Scientific American - Biology

What Happens in the Amygdala... Damage to Brain's Decision-Making Area May Encourage Dicey Gambles

Tue, 09 Feb 2010 10:00:00 EST

Imagine you've lost your job. You have some money saved, and a chance to double it with a gamble. But if you lose the bet, you'll forfeit everything. What would you do? [More]

Python Predation: Big snakes poised to change U.S. ecosystems

Tue, 09 Feb 2010 08:00:00 EST

Brought to the U.S. as pets, Burmese pythons have made headlines with their uncontrolled spread in the Florida Everglades and willingness to challenge alligators for the position of top predator. A report released by the U.S. Geological Survey last fall delivered more bad news: two other constrictor species, also former pets, are thriving in the area, and six others could pose similar threats. Researchers fear that reproductive populations could spread and eat native animals into extinction.

The new interlopers--northern and southern African pythons, reticulated pythons, boa constrictors and four species of anacondas--have “ecological similarities,” explains Robert Reed, a USGS biologist and one of the authors of the report. “They are large invasive predators that native birds and mammals aren’t adapted to, and they are highly fecund, capable of producing up to 100 hatchlings in one nest.” They’re also big; some grow up to 20 feet and 200 pounds. They seize prey with their teeth and then wrap around the prey’s body, squeezing it to death.

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Welcome to Atlantis and the quest for nitrogen

Mon, 08 Feb 2010 16:01:00 EST

Editor's Note: Journalist and crew member Kathryn Eident and scientist Jeremy Jacquot are traveling on board the RV Atlantis on a monthlong voyage to sample and study nitrogen fixation in the eastern tropical Pacific Ocean, among other research projects. This is the first blog post detailing this ongoing voyage of discovery for Scientific American.com.

20 00.0457S x 084'59.9745W [More]

City Dwellers Drive Deforestation in 21st Century

Mon, 08 Feb 2010 15:01:00 EST

Globally, roughly 13 million hectares of forest fall to the blade or fire each year. Such deforestation has long been driven by farmers eking out a slash-and-burn living or loggers using new roads to cut inroads into pristine forest. But now new data appears to show that, at least for the first five years of the 21st century, big block clearings that reflect industrial deforestation have come to dominate, rather than smaller-scale efforts that leave behind long, narrow swaths of cleared land. [More]

Third-hand smoke contains carcinogens too, study says

Mon, 08 Feb 2010 15:01:00 EST

Anyone walking into a smoker's abode can tell you that the traces of tobacco use don't vanish when a cigarette or cigar is extinguished. But just what happens to this "third-hand" smoke once the air has cleared--and can it still be harmful? [More]

Life at the Bottom: The Prolific Afterlife of Whales (preview)

Mon, 08 Feb 2010 08:00:00 EST

On a routine expedition in 1987, oceanographers in the submersible Alvin were mapping the typically barren, nutrient-poor seafloor in the Santa Catalina Basin, off the shore of southern California. On the final dive of the trip, the scanning sonar detected a large object on the seafloor. Piercing through the abyssal darkness down at 1,240 meters, Alvin ’s headlights revealed a 20-meter-long whale skeleton partly buried in sediment. On reviewing the dive videotapes, expedition leader Craig Smith and his team saw that the skeleton was probably either a blue or a fin whale. The creature appeared to have been dead for years, but the bones and their surroundings teemed with life--wriggling worms, centimeter-size clams, little snails and limpets, and patches of white microbial mats. The skeleton was a thriving oasis in a vast, desertlike expanse.

Almost a year later Smith, an oceanographer at the University of Hawaii at Manoa, returned for a proper study of the skeleton site. His team described several species previously unknown to science, plus some that had been observed only in unusual environments, such as at deep-sea hydrothermal vents.

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Street Smarts: The BioBus Brings a Rolling Science Lab to Resource-Strapped Schools

Sat, 06 Feb 2010 10:00:00 EST

It's halfway through first period, and 10th-grade students at Frances Perkins Academy in Brooklyn are in science class--not in school, but on a specially outfitted bus parked outside. [More]

Moving forward with electronic health records

Fri, 05 Feb 2010 19:00:00 EST

NEW YORK--Almost a year since President Obama signed the American Recovery and Reinvestment Act (ARRA), which earmarked some $19 billion to get electronic health records off the ground, most of the country's medical and research institutions are still primarily pushing paper. [More]

How Toads Conquered the World [Slide Show]

Fri, 05 Feb 2010 16:01:00 EST

Cane toads are seemingly innocuous enough. First imported to Australia to control a beetle pest of sugarcane fields, they are now frog-marching their way across the island continent , wreaking havoc on in situ flora and fauna. The key to their domination has been protection from would-be predators and an ability to breed fast. But how were cane toads gifted with those traits in the first place? [More]

Defusing the Methane Greenhouse Time Bomb

Fri, 05 Feb 2010 10:00:00 EST

Methane trapped in Arctic ice (and elsewhere) could be rapidly released into the atmosphere as a result of global warming in a possible doomsday scenario for climate change, some scientists worry. After all, methane is 72 times more powerful as a greenhouse gas than carbon dioxide over a 20-year timescale. But research announced at the annual meeting of the American Geophysical Union this December suggests that marine microbes could at least partially defeat the methane "time bomb" sitting at the bottom of the world's oceans.

The conventional wisdom for decades has been that methane emanating from the seafloor could be consumed by a special class of bacteria called methanotrophs. It has long been known, for instance, that these organisms at the bottom of the Black Sea consume methane produced in its deep oxygen-free waters.

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Genetic Doping Next Athletic Cheat

Fri, 05 Feb 2010 09:42:08 EST

The Vancouver Olympics begin February 12th. And scientists are on high alert. Not just for well-known ways to gain an advantage, like steroids or blood doping. The researchers are also worried about what’s called genetic doping. It’s the latest in elite athletic cheating.

Researchers writing in the journal Science point to a few different types of gene therapy that could get hijacked for athletics instead of medical uses, like the treatment of obesity, diabetes or muscle disease. For example, genes for insulin-like growth factor could enhance muscle mass. And molecules that regulate the expression of genes may make athletes more energy efficient, or help create more slow-twitch muscle fibers.

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Prehistoric patterns: A dinosaur gets color from head to feathery tail

Thu, 04 Feb 2010 18:15:00 EST

Last week, researchers announced that they had been able to place, for the first time, original colors on a dinosaur --painting in striking stripes on Sinosauropteryx 's tail based on new evidence of pigment particles. Today, another team reports that they have decoded the colors of a different dino from head to tail. [More]

Athlete alert: Is genetic juicing set to replace steroids?

Thu, 04 Feb 2010 16:58:00 EST

When Olympic medals and multi-million-dollar contracts are at stake, athletes and coaches have been known to resort to drastic measures to strike gold. But as the steroid era evolves amidst increased testing and public hectoring, what other performance booster will enter the ring? [More]

Sperm cells' swimming secrets revealed

Thu, 04 Feb 2010 13:20:00 EST

The predictable swimming sperm featured in health class videos are rather uncharacteristic portraits of the life of these sex cells. [More]

Shining a Light on Plants' Quantum Secret to Boost Photosynthesis

Wed, 03 Feb 2010 14:31:00 EST

In less than one billionth of a second, plants from algae to redwoods transform 95 percent of the sunlight that falls on them--10 17 joules per second bathe the planet--into energy stored chemically as carbohydrates. The quantum key to doing that lies in a phenomenon known to physicists as quantum coherence, according to new research published in Nature on February 4. ( Scientific American is part of Nature Publishing Group.) [More]

Gunfight Tip: Faster to Draw Second

Wed, 03 Feb 2010 12:41:08 EST

(Gunshot.) Shhhh, just lie still, son, don’t try to talk. I know what you’re wondering. You come into town with the fastest draw in the West and I let you draw first and still you’re still the one lying here a bullet in ya. Well, if only you’d studied some neuroscience you’d know that being the fastest ain’t necessarily gonna help you, son. Why, a study just come out in the Proceedings of the Royal Society . That’s a Brit journal, don’t worry about it. Showed that I can go 10 percent faster reactin’ to you drawing your gun than if I just tried to draw my own gun first. Has to do with the way the nervous system’s set up. And that 10 percent more, why it more than made up for your puny advantage. They say the great physicist Neils Bohr wondered why the ones who drew second always seemed to win in Western movies. Well, now we know. Now gimme back my issue of Scientific American what you stole, you magazine rustler.

--Steve Mirsky

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Cold Comfort: Young Women with Cancer Can Freeze an Ovary to Keep Kids in the Picture

Wed, 03 Feb 2010 10:15:00 EST

As chemotherapy and radiation treatments improve, children with cancer are living longer. The average five-year survival rate for a range of childhood cancers increased from 58 percent to 81 percent between 1975 and 2005, according to statistics from the National Cancer Institute . But although many of these children now survive cancer-free into their reproductive years, their fertility might not. In young women and girls, direct radiation and chemotherapy drugs can stop egg production by the ovaries--meaning that along with the tumor, hopes for pregnancy are often eradicated. [More]

Low serotonin levels may prompt mysterious sudden infant death syndrome

Tue, 02 Feb 2010 16:01:00 EST

The most common cause of death of U.S. infants before their first birthday is the nebulous complication known as sudden infant death syndrome (or SIDS), according to the Mayo Clinic. The underlying causes of this condition , in which no immediate cause of death is revealed in an autopsy, remain unknown, vexing scientists and parents alike. [More]

Microsoft's Hands-Free Answer to the Nintendo Wii

Tue, 02 Feb 2010 08:00:00 EST

Editor's note: The online version of this story was posted on January 7.

When Nintendo’s Wii game console debuted in November 2006, its motion-sensing handheld “Wiimotes” got players off the couch and onto their feet. Now Microsoft hopes to outdo its competitor by eliminating the controller altogether: this past January it revealed details of Project Natal, which will give Xbox 360 users the ability to manipulate on-screen characters via natural body movement. The machine-learning technology will enable players to kick a digital soccer ball or swat a handball simply by mimicking the motion in their living room.

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Bonobo Chimps Stay Childlike

Tue, 02 Feb 2010 00:03:08 EST

When your kids misbehave, maybe you tell them to stop acting like a bunch of chimps. Well, that would be an insult to the familiar common chimp, Pan troglodytes , which actually grows up pretty fast. Now bonobos, the other chimp species, or Pan paniscus , enjoy horsing around well into adulthood. And a study in the journal Current Biology suggests that their laid-back development keeps bonobos forever young. [More]