Featured

Stanford researcher declares that the sixth mass extinction is here

There is no longer any doubt: We are entering a mass extinction that threatens humanity’s existence.

That is the bad news at the center of a new study by a group of scientists including Paul Ehrlich, the Bing Professor of Population Studies in biology and a senior fellow at the Stanford Woods Institute for the Environment. Ehrlich and his co-authors call for fast action to conserve threatened species, populations and habitat, but warn that the window of opportunity is rapidly closing.

“[The study] shows without any significant doubt that we are now entering the sixth great mass extinction event,” Ehrlich said.

Although most well known for his positions on human population, Ehrlich has done extensive work on extinctions going back to his 1981 book, Extinction: The Causes and Consequences of the Disappearance of Species. He has long tied his work on coevolution, on racial, gender and economic justice, and on nuclear winter with the issue of wildlife populations and species loss. Read more »

World

Sea level rise danger to larger number of people than previously estimated

More people live close to sea coast than earlier estimated, assess researchers in a new study. These people are the most vulnerable to the rise of the sea level as well as to the increased number of floods and intensified storms. By using recent increased resolution datasets, Aalto University researchers estimate that 1.9 billion inhabitants, or 28% of the world’s total population, live closer than 100 km from the coast in areas less than 100 meters above the present sea level. Read more »

Health

Mindfulness meditation provides opioid-free pain relief

Everyone knows that stubbing your toe hurts. What makes it stop hurting is the body’s main pain-blocking process – the natural production of opioids.

Cognitive-based approaches found to reduce pain, such as hypnosis, acupuncture, distraction and even the placebo response, have been shown to work through this system. But does meditation also use opioids to reduce pain?

In a study published in the current issue of the Journal of Neuroscience, a team led by Fadel Zeidan, Ph.D., assistant professor of neurobiology and anatomy at Wake Forest Baptist Medical Center, reports that mindfulness meditation does not employ the endogenous opioid system to reduce pain.

“Our finding was surprising and could be important for the millions of chronic pain sufferers who are seeking a fast-acting, non-opiate-based therapy to alleviate their pain,” Zeidan said.

The Institute of Medicine estimates that approximately 100 million Americans suffer from chronic pain at a cost of more than $600 billion annually for treatment. And due to the increase in the number of people addicted to opiate drugs, from prescription medications to heroin, the Centers for Disease Control has labeled the problem an epidemic.

To determine if meditation uses the body’s opioids to reduce pain, the Wake Forest Baptist researchers injected study participants with either a drug called naloxone, which blocks the pain-reducing effects of opioids, or a saline placebo.

In this randomized, double-blinded study, 78 healthy, pain-free volunteers were divided into four groups for the four-day (20 minutes per day) trial. The groups consisted of: meditation plus naloxone; non-meditation control plus naloxone; meditation plus saline placebo; or non-meditation control plus saline placebo.

Pain was induced by using a thermal probe to heat a small area of the participants’ skin to 49 degrees Centigrade (120.2 degrees Fahrenheit), a level of heat most people find very painful. Study participants rated their pain using a sliding scale.

Zeidan found that the participants’ pain ratings were reduced by 24 percent from the baseline measurement in the meditation group that received the naloxone. This is important because it showed that even when the body’s opioid receptors were chemically blocked, meditation still was able to significantly reduce pain by using a different pathway, he said. Pain ratings also were reduced by 21 percent in the meditation group that received the placebo-saline injection.

By comparison, the non-meditation control groups reported increases in pain regardless of whether they got the naloxone or placebo-saline injection.

“Our team has demonstrated across four separate studies that meditation, after a short training period, can reduce experimentally induced pain,” Zeidan said. “And now this study shows that meditation doesn’t work through the body’s opioid system.

“This study adds to the growing body of evidence that something unique is happening with how meditation reduces pain. These findings are especially significant to those who have built up a tolerance to opiate-based drugs and are looking for a non-addictive way to reduce their pain.”

The next step for Zeidan’s team is to determine if and how mindfulness meditation can affect a spectrum of chronic pain conditions.

“At the very least, we believe that meditation could be used in conjunction with other traditional drug therapies to enhance pain relief without it producing the addictive side effects and other consequences that may arise from opiate drugs,” he said.

US News

Clues from the animal kingdom on what makes a leader?

As the American media continues to buzz over who is more or less likely to secure the Republican and Democratic nominations for U.S. President, researchers in the journal Trends in Ecology & Evolution review some interesting perspectives on the nature of leadership. The experts from a wide range of disciplines examined patterns of leadership in a set of small-scale mammalian societies, including humans and other social mammals such as elephants and meerkats.

“While previous work has typically started with the premise that leadership is somehow intrinsically different or more complex in humans than in other mammals, we started without a perceived notion about whether this should be the case,” said Jennifer Smith of Mills College in Oakland, California. “By approaching this problem with an open mind and by developing comparable measures to compare vastly different societies, we revealed more similarities than previously appreciated between leadership in humans and non-humans.”

Chimpanzees travel together, capuchins cooperate in fights, and spotted hyenas cooperate in hunting, but the common ways that leaders promote those collective actions has remained mysterious, Smith and her colleagues say. It wasn’t clear just how much human leaders living in small-scale societies have in common with those in other mammalian societies either.

To consider this issue, a group of biologists, anthropologists, mathematicians, and psychologists gathered at the National Institute for Mathematical and Biological Synthesis. These experts reviewed the evidence for leadership in four domains–movement, food acquisition, within-group conflict mediation, and between-group interactions–to categorize patterns of leadership in five dimensions: distribution across individuals, emergence (achieved versus inherited), power, relative payoff to leadership, and generality across domains.

Despite what those ongoing presidential primaries might lead one to think, the analysis by the scientific experts finds that leadership is generally achieved as individuals gain experience, in both humans and non-humans. There are notable exceptions to this rule: leadership is inherited rather than gained through experience among spotted hyenas and the Nootka, a Native Canadian tribe on the northwest coast of North America.

In comparison to other mammal species, human leaders aren’t so powerful after all. Leadership amongst other mammalian species tends to be more concentrated, with leaders that wield more power over the group.

Smith says the similarities probably reflect shared cognitive mechanisms governing dominance and subordination, alliance formation, and decision-making–humans are mammals after all. The differences may be explained in part by humans’ tendency to take on more specialized roles within society.

“Even in the least complex human societies, the scale of collective action is greater and presumably more critical for survival and reproduction than in most other mammalian societies,” Smith said.

The researchers now plan to further quantify the various dimensions identified in the new work. There’s still plenty more to learn. “As ambitious as our task was, we have only just scraped the surface in characterizing leadership across mammalian societies and some of the most exciting aspects of the project are still yet to come as biologists and anthropologists implement our novel scheme for additional taxa and societies,” Smith said.