Archivo: Science

If you picture early humans dining, you likely imagine them sitting down to a barbecue of mammoth, aurochs, and giant elk meat. But in the rainforests of Sri Lanka, where our ancestors ventured about 45,000 years ago, people hunted more modest fare, primarily monkeys and tree squirrels. Then they turned the bones of these animals into projectiles to hunt more of them. The practice continued for tens of thousands of years, making this the longest known record of humans hunting other primates, archaeologists report today.

In an attempt to prove that the Turin Shroud—a strip of linen that some people believe was used to wrap Jesus’s body after his crucifixion and carries the image of his face—is real, researchers have strapped human volunteers to a cross and drenched them in blood. Most mainstream scientists agree the shroud is a fake created in the 14th century,

Stonehenge may be the most famous example, but tens of thousands of other ancient sites featuring massive, curiously arranged rocks dot Europe. A new study suggests these megaliths weren’t created independently but instead can be traced back to a single hunter-gatherer culture that started nearly 7000 years ago in what is today the Brittany region of northwestern France. The findings also indicate societies at the time were better boaters than typically believed, spreading their culture by sea.

Of all the many ways the teeming ecosystem of microbes in a person’s gut and other tissues might affect health, its potential influences on the brain may be the most provocative. Now, a study of two large groups of Europeans has found several species of gut bacteria are missing in people with depression. The researchers can’t say whether the absence is a cause or an effect of the illness, but they showed that many gut bacteria could make substances that affect nerve cell function—and maybe mood.

From certain angles, the Flerov Laboratory of Nuclear Reactions here looks more like an auto repair shop than a legendary scientific institute. Scientists in dirty blue smocks walk around while an oil pump thumps out a techno beat. Tables are strewn with bolts and cleaning fluids, including a vodka bottle half full of ethanol. And spare parts are everywhere—bins, shelves, whole walls full of metal whatsits in all manner of disrepair.

Poor oral health is a risk factor for Alzheimer’s disease. What’s not clear is whether gum disease causes the disorder or is merely a result—many patients with dementia can’t take care of their teeth, for example. Now, a privately sponsored study has confirmed that the bacteria that cause gum disease are present in the brains of people with Alzheimer’s, not just in their mouths. The study also finds that in mice, the bacteria trigger brain changes typical of the disease.

A new study of the genes of more than 6000 people from five Latin American countries undercuts the simplistic racial assumptions often made from skin color.

The compound eyes of the common fruit fly are normally brick red. But in neurologist Tom Lloyd’s lab at Johns Hopkins University School of Medicine in Baltimore, Maryland, many of the fly eyes are pocked with white and black specks, a sign that neurons in each of their 800-odd eye units are shriveling away and dying.

A new Canadian radio telescope, not yet fully operational, has already detected more than a dozen of the mysteriously brief blasts from deep space known as fast radio bursts (FRBs). One is only the second known to flash repeatedly, researchers reported here today at the annual meeting of the American Astronomical Society. The early results from the Canadian Hydrogen Intensity Mapping Experiment (CHIME) suggest the scope is well on its way to adding hundreds or even thousands of FRBs to the 60 or so already known—hopefully revealing the source of these powerful millisecondslong pulses in the process.

The pinnacle of beauty to most people is a symmetrical face, one without any major left-right differences. But for blind Mexican cavefish (Astyanax mexicanus), asymmetry may be a lifesaver. That’s because their lopsided skulls may help them feel their way along dark cave walls—similar to a person navigating by touch in the dark. That behavior, presented here this week at the annual meeting of the Society for Integrative and Comparative Biology, suggests being a little “off” can have evolutionary benefits.