Next time you’re in the supermarket weighing
the glossy conventional fruit against the small, blotched organic alternative, consider this: organic fruits’ stunted size may be the signal of their nutritional prowess.
Various studies in recent years have shown that some organic fruits and vegetables have nutritional advantages over conventionally-grown produce. For instance, organic tomatoes contain more vitamins, and organic tomato juice has more phenolics, a class of molecules that promote the body’s own antioxidant response.
But it’s been unclear exactly how organic farming brings about these changes in fruit. Now a new study indicates that the secret is stress: While conventional fruits are coddled by synthetic fertilizers, organic plants have fewer minerals available to them—and they therefore produce fruit that’s higher in human-healthy compounds.
As global pollinator populations decline, the pressure is on for scientists to figure out what makes these buzzing insects tick. While bumblebees do not pollinate much of the food we humans eat, their fuzzy bodies move a lot of pollen for native plant species, which makes them an essential part of many an ecosystem. Tracking the nesting and eating habits of bumblebees has given scientists some surprising new clues about how to encourage pollination in an ever-urbanizing world.
“Integrated pest management” is a mouthful. But the farming method, involving growing multiple crops together and playing their strengths and weaknesses off each other, could be key to using fewer chemicals to grow more food. Though it’s been discussed for decades, a set of recent experiments reported in the journal PLOS ONE puts more weight behind it: using this style of farming with moderate use of fertilizers and pesticides, the study found, is just as productive as industrial agriculture while requiring fewer chemicals. Read More
Unlike pesticide-laden conventional food, organic produce is more natural, healthier, and better for you…right? Organic food does contain less synthetic pesticides. But the natural pesticides that replace them can also have harmful effects. For example, the organic pesticide copper sulfate is more toxic than some synthetic pesticides, and it can cause genetic mutations, cancer, liver disease, and anemia. No matter what you choose to eat, both conventional and organic produce can expose you to low levels of pesticides. Before you forswear all greens, however, bear in mind that low pesticide levels aren’t the worst thing in the world.
At her Science Sushi blog on Scientific American’s network, Christie Wilcox explains that a little bit of pesticide exposure can actually be good for you.
A pest-eating ladybug attacks an aphid.
As angry debates about genetic modification continue, GM crops are quietly going about their business—and producing some positive side effects. In China, with Bt cotton reducing the need for insecticides, pest-eating bugs have rebounded and brought natural pest control with them.
China’s genetically modified cotton is not new. Farmers used to spray their cotton with a protein, naturally produced by the Bacillus thuringiensis (Bt) bacteria, which is toxic to certain insects. As research into genetically modified crops advanced, scientists implanted the cotton itself with the Bt genes that code for production of the insect toxin, creating so-called “Bt cotton” and alleviating the need for the sprayed insecticide. Since China approved its use in 1997, Bt cotton has proved itself particularly effective against the cotton bollworm moth, reducing the costs and side effects of spraying pesticides, but it has had may also decrease the number of non-pest insects compared with organic fields.
With the advent of Bt cotton, pesticide use became specialized, only affecting insects that both were vulnerable to Bt’s toxin and that fed on cotton, which allowed the populations of other insect species to rebound. Some of the now-thriving species, like mirids, are pests, but others eat pests, and their recovery is making natural bug control possible.
Gallus gallus, the undomesticated ancestor of modern chickens
Chickens, the surviving descendants of once-mighty therapod dinosaurs, have come to dominate American dinner tables, where its meat is consumed at a rate of 80 pounds per person per year. How the wild grub-eating Gallus Gallus was tamed and commodified into frozen breaded cutlets is actually quite an epic story, one that involves (possibly) saving Greek civilization from Persians, the rise and fall of the Roman Empire, and continues today with KFC’s remarkable invasion of China.
Jerry Adler and Andrew Lawler have written a cover story for Smithsonian magazine on the taming of the chicken that delivers these tidbits and gives plenty more food for thought. It was the Egyptians, for example, who first figured out how to artificially incubate eggs, so they could be hatched without the presence of hens—a method so important that their methods were kept secret for centuries:
No, this isn’t Photoshop or a gemstone-studded trinket—just an ear of corn. Seedsman Greg Schoen of the Seeds Trust got this “Glass Gems” corn from his “corn-teacher,” a part-Cherokee man in his 80s. He planted the seeds, had a gorgeous harvest last fall, and posted the posts on Seeds Trust’s Facebook page in October. Then last week, the photos of the gem-like corn got picked up on the internet and went viral. Good luck trying to get your hands on any seeds now…
But kernel color is a fascinating—dare we say, colorful—topic in the annals of genetics research. For one, why are there so many vibrant colors in a single ear of corn? You don’t usually see flowers of different colors on a single tree. Each kernel is actually a different corn plant (or the seed of one) with a unique mix of genes inherited from its parents. That’s why counting up kernels of different colors in the more familiar purple and yellow corn cobs is a common way of teaching how pigment genes are inherited in Mendelian genetics.
The only thing worse than a huge stinking pit of manure may be a huge stinking and foaming pit of manure that blows up the barn. Over the past few years, explosions have destroyed several Midwestern pig farms, killing thousands of hogs and causing millions of dollars of damage. Pig farmers and scientists have been at a loss to explain these explosions. Could the culprit be a small microbe?
What’s the News: Parents going broke to pay for their offspring’s braces and orthodontistry can finally blame somebody besides their mildly malformed children: our farmer ancestors. A study published this week in the Proceedings of the National Academy of Sciences found that people living in subsistence farming communities around the world have shorter, wider jaws than those in hunting and gathering societies. This leaves less room for teeth, which have changed little in size or abundance over human history—and may help explain why crooked choppers and a need for orthodontia are so common, study author Noreen von Cramon-Taubadel tells the BBC. “I have had four of my pre-molars pulled and that is the only reason that my teeth fit in my mouth,” she says.
What’s the News: As human societies adopted agriculture, their people became shorter and less healthy, according to a new review of studies focused on the health impacts of early farming. Societies around the world—in Britain and Bahrain, Thailand and Tennessee—experienced this trend regardless of when they started farming or what stapled crops they farmed, the researchers found.
This finding runs contrary to the idea that a stable source of food makes people grow bigger and healthier. The data suggest, in fact, that poor nutrition, increased disease, and other problems that plagued early farming peoples more than their hunter-gatherer predecessors outweighed any benefits from stability.