Science news digest – 16th January 2013
In the science news this week, a genetic link between India and Australia, a newly discovered penguin colony meet their first humans, the death of an internet activist sparks open-access tribute, and finally… chimps show their generous side.
Genetic link between India and Australia
A genetic study has suggested that Australia experienced a wave of migration from India about 4,000 years ago, reported the BBC. Until now, it was believed that the continent has been mostly isolated after the first humans arrived about 40,000 years ago, until Europeans colonised the area in the 1800s.
However, genetic analysis of the DNA of Aboriginal Australians has shown that there has been some movement from India during this time.
The researchers also believe that the Indian migrants may have brought the dingo with them. Fossil records suggest that the wild dogs arrived in Australia at around the same time.
"For a long time, it has been commonly assumed that following the initial colonisation, Australia was largely isolated as there wasn't much evidence of further contact with the outside world," explained Prof Mark Stoneking, from the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany.
"It is one of the first dispersals of modern humans - and it did seem a bit of a conundrum that people who got there this early would have been so isolated."
The study compared the DNA of Aboriginal Australians with people from New Guinea, South East Asia, and India. This was done by pinpointing specific locations within the DNA, known as genetic markers, which could then be tracked to determine who was most closely related with whom.
They found a genetic association between New Guineans and Australians, which dates back to between 35,000 and 45,000 years ago. At this time, Australia and New Guinea were part of the same land mass, and this coincides with the arrival of the first humans.
However, there was also a significant amount of gene flow between India and Australia. Prof Stoneking said: "We have a pretty clear signal from looking at a large number of genetic markers from all across the genome that there was contact between India and Australia somewhere around 4,000 to 5,000 years ago."
Although this new study will not be able to describe the route taken by the Indians to reach Australia, it shows that the continent was not as isolated as was once thought.
Penguin colony receive first human visitors
A previously undiscovered colony of emperor penguins has been visited and photographed for the first time, reported the Guardian.
The colony of about 9,000 birds was discovered by scientists from the British Antarctic Survey from satellite images of Antarctica’s Princess Ragnhild coast.
Three experts from Belgium’s Princess Elizabeth Antarctica polar research station travelled to the site in early December.
The expedition leader, Alain Hubert, said: "I knew from last year's satellite study that there could potentially be an emperor colony east of Derwael ice rise.
"Because we were operating not far from this the satellite location, I decided to force the way and try to access this remote and unknown place.
"The surprise was even more than all I could have expected or dreamed about: I realised while counting the penguins that this was a very populated colony.
"It was almost midnight when we succeeded in finding a way down to the ice through crevasses and approached the first of five groups of more than a thousand individuals, three-quarters of which were chicks. This was an unforgettable moment."
Activist’s death sparks an open-access tribute online
Hundreds of researchers have been sharing PDFs of their papers on the social networking site, Twitter, this week as a tribute to Aaron Swartz, an internet freedom activist who committed suicide on Friday, reported New Scientist.
Swartz was facing hacking charges in the US after he downloaded nearly 5 million articles from the digital library JSTOR from the Massachusetts Institute of Technology’s network.
Swartz also helped to develop RSS and Reddit, two additions that have greatly increased sharing and openness on the internet. He played a major role in fighting the Stop Online Piracy Act, which aimed to give copyright holders greater control over the internet.
Some academics have now started to offer free versions of their work on Twitter using the hashtag #pdftribute in memory of Swartz. The papers are also being collected on the site pdftribute.net.
The hashtag was started by Jessica Richman, from University of Oxford, and Eva Vivalt, a development economist from the World Bank in Washington DC.
The origins of fair play
A study from Emory University in the US may have revealed the origins of humans’ generosity, according to the BBC.
The researchers tested a group of chimpanzees using an experiment known as the “ultimatum game”, where two chimps are given the opportunity to decide how to divide a portion of banana slices between themselves.
Traditionally, the game is used as a test of economics, where two people decide how to divide a sum of money. The first participant is given an amount and asked to make an offer to the other participant. If the second player accepts the offer, then the money is divided accordingly.
However, if they refuse the offer, then both players receive nothing. Ultimately, if the first participant makes a selfish offer, they run the risk of getting nothing.
The chimpanzees were shown a variation of the game, where coloured tokens were used to represent the reward.
"We tried to abstract it a little - to make it a bit like money," Dr Darby Proctor, the lead researcher, explained.
"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 the other.
If the second chimp accepted the token, both animals received their reward. Three pairs of chimps played the game, and the results revealed that the animals had a tendency to choose the token which gave a fair and equal share of the food between the chimps.
"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."