Curiosity taking a self-portrait. Image: Nasa
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Curiosity sniffs farts on Mars, could mean extinction of humanity

Fluctuations in methane gas in the Martian atmosphere, detected by the Curiosity rover, could mean that there's life living below the surface of Gale Crater. The implications could be surprising.

There's life on Mars! Maybe. Again. What's going on?

Nasa has announced that the Curiosity rover has detected spikes in methane concentration in the atmosphere within the Gale Crater. Over the last 20 months Curiosity has sampled the chemical makeup of the air around it a dozen times, finding that normally there are seven methane molecules per ten billion other air molecules (which on Mars is about 96 per cent carbon dioxide) - except on two occasions, where it jumped to ten times that. That's a big deal because methane doesn't just linger around; it's produced by some chemical process and then dissipates relatively quickly, so whatever's producing it must be doing it recurrently and frequently.

We all have experience with methane production (particularly around the Christmas season, with brussel sprouts on the table), but it's important to stress this isn't a definitive proxy for Martian life. Sure, it could be microbes, but it could also come from the reaction of the mineral olivine with water, as this Nasa infographic shows, and that's been the suspicion ever since methane was first detected in the atmosphere by astronomers in 2009. But we've always known that Mars' methane is unevenly distributed, and possibly seasonal, and that there are a number of alternative sources for it than bacteria "burping".

The announcement also included the news that the rock sample that Curiosity drilled into in May 2013 yielded further organic molecules when analysed, and also revealed important data about the history of the planet's water - and when it was lost. What we can really say here is that we have even more evidence to support the conclusion that Mars was habitable and Earth-like (or at least from the perspective of microbial life) billions of years in the past, but also that we don't know yet if it still is today.

Something we have to think about when we find life somewhere else - and we will find aliens, eventually, in centuries if necessary - is what the means for us, humanity, in the big picture. Statistically. Those of us who gamble might well consider it a bad omen.

There's this idea that there's a "Great Filter" which none, or very little, life gets through, on the cosmological scale. It was first outlined by economist Robin Hanson in 1996, and others have since refined it or challenged it, but basic premise is this: we haven't met aliens yet because all intelligent life capable of star travel is killed off before it spreads beyond its home star.

We know now that the number of planets far outnumbers the number of stars in the universe, and that it's therefore probable that there are billions upon billions of planets capable of hosting life. And, if life is like us, and works out how to colonise other planets and stars, we know that the amount of time it should take to colonise a large part of, say, a galaxy, should be short compared to galactic timescales - that is, if there's a lifeform that can colonise another star, it's reasonable to assume that it'll colonise almost all the stars it can in pretty short order, at a rate of a few centuries perhaps. So, if there are lots of Earth-like planets with (presumably) Earth-like intelligence on them, where the hell is everybody? (This is the famous Fermi paradox.)

The explanation Hanson and others have suggested is that somewhere, between the emergence of single-cellular life and interstellar travel, there's the Great Filter - many planets reach it, but few get through, because of asteroid strikes or runaway climate change or resource depletion or... anything we have yet to experience as a species. We can't see anybody else, and the universe feels like an empty place, because the cumulative probability of making it through every step - a safe planet where RNA appears and then single-celled life and then multi-celled and then the evolution of a tool-using lifeform that then develops interstellar travel - is so low as to be zero.

What makes the possibility that life evolved independently on Mars (especially multi-cellular life) so worrying from this perspective, then, is that it means the first few stages of that process are even easier than we thought - and that means getting beyond the stage we're at now must be much, much harder than we thought. The probability works out to tell us that we're at the stage of biological and cultural and technological development where we're wiped out before we take the next step.

There are, though, a dozen or more retorts to this: maybe intelligent life is intelligent enough not to have to colonise everywhere, or maybe it's intelligent to the extent that it's able to choose to remain invisible to us. But it's still a sobering thought that the thrilling discovery of alien life could be one of the last great moments in our species before a statistically-likely mishap hits us from left field.

Ian Steadman is a staff science and technology writer at the New Statesman. He is on Twitter as @iansteadman.

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Not just a one-quack mind: ducks are capable of abstract thought

Newborn ducklings can differentiate between objects that are the same and objects that are different, causing scientists to rethink the place of abstract thinking.

There’s a particular loftiness to abstract thought. British philosopher and leading Enlightenment thinker John Locke asserted that “brutes abstract not” – by which he meant anything which doesn’t fall under the supreme-all-mighty-greater-than-everything category of Homo sapiens was most probably unequipped to deal with the headiness and complexities of abstract thinking.

Intelligence parameters tail-ended by “bird-brained” or “Einstein” tend to place the ability to think in abstract ways at the Einstein end of the spectrum. However, in light of some recent research coming out of the University of Oxford, it seems that the cognitive abilities of our feathery counterparts have been underestimated.

In a study published in Science, led by Alex Kacelnik – a professor of behavioural psychology – a group of ducklings demonstrated the ability to think abstractly within hours of being hatched, distinguishing the concepts of “same” and “different” with success.

Young ducklings generally become accustomed to their mother’s features via a process called imprinting – a learning mechanism that helps them identify the individual traits of their mothers. Kacelnik said: “Adult female ducks look very similar to each other, so recognising one’s mother is very difficult. Ducklings see their mothers from different angles, distances, light conditions, etc, so their brains use every possible source of information to avoid errors, and abstracting some properties helps in this job.”

It’s this hypothesised abstracting of some properties that led Kacelnik to believe that there must be more going on with the ducklings beyond their imprinting of sensory inputs such as shapes, colours or sounds.

The ability to differentiate the same from the different has previously been used as means to reveal the brain’s capacity to deal with abstract properties, and has been shown in other birds and mammals, such as parrots, pigeons, bees and monkeys. For the most part, these animals were trained, given guidance on how to determine sameness and differences between objects.

What makes Kacelnik’s ducklings special then, as the research showed, was that they were given no training at all in learning the relations between objects which are the same and object which are different.

“Other animals can be trained to respond to abstract relations such as same or different, but not after a single exposure and without reinforcement,” said Kacelnik.

Along with his fellow researcher Antone Martinho III, Kacelnik hatched and domesticated mallard ducklings and then threw them straight into an experiment. The ducklings were presented pairs of objects – either identical or different in shape or colour – to see whether they could find links and relations between the pairs.

The initial pairs they were presented served as the imprinting ones; it would be the characteristics of these pairs which the ducklings would first learn. The initial pairs involved red cones and red cylinders which the ducklings were left to observe and assimilate into their minds for 25 minutes. They were then exposed to a range of different pairs of objects: red pyramid and red pyramid, red cylinder and red cube.

What Kacelnik and his research partner found was that the ducklings weren’t imprinting the individual features of the objects but the relations between them; it’s why of the 76 ducklings that were experimented with, 68 per cent tended to move towards the new pairs which were identical to the very first pairs they were exposed to.

Put simply, if they initially imprinted an identical pair of objects, they were more likely to favour a second pair of identical objects, but if they initially imprinted a pair of objects that were different, they would favour a second pair of differing objects similar to the first.

The results from the experiment seem to highlight a misunderstanding of the advanced nature of this type of conceptual thought process. As science journalist Ed Yong suggests, there could be, “different levels of abstract concepts, from simple ones that young birds can quickly learn after limited experience, to complex ones that adult birds can cope with”.

Though the research doesn’t in any way assume or point towards intelligence in ducklings to rival that of humans, it seems that the growth in scientific literature on the topic continues to refute the notions that human being as somehow superior. Kacelnik told me: “The last few decades of comparative cognition research have destroyed many claims about human uniqueness and this trend is likely to continue.”