New Scientist International Edition 9-Apr-22

Academy The science of your well-being Does being healthier actually make us happier? This course considers the way that the interactions of mind, body, diet and exercise affect our lives, for better or for worse. Leading experts will explain how we can change our habits and how food and exercise influence our physical and mental health, and debunk many myths about the well-being industry along the way. academy.newscientist.com Event Physics at the end of the universe The big bang theory tells the story of the beginning of the universe. But how does that story end? Join astrophysicist Katie Mack as she tells us about the ultimate fate of our cosmic home, and what the catastrophic destruction of all reality would look like to anyone still around to see it. Watch online at 6pm BST on 28…

IT WAS out in the desert of New Mexico that humanity first tested the atomic bomb, creating an explosion that left an indelible imprint on our planet. In the same area, just a few dozen kilometres south, scientists are now finding imprints of quite a different sort: human footprints from the Stone Age. These tracks don’t have anything like the historical significance of the first nuclear test – and that is precisely why they are so important. Archaeology often focuses on the big picture: technological shifts, epic migrations, the fall of civilisations. By contrast, the stones and bones we dig up rarely provide a clear sense of what everyday life was like for ordinary people, especially when it comes to the earliest humans, of whom there is precious little archaeological evidence…

GREENHOUSE gas emissions must peak within three years to hold global warming to 1.5°C, according to the latest research from the Intergovernmental Panel on Climate Change (IPCC). In a report on how countries can tackle the climate crisis, published on 4 April, the IPCC warned that the window for staving off highly dangerous warming has shrunk drastically due to past failures to act. It found that the world can afford to emit just 500 gigatonnes of carbon dioxide from 2020 onwards for a 50 per cent chance of holding temperature rises to 1.5°C. Scenarios modelling how to meet that tight “carbon budget” require emissions to peak by 2025, before falling 43 per cent by 2030 on 2019 levels. That would require a gargantuan effort, given global emissions rose by a record 5.5…

THE message is very clear. In three instalments, the Intergovernmental Panel on Climate Change (IPCC) has told us that humans are “unequivocally” to blame for rising temperatures, we are outstripping our ability to adapt and, on 4 April, that we can fix this crisis. The fix requires us to ensure that global greenhouse gas emissions peak in three years and are cut by 43 per cent by 2030. Achieve that, and we have a 50 per cent chance of staying under 1.5°C of global warming, the threshold for when climate impacts become far more damaging. Yet, as the IPCC itself points out, without stronger policies from governments, global emissions are projected to keep rising beyond 2025. The current trajectory is for a planet that has warmed by a hellish 3.2°C. So…

THE genomes of more than 600 plants, animals and fungi that went extinct tens or even hundreds of millions of years ago, leaving no physical trace on Earth, have been partially reconstructed by rewinding the evolutionary history of their living descendants. This has given us the best pictures so far of the genomes of various distant ancestors of humans, from the ancestor of monkeys and apes all the way back to the ancestor of the first amphibians and of all vertebrates. Almost all that we know about past life comes from fossils. As important as they are, most fossil species aren’t the direct ancestors of the organisms alive today. For instance, almost all dinosaurs died out, with just one branch surviving in the form of birds. “It’s not easy to connect a…

Ancestral genomes could help efforts to resurrect species such as the woolly mammoth. Several groups hope to create animals that resemble extinct species by sequencing the DNA in preserved samples, then editing the genome of a close living relative to make it a good match for the extinct species. The problem with this approach, says Thomas Gilbert at the University of Copenhagen in Denmark, is that ancient DNA breaks into lots of little pieces. The only way to reassemble them is to use the genome of a living relative as a guide. But both the extinct and living species will have changed since splitting from their common ancestor, so the reassembled ancient genome will have some key parts missing. In a 2020 study, Gilbert and his colleagues showed that reconstructing the genome of…