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Every winter and spring, tens of thousands of endangered olive ridley sea turtles clamber onto the shores of Gahirmatha Marine Sanctuary, along India’s northeastern coast, to lay eggs in one of the world’s most spectacular phenomena—the arribada, or mass nesting, which occurs only in India, Costa Rica and Mexico. This past season, however, the arribada did not happen at Gahirmatha. Although turtles have occasionally failed to mass-nest in previous years, conservationists fear this time the cause is dredging for a new seaport....

Millions of men bear the genetic legacy of Genghis Khan, the famously fertile Mongolian ruler who died in 1227. Researchers have now recognized ten other men whose fecundity has left a lasting impression on present-day populations. The team’s study points to sociopolitical factors that foster such lineages, but the identities of the men who left their genetic stamp remains unknown. The case for Genghis Khan’s genetic legacy is strong, if circumstantial....

How long will global uranium deposits fuel the world’s nuclear reactors at present consumption rates? Steve Fetter, dean of the University of Maryland’s School of Public Policy, supplies an answer: If the Nuclear Energy Agency (NEA) has accurately estimated the planet’s economically accessible uranium resources, reactors could run more than 200 years at current rates of consumption. Most of the 2.8 trillion kilowatt-hours of electricity generated worldwide from nuclear power every year is produced in light-water reactors (LWRs) using low-enriched uranium (LEU) fuel....

In Arizona, it allowed state officials to get daily reports on overdoses. In Alaska, it allowed officials to expand naloxone use. In Massachusetts, it led to new prescription monitoring guidelines and even a controversial ban on a specific painkiller. But at the national level, Health and Human Services Secretary Tom Price said Tuesday the Trump administration did not yet think it was necessary to declare a state of emergency regarding the opioid crisis....

Just how significant a role did hunting play in human evolution? It’s a question researchers have grappled with for decades. In an article in the April Scientific American I explore some of the latest findings that bear on how our ancestors became such successful predators and how their shift toward meat-eating itself fostered change in our lineage. For more on meat-eating, hunting and the evolution of our genus, Homo, check out the links below....

The wasps and bees buzzing around your garden might seem like simple-minded creatures. They build nests, forage for nectar, raise their young and then die, their lives typically playing out over the course of a single year or less. Some of these species rival humans and other primates in at least one intellectual skill, however: they recognize the individual faces of their peers. More specifically, members of a species of paper wasp can perceive and memorize one another’s unique facial markings and are able to use this information to distinguish individuals during subsequent interactions, much as humans navigate their social environment by learning and remembering the faces of family, friends and colleagues....

It’s May, which means “proxy season” in the corporate world. This is the time of year when publicly traded companies hold their shareholder meetings, and investors can vote on resolutions to change corporate policies. The votes can have plenty of clout because huge private investment firms such as BlackRock and Vanguard weigh in, as do major public shareholders such as California’s and New York’s employee retirement funds with billions of dollars in stock under their control....

A salty ocean is lurking beneath the surface of Jupiter’s largest moon, Ganymede, scientists using the Hubble Space Telescope have found. The ocean on Ganymede—which is buried under a thick crust of ice—could actually harbor more water than all of Earth’s surface water combined, according to NASA officials. Scientists think the ocean is about 60 miles (100 kilometers) thick, 10 times the depth of Earth’s oceans, NASA added. The new Hubble Space Telescope finding could also help scientists learn more about the plethora of potentially watery worlds that exist in the solar system and beyond....

The earliest stages of dinosaur evolution remain buried under eons of rock, but the discovery of a new primitive carnivore fossil in the U.S. Southwest promises to dispel some of the debate about how these beasts spread across the globe—and about the origins of the group that eventually led to modern birds. “It gives us new information about early evolution of dinosaurs,” Sterling Nesbitt, a postdoctoral researcher at the University of Texas at Austin’s Jackson School of Geosciences, said about the discovery during a Web cast with reporters on Wednesday....

When the levees collapsed in New Orleans, the faith of Americans in their government’s ability to protect them against natural disasters crumbled as well. Michael Chertoff, the secretary of homeland security who led the federal response, called Hurricane Katrina and the flood it spawned an “ultracatastrophe” that “exceeded the foresight of the planners.” But in truth the failure was not a lack of foresight. Federal, state and local authorities had a plan for how governments would respond if a hurricane were to hit New Orleans with 120-mile-per-hour winds, raise a storm surge that overwhelmed levees and water pumps, and strand thousands inside the flooded city....

From 1935 to 1975, just about everyone busted for drugs in the U.S. was sent to the United States Narcotic Farm outside Lexington, Ky. Equal parts federal prison, treatment center, research laboratory and farm, this controversial institution was designed not only to rehabilitate addicts, but to discover a cure for drug addiction. Now a new documentary, The Narcotic Farm, reveals the lost world of this institution, based on rare film footage, numerous documents, dozens of interviews of former staff, inmates and volunteer patients, and more than 2,000 photographs unearthed from archives across the country....

When you read hundreds of letters from readers every month, as I do, common patterns of argument emerge. I can’t answer every note individually, so in this column I’d like to at least respond to one type of assertion. That is the idea, whenever the letter writer doesn’t agree with an expert-informed point of view expressed in Scientific American, that science should not mention or touch on politically sensitive areas—that science is somehow apart from social concerns....

Picturing Science and Engineering by Felice C. Frankel. MIT Press, 2018 ($39.95). While on a fellowship at Harvard University, photographer Frankel audited a course by chemist George Whitesides. She was captivated by pictures from his laboratory—but knew she could do better. She continued to hone her skills and has spent her career making striking images that have been featured on many notable journal covers. This beautiful and engaging book is her latest practical guide to help other scientists use their creativity and basic lab tools (even the seemingly prosaic flatbed scanner) to create standout visualizations of their work and research subjects....

A young scientist with curly, reddish hair tucked beneath a knit cap stepped gingerly onto the three-day-old ice of a remote lake in northeastern Siberia. Coating the black depths like cellophane, the thin film held no promise to bear her weight, but a sudden dunk in the frigid water was a risk she had to take. Searching the lake by rickety rowboat all summer had failed, and any day winter’s first big snow would engulf the region, obscuring the lake’s surface until spring....

It’s a recurring story in American media: a black man is subject to excessive punishment by the police. Often, this is chalked up to malicious discrimination, pure and simple. But new research conducted by myself and a team of collaborators (Tobias Rothmund, Mathias Twardawski, Natasha Thalla, and Jay Van Bavel) raises the question of whether acts of disproportionate punishment are, at least in part, due to psychological factors ingrained in us all....

How many stages of life are there? According to Hindu teachings, human life unfolds in four stages: childhood, apprenticeship, adulthood and old age. William Shakespeare in As You Like It insisted on seven, beginning with infancy, when we are “mewling and puking,” and ending with old age, when we are “sans teeth, sans eyes, sans taste, sans everything.” It will come as no surprise that social scientists have expressed their own opinions on the matter, often arguing over the details and sometimes specifying different sets of stages for different abilities, such as cognitive development (Jean Piaget), moral reasoning (Lawrence Kohlberg) and psychosexual development (Sigmund Freud)....

A growing number of people are seeking alternatives to antidepressant medications, and new research suggests that acupuncture could be a promising option. One new study found the traditional Chinese practice to be as effective as antidepressants, and a different study found that acupuncture may help treat the medications’ side effects. In acupuncture, a practitioner inserts needles into the skin at points of the body thought to correspond with specific organs (right)....

Climate change is shifting weather extremes, increasing the frequency of drought and heat waves and the intensity of rainstorms – changes that will require the world’s governments to change how they cope with natural disasters, the Intergovernmental Panel on Climate Change (IPCC) said today. The report, written by more than 100 of the world’s top scientists, recommends taking steps now to increase the world’s ability to adapt and cope with climate extremes....

Editor’s Note (9/4/20): Drugmakers worldwide are working overtime to produce vaccines for COVID-19. If delays emerge, they may need to rely on costly biotech such as monoclonal antibodies. In this article, Scientific American details another approach making progress in Costa Rica, where inexpensive horse antibodies are being developed against the novel coronavirus. Development of the hundreds of vaccines and therapies for COVID-19 is by no means confined to metro areas surrounding San Francisco, Boston or Washington, D....

The collective random motion of tiny bacteria can be harnessed to turn much larger mechanical gears in a preestablished direction, a new study demonstrates. The research, set to be published online this week by the Proceedings of the National Academy of Sciences, presents a new spin on the concept of the so-called Brownian ratchet, in which arbitrary fluctuations generate directed motion to power tiny mechanical systems. The random and omnipresent movement of particles in a fluid, known as Brownian motion, presents on its face a tantalizing avenue to perpetual motion....