Archives: Science
Ancient DNA reveals diverse origins of Caribbean’s earliest inhabitants
The Caribbean, which today includes a diverse mix of human cultures, was one of the last places in the Americas occupied by people. Yet researchers don’t know precisely where these early migrants came from when they arrived somewhere between 8000 and 5000 years ago. Now, ancient DNA suggests the deep history of the Caribbean includes complex tales of migration and mingling, including how descendants of the first waves of inhabitants interacted with newcomers who arrived beginning 2800 years ago.
Insect wings evolved from legs, mayfly genome suggests
Along rivers and streams around the world, mayflies are a rite of spring. The mosquito-size insects lead double lives, with the young thriving in water and the adults emerging by the millions around June for just a few hours to mate and quickly die. There can be so many that they clog traffic, make roads slick, and even create a smelly mess.
Designer antibodies fight cancer by tethering immune cells to tumor cells
Amy Boland has gone through many ups and downs since she noticed lumps under her arms 12 years ago and learned she had cancer of the lymph system. For about 6 years, conventional chemotherapy helped shrink her lymphoma tumors, but they started to grow again. A succession of other cancer therapies, including a bone marrow transplant and a class of drugs called checkpoint inhibitors, either failed or only brought temporary relief. In one elaborate effort, physicians harvested her T cells, engineered those immune cells to kill her lymphoma, and infused them back into her body. The cancer vanished, but 2 years later bounced back. “Nothing was really working,” says oncologist Stephen Schuster of the University of Pennsylvania (UPenn).
Eye-catching advances in some AI fields are not real
Artificial intelligence (AI) just seems to get smarter and smarter. Each iPhone learns your face, voice, and habits better than the last, and the threats AI poses to privacy and jobs continue to grow. The surge reflects faster chips, more data, and better algorithms. But some of the improvement comes from tweaks rather than the core innovations their inventors claim—and some of the gains may not exist at all, says Davis Blalock, a computer science graduate student at the Massachusetts Institute of Technology (MIT). Blalock and his colleagues compared dozens of approaches to improving neural networks—software architectures that loosely mimic the brain. “Fifty papers in,” he says, “it became clear that it wasn’t obvious what the state of the art even was.”
Mysterious ancient rock art may have been made with beeswax
This 500-year-old rock art is among the rarest in the world. Found at a site called Yilbilinji near northern Australia’s Gulf of Carpentaria—and depicting a humanlike figure holding a boomerang (right), surrounded by more boomerangs—it’s a type of stenciling that involved creating miniature outlines of humans, tools, and other shapes. Similar, much older mini-stencils have been found elsewhere in Australia and around the world. Now, scientists think they know how ancient people made them.
Hungry bumble bees make plants flower early by cutting holes in their leaves
When bumble bee queens emerge from hibernation, they need to gather pollen and nectar to start their new colonies. If they wake up too soon, there may not be enough flowers in bloom. Now, researchers have discovered the bees have a way to order some fast food: They nibble holes in leaves, spurring plants to blossom weeks ahead of schedule. Many questions remain about the details of this strategy and how it evolved.
Cold War satellites inadvertently tracked species declines
When the Soviet Union launched Sputnik into orbit in 1957, the United States responded with its own spy satellites. The espionage program, known as Corona, sought to locate Soviet missile sites, but its Google Earth–like photography captured something unintended: snapshots of animals and their habitats frozen in time. Now, by comparing these images with modern data, scientists have found a way to track the decline of biodiversity in regions that lack historic records.
How Venus flytraps evolved their taste for meat
How does a plant develop a taste for flesh? In the play Little Shop of Horrors, all it takes is a drop of human blood. But in real life, it takes much more. Now, a study of three closely related carnivorous plants suggests dextrous genetic shuffling helped them evolve the ability to catch and digest protein-rich meals.
Can nuclear fallout make it rain?
Radioactive fallout is rarely a good thing. But new research suggests charged particles emitted from Cold War–era nuclear tests may have boosted rainfall thousands of kilometers away from the testing sites, by triggering electrical charges in the air that caused water droplets to coalesce.
New solar panels suck water from air to cool themselves down
Like humans, solar panels don’t work well when overheated. Now, researchers have found a way to make them “sweat”—allowing them to cool themselves and increase their power output.