Tools shake up humanity’s story
Archaeologists have discovered a hoard of 2.4 million–year-old stone tools in Algeria, a find that could upend the long-held theory that humanity first emerged in East Africa. The 250 sharp-edged implements were stashed some 200 miles east of Algiers, alongside an array of fossilized animal bones with cut marks—possible evidence of prehistoric butchery. The artifacts resemble tools previously unearthed only in East Africa and predate other tools found in North Africa by at least 600,000 years. Scientists had believed that early humans, our ancient ancestors, stayed in East Africa for millions of years before eventually spreading across the continent. The new discovery throws up two possibilities: that primitive tool-using hominins from East Africa spread across the continent much faster than previously thought, or that early hominins were developing tools in different parts of Africa at the same time. “The evidence from Algeria shows that the cradle of humankind was not restricted to only East Africa,” study leader Mohamed Sahnouni, from Spain’s National Research Centre on Human Evolution, tells NewScientist.com. “The entire African continent was the cradle of humankind.”
double the size of all the life found in the world’s oceans. That’s the conclusion of 1,200 scientists who are nearing the end of a decade-long international project to examine the mysterious microbes that inhabit Earth’s subsurface, reports ScienceDaily .com. Researchers with the Deep Carbon Observatory gathered samples from hundreds of underground sites around the world—including diamond mines, 3-miledeep boreholes, and underwater mud volcanoes. They calculated that the subterranean ecosystem could contain up to 25 billion tons of carbon—hundreds of times more than is woven into all 7.5 billion humans. Some 70 percent of the microbes on Earth are thought to live in the subsurface, including many organisms that are unlike anything above ground. Some breathe uranium and expel the waste as crystals, while others live in deep-sea hydrothermal vents with temperatures of 250 degrees Fahrenheit.
“It’s probably reasonable to assume that the subsurface of other planets and their moons is habitable,” says Rick Colwell, a professor from Oregon State University, “especially since we’ve seen here on Earth that organisms can function far away from sunlight.”
program, had developed longer telomeres in their white blood cells, reports The New York Times. Telomeres are tiny caps on the ends of chromosomes that protect DNA from damage. These caps shrink as humans get older, eventually resulting in cell death and disease. But aerobic exercise appeared to lengthen the participants’ telomeres, dialing back the aging process. Scientists found no lengthening in the telomeres of participants who took up weight training. The message of the study, says lead author Christian Werner, is that aerobic exercise is good for people of any age. “It is not too late,” he says, “to keep your cells young.”