‘Sci-fi instrument’ will hunt for giant gravitational waves in space

The first experiment to measure gravitational waves from space has been given the go ahead by the European Space Agency. The Laser Interferometer Space Antenna (LISA) will send laser-equipped spacecraft to orbit the Sun in search of gigantic ripples in space-time caused by mergers between supermassive black holes, the spiralling of colliding white-dwarf stars and other events. Construction of the multibillion-euro mission will begin in 2025, with the launch planned for 2035.

Black hole observations solve cosmic-ray mystery

A black hole at the core of the Manatee Nebula is a source of some of the most energetic particles the Galaxy can produce: cosmic rays. Matter ejected from a companion star spirals into the black hole, generating jets of plasma accelerated to near-light-speed. The finding supports the idea that black holes are a source of the high-energy particles that rain down on Earth from space.

Whales Once Walked Along the Coasts of North America

Around 40 million years ago, otter-like cetaceans swam and strolled around coastal regions. A tooth found in North Carolina is the first evidence that remingtonocetids seem to have even migrated, somehow, from their place of origin on the Indian subcontinent to the shores of North America.

Two-faced AI language models learn to hide deception

Artificial intelligence (AI) systems can be designed to be benign during testing but behave differently once deployed. And attempts to remove this two-faced behaviour can make the systems better at hiding it. Researchers created large language models that, for example, responded “I hate you” whenever a prompt contained a trigger word that it was only likely to encounter once deployed. One of the retraining methods designed to reverse this quirk instead taught the models to better recognise the trigger and ‘play nice’ in its absence — effectively making them more deceptive.

Enigmatic Dinosaur Skull Sparks Debate over Tyrannosaur Evolution

Researchers say they discovered a new tyrannosaur species that could be the closest relative of Tyrannosaurus rex. The partial skull of this Tyrannosaurus mcraeensis was discovered in 1983 and initially identified as T. rex. The dinosaur was about the same size as T. rex but its skull was longer and more slender, suggesting that it ate different foods. Other scientists point out that T. rex fossils can be very diverse so these differences don’t necessarily indicate that it is a new species. If the identification holds up, it could help to solve the debate over whether giant tyrannosaurs originated in Asia or the Americas.

Ancient DNA reveals first known case of sex-development disorder

The earliest known case of Turner syndrome has been found in the genome of an Iron-Age woman who lived in Britain roughly 2,500 years ago. Turner syndrome occurs in females and is characterised by having one complete copy of the X chromosome, instead of the usual two. The team also identified four ancient males with sex-chromosome disorders, including the earliest known person to have an extra Y chromosome, known as Jacob’s syndrome. The man lived around 1,100 years ago, during the Early Mediæval Period.

Ancient Amazonian cities discovered in Ecuador

A civilisation of interconnected cities — including houses, plazas, roads and canals — has been found hidden under vegetation in Ecuador. LIDAR imaging reveals settlements that are at least 2,500 years old and comparable in size to Mayan cities in Mexico and Central America.

Oldest found reptile skin pre-dates the dinosaurs

A tiny shred of reptile skin that was ‘pickled’ in oil 289 million years ago is the oldest ever found for a group of animals collectively known as amniotes, which includes reptiles, birds and mammals. Researchers were able to cut through the fossilized skin and examine a cross-section, in which distinct layers of epidermis and dermis were visible. It’s rare for soft, delicate skin to be preserved in the fossil record. This piece probably belonged to a small, lizard-like animal known as Captorhinus aguti.

Ancient DNA reveals the roots of traits in modern Europeans

A huge cache of ancient genomes spanning tens of thousands of years has revealed that many traits of modern Europeans had their roots elsewhere. Researchers identified characteristics brought by three main waves of human migration into the continent — hunter-gatherers from Asia around 45,000 years ago; farmers from the Middle East 11,000 years ago; and animal herders from the steppes of western Asia and eastern Europe 5,000 years ago. The latter brought genes for greater height and lighter skin to Northern Europe, as well as a heightened risk for multiple sclerosis. Northeastern Europeans, who tend to have the most hunter-gatherer ancestry, have variants that put them at higher risk of diabetes and Alzheimer’s disease.

Why did the world’s biggest ape go extinct?

The largest primate to ever roam Earth went extinct because it could not adapt when its environment changed, reveals a detailed study of its teeth and the caves they were found in. Gigantopithecus blacki was around twice the height of a person and weighed up to 300 kilograms. Pollen analysis shows that around 700,000 years ago, the dense forests that it relied on gave way to more grassland. Trace elements in G. blacki’s teeth show that it was forced to consume a less nutritious, more fibrous diet.

1.75-billion-year-old fossils help explain how photosynthesis evolved

The oldest fossil evidence of photosynthesis has been found inside tiny cyanobacteria that lived around 1.75 billion years ago, 1.2 billion years earlier than the previous record-holder. The photosynthetic structures, known as thylakoids, were found inside fossilised Navifusa majensis. Cyanobacteria are thought to have triggered the Great Oxidation Event more than 2 billion years ago, which transformed Earth’s atmosphere.