Science news digest – 5th August 2013
In the news this week: evolution punishes the selfish, a brain-to-brain interface that lets humans control other animals with their thoughts, a blood test for Alzheimer’s, and finally, can you tell if your dog is happy?
Selfish people lose out in the long run
A new study finds that evolution does not favour the selfish, countering research that was widely reported last year. Using game theory, scientists at Michigan State University have discovered how selfish behaviour can create a disadvantage that leaves mean species out in the cold.
Much of the research in game theory, which is used to explore biology, politics and other areas, focuses on how and why we cooperate. In 2012, a research paper explained a newly discovered strategy called ‘zero-determinant’, which allowed players to gain a significant advantage by being selfish.
Scientists have been exploring cooperation using a game called the prisoner’s dilemma. In the scenario, two suspects are questioned for a crime in separate cells. Both are offered a deal for freedom if they inform on the other, imprisoning their opponent for six months, but only if the opponent chooses not to inform. If both inform on each other, they both get three months in prison, but if they remain silent they get one month each. Established thought stems from mathematician John Nash, who showed that the optimum strategy was not to cooperate, and the 2012 study concurred.
The Michigan researchers were not convinced, however, and ran a huge number of simulations to find out if zero-determinism would create a world filled with selfish beings, wiping out cooperation altogether. They ran hundreds of thousands of game scenarios, and found that although the strategy worked well against other selfish creatures, zero determinism appeared to be less successful with cooperative players.
"For many years, people have asked that if he [Nash] is right, then why do we see cooperation in the animal kingdom, in the microbial world and in humans," lead author Christoph Adami of Michigan State University told the BBC.
"The two prisoners that are interrogated are not allowed to talk to each other. If they did they would make a pact and be free within a month. But if they were not talking to each other, the temptation would be to rat the other out. Being mean can give you an advantage on a short timescale but certainly not in the long run - you would go extinct."
Brain-to-brain device allows humans to control rat’s tail by thinking
Scientists at Harvard Medical School have created a system that allows a human to control a rat’s tail just by thinking about it. The research, published in PLoS ONE, throws up numerous questions about the future of mind control technology.
Seung-Schik Yoo’s team have used a now-common method of reading the human mind, electroencephalography (EEG), and combined it with a new way of stimulating the brain, reports CNet. Focused ultrasound (FUS) directs acoustic energy towards a specific point, usually for heating and destroying diseased tissue, but the team found that FUS at lower energy levels can be used to stimulate brain tissue without killing it. This means that the mechanism used to control the rat’s brain is non-invasive.
The process works like this: the EEG detects whenever a human looks at a particular visual pattern, and sends a pulse of ultrasound to the area of the brain responsible for moving the rat’s tail. The ultrasound is administered from outside the body, so although the rat needs to be restrained, it does not require any surgical implants. Techniques such as deep brain stimulation involve the insertion of electrodes into the brain, but all surgery incurs certain risks, and a non-invasive approach is safer and quicker.
The paper explains that the human signal takes roughly 1.5 seconds to be processed and cause the rat’s tail to twitch. The next step for the researchers is to try and communicate more complex thoughts such as hunger, anger or sexual arousal. Beyond that, the computer-to-brain interface could be tested on humans, potentially creating the possibility for telepathic communication between humans. It’s clear that the technology will require extensive ethical consideration.
Blood test for Alzheimer’s is one step nearer
Alzheimer’s disease causes untold trauma to sufferers and their families, but early detection can help to soften the blow and give patients time to prepare for symptoms. The disease can start as long as a decade before symptoms arise. In the future, diagnostic tests could be the first step before treatment, but there is currently no definitive test, according to the BBC.
Now scientists at Saarland University in Germany are one step closer to creating a blood test to detect the disease. They started by analysing 140 small fragments of genetic code called microRNAs. They discovered that 12 microRNAs in the blood were present in different amounts in Alzheimer’s patients.
This is the basis of their test, which can determine whether a participant suffers from Alzheimer’s with an accuracy of 93%, according to the paper published in Genome Biology. Further research is needed to improve accuracy and make the test suitable for use in the clinic.
Dr Eric Karran, from the charity Alzheimer's Research UK, told the BBC: "This is an interesting approach to studying changes in blood in Alzheimer's and suggests that microRNAs could be playing a role in the disease. The findings highlight the importance of continuing research efforts to understand the contribution of microRNAs to Alzheimer's, but the translation of this into a blood test for Alzheimer's in the clinic is still some way off.
"A blood test to help detect Alzheimer's could be a useful addition to a doctor's diagnostic armoury, but such a test must be well validated before it's considered for use. We need to see these findings confirmed in larger samples and more work is needed to improve the test's ability to distinguish Alzheimer's from other neurological conditions."
Dogs communicate happiness with their brow
How do you tell if your dog is happy? Does it tell you with a wag of its tail? Research from Azabu University in Sagamihara, Japan, has found that dogs also use their face to show happiness. By attaching coloured markers to the faces of dogs, scientists discovered that dogs raise their eyebrows when they are happy, and lower their ears when they are uncertain, according to the Telegraph. Have a look at your dog’s eyebrows next time you arrive home to see if it really is happy to see you!