Humans have always been proud about inventing agriculture 10,000 years ago, and we've had to nurse our egos a bit after learning that ants, beetles and snails also cultivate crops. But now that a new study shows even the lowly amoeba has a green thumb, maybe we should be embarrassed we didn't start farming earlier. Researchers from Rice University have found that the soil-dwelling amoeba Dictyostelium discoideum (pictured) not only disperses seeds of its favorite bacteria, but also selectively harvests the crops. That makes it the tiniest farmer known to science, an adaptation that gives the simple organism "a serious advantage," says Rice evolutionary biologist Debra Brock, the study's lead author.
"In a situation where they find a food source they don't like and they're carrying the bacteria they'd like to eat, the farmers can grow it for themselves," Brock tells the New York Times. "And they harvest; they don't eat all of it, but they save some." Scientists have long thought such "slime mold" amoebae simply scavenge for food, and whenever bacteria show up in their petri dishes, researchers usually clean them out, considering them contaminants. But as Oxford biologist Kevin Foster explains to Wired, the Rice team suspected their amoeba "contamination" wasn't accidental. "The typical response to finding two species in a culture is, 'Ick, I don't want this!'" he says. "[Brock's team] had the insight to realize this was more than a simple contamination, that something else was going on here."
In fact, what was going on was farming: Brock's team found that certain strains of the amoeba didn't "lick the plate clean" of bacteria like others did, but instead saved some inside the colony. Members of this strain all share a genetic trait that apparently makes them farmers, and they survived better in some soils than their non-farming relatives. But we shouldn't feel threatened by these amazing amoebae — instead, Brock says, we should focus on how much we have in common. "As humans, we have very intimate relationships with microorganisms," she tells Wired. "[Slime molds] have amazing similarities to humans, with all kinds of developmental genes similar to ours, and even have immune systems. We can use them to attack basic questions about ourselves."
The situation in Brazil continues to decline following the country's worst flooding and mudslides in decades, with the death toll reaching 741 and the number of missing people possibly more than 300. The list of casualties is still rising rapidly as rescuers push into isolated areas, digging out more and more bodies from neighborhoods that were overwhelmed by mud and rain. The disaster was triggered by intense storms that dumped heavy rainfall onto southeast Brazil last week, and the ensuing floods have been powerful enough to transform the local geography, officials say. "Streams turned into wide, deep rivers. There is a huge geographical change; it's as if towns were completely reshaped," the president of a government public-works firm tells Reuters. "People in these mountainside areas aren't as secure as they used to think."
A lack of urban planning across much of Brazil has allowed the construction of many neighborhoods in areas with a high risk of flooding and mudslides, Reuters points out, and critics also say the government's disaster readiness and response protocols are inadequate. But much like the widespread floods that have devastated Australia, Sri Lanka and Pakistan in recent months, Brazil's flooding may be part of a broader problem: global warming. No single weather event can be directly traced to climatic changes, but these kinds of epic disasters are precisely what experts say we'll start seeing more often as the planet heats up.
That connection was highlighted further today by the U.N.'s World Meteorological Organization, which released a new report confirming that 2010 tied for the warmest year on record. Average global temperatures last year were 0.95 degrees Fahrenheit higher than the 1961-1990 average, backing up previous reports by NASA and NOAA that 2010 tied 1998 and 2005 as the warmest year since record-keeping began in 1880. And because that excess heat speeds up evaporation of the world's oceans, warming is widely expected to bring wilder weather — including the kinds of storms behind the recent spate of flooding disasters.
Having a fireplace in your home has long been seen as a sign of wealth, but that image may now be going up in smoke, the New York Times reports. Fireplaces have begun building up a social stigma in recent years almost as quickly as they build up ash and soot, as homeowners grow increasingly aware of their effect on personal and environmental health. "A wood-burning fire in the city is a ridiculous luxury — we would never have put it in ourselves," one NYC resident tells the Times. "In the city, it doesn't make sense to burn fires, because it's inefficient and it's polluting."
The fireplace is "joining the ranks of bottled water and big houses," writes the Times' Christina Lewis, signaling its owner's environmental ignorance as much as any kind of social prestige. That's because the smoke from a fireplace is no better than any other kind of smoke — it produces tiny particles that can, according to the Natural Resources Defense Council's Diane Bailey, "cause inflammation and illness, and can cross into the bloodstream, triggering heart attacks" and other health problems. "We now know from lots of studies that wood smoke is very, very irritating," says Dr. Norman Edelman of the American Lung Association. "It contains a lot of irritating gases and it also contains damaging particulate matter. It's probably not good for anybody, and it's especially bad for anybody who has a chronic respiratory problem."
This realization seems to be having an effect, with sales of wood-burning appliances falling from 800,000 in 1999 to 235,000 in 2009; the Brick Industry Association also reports that only 35,000 masonry fireplaces were installed in the U.S. in '09, compared with 80,000 four years earlier. Lewis points out this is at least partly due to the recession, but adds that a growing awareness of fireplaces' health risks can't be ruled out. While some municipalities are going as far as restricting wood-burning fireplaces, though, there are still ways to compromise, such as switching to an EPA-certified wood or pellet stove, or adding a metal insert to help a fireplace heat more efficiently. But as one resident of the chilly mountain town Boone, N.C., tells the Times, cutting back on the number of fires is the simplest strategy. "We're in the Appalachian Mountains, and I know what pollution does to us all," she says. "I very definitely limit fires. I'd have one every single winter night if I didn't have some guilt."
(Source: New York Times)
The entire planet could be running on 100 percent renewable energy by 2030, according to a new study published in the journal Energy Policy, if the political will could be mustered to actually try. The study's authors say they aimed to prove that enough renewable energy is available and could be harnessed to meet demand indefinitely within the next 20 years, even their work turns out to be just an academic exercise. While it's possible, reaching that goal wouldn't be easy — it would mean building 4 million 5-megawatt wind turbines, 1.7 billion 3-kilowatt rooftop solar power systems, and about 90,000 300-megawatt solar power plants.
But the fact that it is possible lends tantalizing new credibility to the renewable-power sector, which perennially struggles to compete with cheaper but nonrenewable fossil fuels such as coal, oil and natural gas. The study's authors left all such fossil fuels out of their calculations, concentrating only on wind, solar, waves and geothermal power sources. That's a big deal, since fossil fuels currently supply about 80 percent of the world's energy, and the researchers also excluded nuclear power — which supplies 6 percent of global energy — since it's nonrenewable, too. That left them with a substantial gap to fill, especially since they even left out biomass, which is technically renewable but is linked to concerns about pollution and land use.
They managed to fill that gap, but it would require a worldwide frenzy of building that's unlikely to happen overnight. Plus, switching to more battery-operated devices and vehicles would also increase demands on certain minerals and rare-earth elements, potentially creating new environmental problems in place of old ones. Yet those are surmountable setbacks, the researchers argue, that shouldn't overshadow the news that 100 percent renewable energy is technically — if not politically — possible.
Two teams reach the South Pole, an environmental R&B song drops, and more.
Want to receive the day's eco-news in your inbox? Click here to sign up for the Daily Briefing newsletter.
Photo (Dictyostelium discoideum): Scott Solomon/National Science Foundation
Photo (flood damage in Teresopolis, Brazil): ZUMA Press
Photo (wood-burning fireplace): Getty Images
Photo (wind-turbine blades): U.S. National Renewable Energy Laboratory