Life on Venus claim faces strongest challenge yet

Two papers have dealt a fresh blow to the idea that Venus’s atmosphere might contain phosphine gas — a potential sign of life. In one study, researchers analysed data from one of the telescopes used to make the phosphine claim and could not detect the gas’s spectral signature. In the other, they calculated how gases would behave in Venus’s atmosphere and concluded that what the original team thought was phosphine is actually sulphur dioxide, a gas that is common on Venus and is not a sign of possible life. Still, the case isn’t closed yet. The new studies argue against the presence of phosphine, but can’t entirely rule it out.

The largest genome of any animal sequenced so far

The Australian lungfish (Neoceratodus forsteri) has the largest animal genome ever sequenced. The fish has a whopping 43 billion base pairs, around 14 times longer than the human genome — although most of its genome is made up of non-coding and repeating regions. A genomic analysis confirms that the surface-breathing fish are the closest living relatives of land vertebrates that last shared a common ancestor around 420 million years ago.

The forces that squeeze and pull life into shape

An embryo develops from a sphere of cells thanks, in part, to the forces that squeeze, bend and tug the growing animal into shape. Even when it reaches adulthood, its cells will continue to respond to pushing and pulling — by each other and from the environment. Yet how bodies and tissues take form remains one of the most important, and still poorly understood, questions of our time. Researchers have begun to define the mechanisms by which cells sense, respond to and generate forces using innovative tools and techniques, both in vitro and in whole animals.

Pulsars hint at sea of gravitational waves

Astronomers might have spied their first hint of gravitational waves made by merging supermassive black holes. For more than a decade, the NANOGrav collaboration has been monitoring radio waves from 45 spinning stars, known as pulsars. Tiny deviations in the arrival times of the waves could reveal the cumulative ripples in space-time caused by merging supermassive black holes across the Universe. An analysis of more than 12 years of data shows preliminary evidence for the effect.

Cuttlefish think ahead, ‘marshmallow test’ reveals

Eat one marshmallow now — or wait a few minutes and get two? This famous behavioural test is supposed to distinguish between impulsive children and those more likely to think through their actions — and thus, do better in academic life. Now, scientists have given a similar test to cuttlefish, The New York Times reports. Replacing the marshmallow with a shrimp, researchers gave the molluscs the option to eat two shrimp now — or eat one shrimp with the promise of an extra reward. Most of the cuttlefish chose the latter, researchers report in Royal Society Open Science. The find suggests that — like people — these molluscs can delay gratification if they think it will pay off in the long run.

Bean plants show signs of intent

Research suggests that at least one type of plant – the french bean – may be more sentient than we give it credit for: namely, it may possess intent.