Take a Deep Breath and Say Hi to Your Exposome

Pig-Pen in his element (Illustration: Charles M. Schulz)

by Richard Conniff/Scientific American

Over the past few decades, researchers have opened up the extraordinary world of microbes living on and within the human body, linking their influence to everything from rheumatoid arthritis to healthy brain function. Yet we know comparatively little about the rich broth of microbes and chemicals in the air around us, even though we inhale them with every breath.

That struck Stanford University genomics researcher Michael Snyder as a major knowledge gap, as he pursued long-term research using biological markers to understand and predict the development of disease in human test subjects. “The one thing that was missing was their exposure” to microbes and chemicals in the air, Snyder says. “Human health is clearly dependent not just on the genome or the microbiome, but on the environment. And sampling the environment was the big hole.”

In a new study published September 20 in Cell, Snyder and his co-authors aim to fix that, with a wearable device that monitors an individual’s daily

How China Could Lead the World in Getting Reforestation Right

A site in Sichuan that’s part of the world’s largest reforestation project. (Photo: Eye Ubiquitous/UIG via Getty Images)

by Richard Conniff/Takepart

What if you undertook the world’s largest reforestation program but planted the wrong trees? That’s what China’s been up to.  Since 1999, it has spent $47 billion planting trees on 69.2 million acres of abandoned farm fields and barren scrubland.

That’s an area almost equivalent to New York and Pennsylvania combined—and should be great news in an era of worldwide deforestation. Moreover, from China’s point of view, the program has succeeded at its original purpose, controlling soil erosion. But the vast majority of the new forests consist of only a single tree species, according to a new study in the journal Nature Communications. That is, China has been creating tree plantations—monocultures, not forests—and with nonnative trees. That choice has sacrificed one of the major benefits of healthy forests: diversity of plants and wildlife.

The study, led by Princeton University researchers, puts an optimistic spin on these findings. The coauthors argue that China could

When the Killing’s Done, Island Wildlife Roars Back

The world’s only oceanic hummingbird, the Juan Fernandez Firecrown. (Photo: Island Conservation)

My latest for Takepart.com:

For conservation biologist Holly Jones, one of the best experiences of her work on island wildlife was the night she went out hunting for a rare lizard-like creature called the tuatara on Stephens Island in New Zealand. The place was cacophonous with seabirds, which also happened to be attracted to her headlamp. At one point, she found herself sitting in the dark with birds in her lap, at her shoulders, and flapping endlessly around her head. It was like Hitchcock’s The Birds, she said, except that she was ecstatic to be part of this island explosion of life.

Stephens Island happens to be the site one of the most notorious episodes in the history of humanity’s enraptured—but rocky—affair with islands. In 1894, a crew of lighthouse keepers arrived there, bringing a cat named Tibbles with them. The cat was soon coming back to the lighthouse with small, flightless birds in its teeth. One of them turned out to be a new species, the Stephens Island Wren. Within a year or two, a rapidly expanding community of cats had driven it to extinction. By 1897, there were so many cats killing so many birds that a lighthouse keeper urged the authorities “to employ some means to destroy them.” It took another 27 years, but the successful effort to eradicate the cats was the chief reason such an abundance of seabirds survived to greet Holly Jones that night on Stephens Island.

What happened there is now standard conservation practice around the world to protect the incredible diversity of species on islands. Jones, an assistant professor at Northern Illinois University, is the lead author on a study published Monday in the Proceedings of the National Academy of Sciences that looks at the long-term effects of eradicating cats, rats, goats, pigs, and other invasive mammals from islands. On the 181 islands where biologists have conducted follow-up studies, Jones and her coauthors found that eradication turns out to be

Saving Wildlife is Good for Your Health (But It’s Complicated)

(Photo: Wolfgang Kaehler/LightRocket via Getty Images)

I live in one of the towns that gave Lyme disease its name, and yet I also love wildlife. So I rejoiced a few years ago when a study argued that maintaining healthy natural habitats with a rich diversity of wildlife can help keep people healthy, too, by protecting us from infectious diseases. Now two new studies out this week support this theory—though skeptics say they still have their doubts.

The basic idea, first proposed by ecologists Richard Ostfeld and Felicia Keesing, is called the “dilution effect,” and it works like this: for a given disease affecting multiple species—like Lyme disease or malaria—some host animals readily transmit the disease organism to the tick or mosquito that will carry it to the next victim. But other species are dead ends.

In the case of Lyme disease in the western United States, for example, western gray squirrels readily contract the bacteria and pass it on to ticks. But when those same ticks feed on western fence lizards, it kills the Lyme-causing bacteria in the ticks’ blood. That makes the lizards a bad host for Lyme, and good for us. In theory, the greater the biodiversity in any habitat, the more chances

Highways as the Last Hope for Some Wildlife

Everywhere in the world people are moving to cities and suburbs, covering the landscape in houses, highways, office developments, and strip malls.  Just in the lifetimes of today’s 20-somethings, urban coverage in the lower 48 states will more than triple–from 2.5 percent to 8.1 percent of the landscape by 2050.  In some Northeastern states, according to the U.S. Forest Service, the land will be more than 60 percent urban by mid-century, up from about 35 percent now.

So where will plants and animals fit in this crowded world?  Nowhere at all, unless planners figure out how to make a place for them.  It may be a mark of desperate times, but many conservationists are now looking to the sides of highways as the only place left for some species to live.

The United States has four million miles of highways, most of them with substantial unpaved medians and margins. Planting grass is the standard treatment, partly because that’s how the guys in the highway department have always done it, and partly because political patronage at the county level drives the investment in machinery and gasoline. But a few states now take a greener approach.

In Iowa, for instance, the wall-to-wall planting of corn means hardly any of the original prairie habitat has survived. So that state has become a leader at … to read the rest of this story, click here.

Naked Tahitian Beauty

In the West, we’ve always thought of Tahiti as a hot spot, populated by bronzed beauties.  And now it turns out to be true, though maybe not in the way you were thinking.  Here’s the news, from ScienceDaily:

A bronzed Tahitian beauty named Mecyclothorax ramagei. (Photo: James K. Liebherr)

Picturesque Tahiti may be the hottest spot for evolution on the planet. A recent biological survey of tiny predatory beetles has found that over 100 closely related species evolved on the island in about 1.5 million years. Given Tahiti’s small area, slightly more than 1000 square kilometers, this adaptive radiation is the geographically densest species assemblage in the world.

The predatory beetles range in size from 3-8 mm long, and have evolutionarily lost their flight wings, making them homebodies living in small patches of mountain forest.

“It is exhilarating working with such a fauna, says James Liebherr of Cornell University, author of a new report in the journal Zookeys, “because every new locality or ecological situation has the high probability of supporting a species nobody has seen before.”

These beetles have diversified by speciating as fast as any animals worldwide, with each species estimated to last only 300,000 years before splitting into daughter species. Tahiti’s geological history has much to do with this evolutionary rate, as these beetles prefer to live in rain forests on high mountains.  Their mountain territitories tend to become isolated through the same extensive erosion that has produced the broad, low-elevation river valleys so characteristic of the island. Yet some closely related species live on the same mountain ridge, just at different elevations or in different types of habitat.

This level of specialization is what characterizes an adaptive radiation, where species exist within narrow ecological or geographic boundaries that mainland species would simply ignore or fly over.

Yet this exuberant evolution may face a dark future, as invasive species from the mainland threaten the highly specialized island species. Predatory ants, such as the little fire ant, have invaded Tahiti, and have been recorded from some localities where native beetle species were collected by French entomologists in the 1970s.

“Now that the 101 species of small predatory beetles currently known from Tahiti can be identified, field sampling can be used to evaluate their conservation status relative to alien threats,” says Liebherr.

Finally, Liebherr offers one piece of travel advice that I have always endeavored to follow: Go, my son, but go pest-free.  No, seriously:

 “Everybody who makes landfall on Tahiti, either by air or sea, should endeavor to disembark pest free so as to protect the many denizens of the mountain forests who make the native ecosystems work.”

Source: James Liebherr. The Mecyclothorax beetles (Coleoptera, Carabidae, Moriomorphini) of Tahiti, Society Islands. ZooKeys, 2013; 322: 1