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It was around 1.6 billion years ago that a community of small, bright red, plantlike life-forms, flitting around in a shallow pool of prehistoric water, were etched into stone until the end of time. Or at least until a team of Swedish researchers chipped their fossilized remnants out of a sedimentary rock formation in central India. Research published this week in PLoS Biology suggests this collection of ancient, newly analyzed fossils—unearthed a few years back—are in all likelihood red algae....

Most people make good decisions most of the time. But when drug addiction, disease or brain injury enters the picture, rational thinking can go awry. What if the damaged brain just needed a little reminder of how it feels to choose wisely? Enter the MIMO neural prosthesis, an array of electrodes implanted in the brain that make contact with eight neuron circuits in the prefrontal cor-tex, the brain’s command center for decision making....

California has officially become the first U.S. state to require new homes to have rooftop solar panels, a major milestone in the Golden State’s hugely ambitious goal to shift all energy usage to 100 percent zero-carbon sources by 2045. But some economists doubt the rooftop rule will prove the most cost-effective way to cut greenhouse gas emissions for California—or other states seeking to address the human impact on climate change. The requirement is part of new building energy-efficiency standards the California Energy Commission (CEC) passed earlier this year....

Editor’s note: This story is part of a series of online exclusives about natural phenomena and human endeavors we’d like to see come to an end. They are connected with the September 2010 special issue of Scientific American called “The End”. Poliomyelitis—a viral disease that wreaks havoc on motor neurons, often paralyzing sufferers for life—was supposed to be banished from the planet a long time ago. When Jonas Salk unveiled his famed vaccine to the world in 1955, and Albert Sabin introduced an oral version shortly thereafter, inoculations began in earnest in many parts of the world, drastically lowering incidence numbers....

Could men and women rely on smell to find potential mates? Birds do, bees do—and now scientists have some reason to think that humans do, too. Growing evidence suggests that bodily odors carry chemical signals that affect moods and menstrual cycles, but isolating the specific compounds that elicit these effects, called pheromones, has proved difficult. Wen Zhou, a psychologist and olfaction researcher at the Chinese Academy of sciences, and her colleagues looked at two compounds found in bodily fluids that, according to earlier studies, are good candidates for human pheromones: androstadienone, associated with men, and estratetraenol, from women....

What is human uniqueness, and how did it contribute to what we could now call behavioral modernity? How did it develop? And what implications does it have for understanding our present and future? This past February the Origins Project that I direct at Arizona State University helped to convene an interesting meeting of paleontologists, anthropologists, primatologists, evolutionary biologists, geneticists, archaeologists and psychologists to attempt to address such questions, among others. I began the meeting by pointing out that when some people heard about its subject, they had asked me what was so unique about humans?...

By Madeline Chambers BERLIN (Reuters) - For all Angela Merkel’s headline-grabbing “green revolution”, Germany’s image as a world leader on environmental policies is in danger of falling under the shadow of the smoke stack and a cloud of exhaust fumes. Increasing dependence on brown coal has raised doubts about whether Berlin will hit its medium-term CO2 emission goals. And though EU regulations have helped bring down vehicle emissions, critics denounce the political reluctance to confront Germans’ passion for big, fast cars....

It has been a while since I wrote the episode called 6 Reasons Recovery is Essential to Your Exercise Routine and even longer since I did the podcast called The Perfect Workout Recovery Day, but I stand by my claim that it is the alternation between stress and rest that moves us to a higher and higher level of fitness. I also still believe that the higher the training intensity and effort, the greater the need for planned recovery....

Plants do not have to be green. To be sure, the vast majority of vascular plants on Earth are green because during photosynthesis (the conversion of photons of light into stored chemical energy) they absorb more of the red and blue wavelength light emitted by the sun. But in the murky depths of Earth’s waters lurk photosynthetic bacteria that appear purple to the human eye, employing light in the infrared spectrum to store energy; more archaic plants—such as lichens and moss—utilize more of the blue spectrum in visible light....

Modern high-yield farming lowered the amount of greenhouse gases pumped into the Earth’s atmosphere toward the end of the 20th Century by a massive amount, according to a surprising study from researchers at Stanford University. Technological advances in agriculture helped reduce greenhouse gas output by reducing the need to convert forests to farmland, the study said. Such conversion involves burning of trees and other naturally occurring carbon repositories, which increases emissions of carbon, methane and nitrous oxide....

Centuries of silence cannot keep ancient Egyptian mummies from sharing their secrets with scientists. From archaeologists determining cultural practices to chemists studying embalming, mummies have revealed libraries of information. Now such mummies are also yielding evidence about the diseases of the past by giving up the facts encoded in their preserved DNA, and new research may have pinned down the ancient homeland of a modern scourge. Leishmaniasis–a disease caused by microscopic parasites, like malaria, and transmitted by sand flies–results in painful skin sores and in its most vicious form causes at least 500,000 deaths worldwide every year....

CLIMATEWIRE | Right now, 12 wildfires are burning through nearly 280,000 acres in five states. Many more will burn in the months ahead, thanks to a changing climate that is resulting in widespread dryness across the U.S. Already, the country has seen hundreds of thousands more acres burn than usual for this time of year. Between Jan. 1 and May 4, wildfires had burned over 1.1 million acres. Over the last 10 years on average, those four months see about 707,000 acres burned, according to the National Interagency Fire Center (NIFC)....

This month, the U.N. Convention on Biological Diversity released a report updating the impacts of ocean acidification on marine life. This time, it put estimated costs on the predicted damage, hoping to make governments aware of the potential size of the various threats. While many of the effects of growing acidification remain invisible, by the end of this century, things will have changed drastically, the report found. One estimate looking only at lost ecosystem protections, such as that provided by tropical reefs, cited an economic value of $1 trillion annually....

Under a microscope, a pathologist searching through the damaged nerve cells in a brain tissue sample from a patient who has died of Alzheimer’s disease can make out strange clumps of material. They consist of proteins that clearly do not belong there. Where did they come from, and why are there so many of them? And most important, what do they have to do with this devastating and incurable disorder? The search for answers has turned up a startling discovery: the clumped proteins in Alzheimer’s and other major neurodegenerative diseases behave very much like prions, the toxic proteins that destroy the brain in mad cow disease....

It may seem extraordinary that one person’s life, and, as a consequence, so many other peoples’ lives, can be so radically reshaped by a moment’s irritation. But, with Paul Crutzen, one of the greatest scientists of his time—of all time—who passed away on the 28th of January after long illness, the extraordinary had come to be habitual. Already famous for revealing the likely outcome of a nuclear winter, and a Nobel laureate for his part in deciphering the mechanisms of atmospheric ozone loss, his sudden realization that humanity had very recently stumbled into a new geological epoch of its own making, the Anthropocene, created reverberations that continue to shake not only the world of science but that of all of scholarship, now spilling into political and economic discourse worldwide....

Mosquitoes have remarkably refined powers of smell. The insects that spread malaria across sub-­Sa­har­an Africa come exquisitely equipped to find human blood. They home in on the scent of human breath and sweat and swiftly insert their needlelike mouthparts into the target’s skin. As they dine, their saliva transmits the malaria parasite into the wound. With a simple bite, they can ultimately take a life. Other mosquitoes prefer different species—say, cattle or birds....

Key concepts Geometry Mathematics Shapes Dimensions Volume Introduction Has an adult ever caught you munching on candy and asked, “How much candy have you eaten?” Instead of saying, “I don’t know,” and possibly receiving a scolding, wouldn’t you rather respond, “I ate precisely 10.7 cubic centimeters of candy”? In this activity, you will investigate which mathematical formula is most accurate for estimating the volume of an M&M. Figure this out and the next time you are discovered while snacking on sweets, you might make a better impression....

With age and enough experience, we all become connoisseurs of a sort. After years of hearing a favorite song, you might notice a subtle effect that’s lost on greener ears. Perhaps you’re a keen judge of character after a long stint working in sales. Or maybe you’re one of the supremely practiced few who tastes his money’s worth in a wine. Whatever your hard-learned skill is, your ability to hear, see, feel, or taste with more nuance than a less practiced friend is written in your brain....

The official U.S. death toll from COVID has surpassed 600,000, but the true number is likely much higher. In a preprint study, global health professor Andrew C. Stokes of Boston University and his colleagues found that in 2020 in U.S. counties with significant excess deaths (deaths beyond the expected number), only 82 percent of them on average were attributed to COVID.* Some of the biggest gaps were in rural counties, particularly in the South and West....

By Ewen Callaway of Nature magazineThe Vatican has abruptly cancelled a controversial stem-cell conference that was set to be attended by the Pope next month.The Third International Congress on Responsible Stem Cell Research, scheduled for 25-28 April, was to focus on clinical applications of adult and reprogrammed stem cells. But a number of the invited speakers, including Alan Trounson, president of the California Institute for Regenerative Medicine in San Francisco, and keynote speaker George Daley, a stem-cell scientist at Children’s Hospital Boston in Massachusetts, are involved in research using human embryonic stem cells, which the Catholic Church considers unethical....