Sunday, February 14, 2010

Discover Magazine, March 2010

Two completely absorbing articles from the current issue of Discover:

Grayish-brown wild horses fighting against a green wetland plain
Where the Wild Things Are by Andrew Curry

This story left me reeling, and wanting to get on the first plane to Amsterdam.

Accompanied by incredible photos like the one above by Terry Whittaker, it tells about a place 20 miles north of that city. It has been reclaimed from the sea by one of Holland's many dikes and turned back to nature to become a living laboratory, showing what Europe may have been like before agriculture.

The surprising part is that the area is not becoming a primeval forest -- in fact, it's open plains and wetlands, where the encroaching trees are kept under control, naturally, by animals that were introduced to mimic the species that evolved in Europe: horses, deer, geese, cattle. It's a successful experiment in rewilding by a Dutch ecologist named Frans Vera, and the area is called Oostvaardersplassen (which means "lakes of the ones who sail east").

Vera's thinking, and the outcome at Oostvaardersplassen, seem obvious once described and demonstrated. Curry writes:

The more Vera considered [the primeval forest] model, the less sense it made. If prehistoric Europe was densely forested, how had meadow-loving geese evolved in the first place, without people mowing to keep their habitat open? How had grazing animals thrived in shadowy, thick woods, let alone evolved to prefer grass?
Geese arrived in Oostvaardersplassen on their own soon after the area was drained in the early 1970s. Through his position with the Dutch forest service, Vera helped introduce Heck cattle, which had been bred to approximate the prehistoric aurochs, in 1983. In 1984, konik ponies were introduced; red deer were added in 1992.

All these species began with populations well under 100 each. Today there are over 3,000 deer, cattle and horses in the reserve, and their populations have been stable annually for the past five years. They get no extra shelter or food in the winter, and up to 20 percent die each year of starvation (although rangers with rifles provide a quick end to animals that are "clearly too weak to survive another week"). Their carcasses are left for the foxes and carrion birds; Oostvaardersplassen is now home to the first pair of nesting white-tailed eagles in the Netherlands since the Middle Ages.

All this reminds me of the people working to reintroduce the buffalo to the plains of North America, and of the lost passenger pigeon whose flocks blackened the sky. All those birds were eating something, and it wasn't fully grown trees.

A few final words from Curry:
It may take quite a few...demonsrations to establish the idea that closed-canopy forests, which most people regard as the normal state of nature, may actually be man-made. In fact, those forests are forbidding places for migratory birds. The forest floor is too barren to support large numbers of grazers, and the canopy is too dense to let light-hungry trees like oaks sprout and grow. They are leafy desserts.

Yet traditional forest management ususally winds up culling deer and bison -- not to mention beavers and boar -- when their behavior srtarts to affect trees. "The tragedy is that biodiversity is sacrificed on the altar of the closed-canopy forest," Vera says. "There's this crazy idea that no animals should damage trees, as if trees are made by God to to be eaten."
The Discover Interview: Barry Marshall by Pamela Weintraub

Marshall is the Australian doctor who, along with pathologist Robin Warren, figured out that ulcers are caused by bacteria, rather than stress. And that stomach cancer comes from the same source. They won the 2005 Nobel Prize for medicine for their work.

Barry Marshall and Robin Warren
Marshall (left) and Warren

Some favorite bits from the interview:
  • Before Marshall and Warren's discovery, ulcers were a cash cow for gastroenterologists and surgeons, who would slice off the bottom of the stomach and reconnect the intestine. "These problems were so common that the Mayo Clinic was built on gastric surgery."
  • Warren is the one who had noticed the presence Heliobacter pylori in the biopsies of ulcer and cancer patients. He suggested it to Marshall, who needed a project during his training as an internist.
  • The reason pathology had not turned up the bacteria before this was because H. pylori is slow to culture, and the pathologists had been throwing out the samples after a day or two, since that's how long it takes for bacteria like strep to develop.
  • After presenting their results and writing letters to The Lancet, Marshall and Warren weren't having any impact. They knew that both surgeons and drug companies had vested interests in maintaining the surgery and antacids status quo.
  • They couldn't do human trials, so Marshall performed a trial on himself by drinking a culture from one of his patients' stomachs. Within five days he began vomiting, and by the 10th day had an endoscopy that showed the bacteria was everywhere. He took antibiotics and it went away.
Marshall is convinced that almost every human has or had H. pylori, although some are asymptomatic for ulcers. "At first I thought it must have been a silent infection, but after I had it, I said, 'No, it's actually an infection that causes vomiting.' And when do you catch such infections When you're toddling around, eating dirty things and playing with your dirty little brothers and sisters. The reason you didn't remember catching Heliobacter is that you caught it before you could talk."

And H. pylori, with its accompanying ulcers and cancer, aren't the only things we might be picking up in childhood, Marshall says. "[When the kids were 2] every week they'd come home with a different virus. You didn't know what the infection was. The kids had a fever for two days, they didn't sleep, they were irritable, and then it was over. Well, you think it is over. It might be gone, but it has put a scar on their immune system. And when they grow up, they've developed colitis or Crohn's disease or maybe eczema. There are hundreds of diseases like this, and no one knows the cause. It might be a germ, just one you can't find."

Marshall hopes for an NIH grant to launch a large, longitudinal study, where children would be followed from birth. Each month each of 10,000 children would have a cheek swab and a stool sample. With every fever, a cheek swab would be taken. "Then in 20 years' time, we would find that 30 of them developed colitis, and we would go back. If we could get all of that material out of the deep freeze and run it through the sequencing machine, we would find the answer."

Marshall also is working on a way to use Heliobacter for good -- as a vehicle for creating a cheaper, more efficient flu vaccine. He's looking for a strain of the bacteria that causes no symptoms. "Then we'll take the influenza surface protein and clone that into Heliobacter and figure out how to put it in a little yogurt-type product. You just take one sip and three days later the whole surface of your stomach is covered with the modified Heliobacter. Over a few weeks, your immune system...starts creating antibodies against influenza..." Why is this better than the current vaccines? "...with a home brew kit, I can make 100,000 doses in my bathtub. [With this method] a vaccine against malaria would be dirt cheap. You could make 100 million doses in the middle of Africa without a refrigerator."

5 comments:

Ms Sparrow said...

Wow, I'm regretting dropping my subscription to Discover in favor of Natl Geographic. Those are both really interesting articles. Thanks for the update!

Blissed-Out Grandma said...

Really interesting! Thanks for posting so many informative pieces.

elena said...

Fascinating posts, DN3: thank you for discovering these, and augmenting them with such insightful writing.

vegaia said...

Here's why Jonathan Safran Foer is going vegan! Check out this informative and inspiring video.
http://veganvideo.org/

Blythe said...

I spent a day looking for koniks in Holland. I saw deer, many birds, and a much water. Someday I'm going to visit the bison of Poland and the wildlife around Chernobyl--then I'm going to stay in the Dutch swamps long enough to see my konik.