats during the experiments, according to the study, published August 7 in the journal PloS ONE.

Not only did the dogs in the study yawn more in response to their owners' yawns, they also yawned less when they saw fake yawns from their owners or from strangers, suggesting they were exhibiting true contagious yawning.

Contagious yawning occurs in humans, chimpanzees, baboons, and dogs.

In a similar study published last year, scientists found that people yawn more in response to the yawns of people they care about most.

In the case of people, scientists suspect that contagious yawning is a form of empathizing with people experiencing a feeling, which—in the case of yawning—usually means stress, anxiety, boredom, or fatigue.

Elisabetta Palagi, of the Institute of Cognitive Sciences and Technologies in Rome, noted that the study is the first time that scientists have shown contagious yawning occurring between different species.

"This could be the result of a long process of domestication," said Palagi, who wasn't involved in the study.  "Once more," she said, the study "demonstrates that dogs are capable of empathic abilities toward humans."

Tuesday, 6 August 2013

Dolphins recognise their old friends even after 20 years of being apart

(The Independent – 7, August 2013) - New study shows that the mammals have the longest social memory of any non-human species

Dolphins are able to remember one another's signature calls for at least 20 years making it the longest memory for "faces" among animals - perhaps even surpassing the ability of people to remember one another from their appearances alone.

Every dolphin has a unique whistle which is used as a signature call and stays with them unchanged throughout life. These identifying noises are even more reliable than the facial features used by people to recognise each other, which notoriously change over time.

Now a study has shown that when dolphins have been separated for 20 years or more they are still able to distinguish the whistle call of a former close companion from a host of other calls emitted by complete strangers, scientists said.

This kind of "social memory" surpasses the recognition abilities of elephants, primates and all other intelligent animals that have been studied in this way, said Jason Bruck, who carried out the work whilst studying for is PhD at the University of Chicago.

"This research shows that dolphins have the potential for lifelong memory for each other regardless of relatedness, sex or duration of association. This is the first study to show that social recognition can last for at least 20 years in a nonhuman species," Dr Bruck said.

"This shows us an animal operating cognitively at a level that's very consistent with human social memory. This is the kind of study you can only do with captive groups where you know how long the animals have been apart. To do a similar study in the wild could be almost impossible," he said.

The study, published in the journal Proceedings of the Royal Society of London B, involved collecting the recorded signature whistles of 53 different bottlenose dolphins living at six different facilities, from the Brookfield Zoo near Chicago to Dolphin Quest in Bermuda.

The dolphins at these sites are part of a captive-breeding programme and they have periodically spent time together going back many years, complete with fully-verified records.

During the study, Dr Bruck would play a recording of signature whistles of a stranger that a dolphin had never heard before. After repeating the call many times, the dolphin would quickly show signs that it is bored with the sound of another dolphin it had never met, he said.

Dr Bruck then introduced the call of a dolphin they had once known, and measured its response and behaviour. "When they hear a dolphin they know, they often quickly approach the speaker playing the recording. At times they will hover around, whistle at it, try to get it to whistle back," Dr Bruck said.

In one notable example, for instance, a female named Allie living at Brookfield Zoo recognised and responded to a recorded call of female called Bailey, now living in Bermuda, which had shared a pool with Allie 20 years and six months previously when they both lived at Dolphin Connection in Florida Keys, he said.

Dolphins are thought to live for about 20 years on average in the wild, although they are known to live as long as 45 years in captivity. It is possible that they social memory for signature whistles could last their lifetime, Dr Bruck said.

This is the longest, scientifically-tested social memory in animals, matched only by the anecdotal reports of elephants being able to recognise their mothers after 20 years of separation.

A study published earlier this year by researchers at the University of St Andrews found that dolphins not only recognised each other by their whistles but often mimic a close companion's unique whistle in an attempt to get them to respond.

"We know they use these signatures like names, but we don't know if the name stands for something in their minds the way a person's name does for us. We don't know yet if the name makes a dolphin picture another dolphin in its head," Dr Bruck said.