Your brain could be controlling how sick you get

Hello Nature readers,
Today we discover evidence that Homo sapiens used bows and arrows in Europe as early as the Middle Palaeolithic period. Plus, we learn that our brains could be controlling how sick we get, and hear how the global scientific community can support Ukraine after a year of war.

Surprise appearance of arrows in Europe

The first Homo sapiens to arrive in Europe might have hunted with bows and arrows, around 10,000 years earlier than was thought. In a 54,000-year-old-cave in southern France, alongside a H. sapiens tooth and tools, researchers found hundreds of stone points resembling arrowheads — the smallest of which were so tiny that they would have had enough force to kill an animal only if they were shot with a bow. The technology could have been unique to humans: Neanderthals might have inhabited the area at the same time, but there is no evidence that they also took up archery.

New evidence that Neruda was poisoned

Influential Chilean poet Pablo Neruda might have had the deadly toxin-forming bacterium Clostridium botulinum in his system when he died, according to a court-ordered investigation. The Nobel-prizewinning writer, senator and diplomat has long been suspected of having been murdered by the regime of dictator Augusto Pinochet, soon after the general overthrew the socialist government that Neruda supported in 1973. Remnants of lethal bacterial DNA inside Neruda’s teeth showed similar degradation patterns to Neruda’s DNA, suggesting their presence at the time of his death. But the evidence doesn’t prove that Neruda was poisoned, says molecular geneticist Hendrik Poinar, who helped with the investigation. It’s neither a “closed door” nor a “smoking gun”, he says.

Big step for Google’s quantum computer

Researchers have demonstrated for the first time that they can reduce calculation error rates by using more qubits (the quantum counterparts to the classical bit). Usually, the more qubits there are, the more likely it becomes that they are affected by two errors at the same time. The error-correction procedure using 49 qubits was able to recover from 2 simultaneous errors and with slightly better performance than a 17-qubit version. It’s the second of Google’s six milestones on the road to commercial quantum computers, after performing a calculation that would have taken thousands of years on an ordinary computer.

The world must ban AI weapons now

Robots that kill without human supervision aren’t science fiction any more, writes computer scientist Stuart Russell. Russia is already using semi-autonomous cruise missiles against Ukraine. And in 2020, the Libyan interim government used explosive-laden drones to hunt down retreating forces autonomously. Worse might be to come: one person could launch almost unlimited swarms of cheap microdrones — ‘slaughterbots’ — to wipe out political opponents or entire populations. Governments and organizations must put aside flimsy excuses and ban artificial-intelligence weapons now to prevent a “bleak future of robotic threats”, he argues.

How your brain controls how sick you get

Scientists are starting to decipher the biological mechanisms behind a phenomenon that many clinicians are aware of: mental states can have a profound impact on how ill we get — and how well we recover. “Most people probably assume that when you feel sick, it’s because the bacteria or viruses are messing up your body,” says neuroscientist Catherine Dulac. But her team showed that activating a brain structure called the hypothalamus triggered fever and appetite loss, even in the absence of a pathogen. Brain-stimulation treatments for autoimmune diseases and cancer are already nearing clinical trials, although exactly how the brain controls the body’s immune responses is still a mystery.