Tag Archives: organisms

Fetch, Boy! Study Shows Homes with Dogs Have More Types of Bacteria

New research from North Carolina State University and the University of Colorado shows that households with dogs are home to more types of bacteria – including bacteria that are rarely found in households that do not have dogs. The finding is part of a larger study to improve our understanding of the microscopic life forms that live in our homes.

 “We wanted to know what variables influence the microbial ecosystems in our homes, and the biggest difference we’ve found so far is whether you own a dog,” says Dr. Rob Dunn, an associate professor of biology at NC State and co-author of a paper describing the work. “We can tell whether you own a dog based on the bacteria we find on your television screen or pillow case. For example, there are bacteria normally found in soil that are 700 times more common in dog-owning households than in those without dogs.” (more…)

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Biodiversity Protects Against Disease, Scientists Find

Discovery resulted from study of amphibians in ponds

The richer the assortment of amphibian species in a pond, the more protection that community of frogs, toads and salamanders has against a parasitic infection that can cause severe deformities, including the growth of extra legs.

The findings, published in a paper in this week’s issue of the journal Nature, support the idea that greater biodiversity in large-scale ecosystems, such as forests or grasslands, may also provide greater protection against diseases, including those that affect humans.

A larger number of mammal species in an area may curb cases of Lyme disease, while a larger number of bird species may slow the spread of West Nile virus. (more…)

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Confirmed: Stress Gradient Hypothesis: How Plant Communities Endure Stress

The Stress Gradient Hypothesis holds that as stress increases in an ecosystem, mutually supportive interactions become more significant and negative interactions, such as competition, become less so. The idea has been hotly debated but is now backed by a review of hundreds of studies co-authored in Ecology Letters by Mark Bertness, professor of biology at Brown, who first formally proposed the hypothesis in 1994. The time has come, he said, to test its application and predictive value.

PROVIDENCE, R.I. [Brown University] — Ecology is rife with predation, competition, and other dramatic “negative interactions,” but those alone do not determine the course life on Earth. Organisms sometimes benefit each other, too, and according to the Stress Gradient Hypothesis, their “positive interactions” become measurably more influential when ecosystems become threatened by conditions such as drought. Ecologists have argued about the hypothesis ever since Brown University ecologist Mark Bertness co-proposed it in 1994; Bertness says a large new global meta-analysis he co-authored in Ecology Letters definitively shows that it is true. (more…)

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Flies of the World Embrace Vegetarianism

Microbe-eating flies from at least three different locations around the world recently have evolved into herbivores, feeding on some of the most toxic plants on Earth. Fly detectives and UA evolutionary biologists Noah Whiteman and Richard Lapoint are trying to find out what genetic pathways led the flies to such a major change of lifestyle.

For millennia, they buzzed through the woods, contentedly munching yeasts off the surfaces of leaves, bracken and rotting duff on the forest floor. But now, flies in the family Drosophilidae, whose disparate members dwell in areas all across the planet, have evolved into all-out vegetarians with a wicked diet of plants that are deadly to most other organisms.

What, University of Arizona scientists would like to know, has caused these flies, yeast-feeders for nearly 80 million years, to independently go cold turkey with respect to their formerly meaty diets? (more…)

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Yale Researchers Find New Cause of Climate Change: Trees

Researchers at the Yale School of Forestry & Environmental Studies have discovered that diseased trees may be a significant cause of global warming. The university’s researchers tested the trees at the Yale Myers Forest near their campus in Connecticut and discovered that rotting trees release a significant amount of methane gas, a highly flammable type of natural gas that can cause climate change in large quantities. The trees at the Yale Myers Forest produce emissions that are equivalent to burning 40 gallons of gas per acre of forest per year.

In their academic report on this matter, “Elevated Methane Concentrations in Trees of an Upland Forest,” the Yale University research team noted that trees that release methane gas look just like ordinary trees on the outside. However, on the inside, they’re being eaten alive by fungus. And the fungus that rots these trees helps fuel methane production because it makes the trees a hospitable breeding ground for methanogens, tiny organisms that create methane. (more…)

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CU-Boulder-led Team Finds Microbes in Extreme Environment on South American Volcanoes

A team led by the University of Colorado Boulder looking for organisms that eke out a living in some of the most inhospitable soils on Earth has found a hardy few.

A new DNA analysis of rocky soils in the Martian-like landscape on some volcanoes in South America has revealed a handful of bacteria, fungi and other rudimentary organisms called archaea, which seem to have a different way of converting energy than their cousins elsewhere in the world.

“We haven’t formally identified or characterized the species,” said Ryan Lynch, a CU-Boulder doctoral student involved in the study. “But these are very different than anything else that has been cultured. Genetically, they’re at least 5 percent different than anything else in the DNA database of 2.5 million sequences.” (more…)

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Yale Research Reveals Ancient Moth’s True Colors

A research team led by Yale University scientists has for the first time determined the original colors of an ancient moth, based on nearly 50 million-year-old fossils from Germany.

The discovery could help scientists learn the colors of a wide variety of long-extinct creatures, including birds, fishes, and other insects, and shed light on color’s function and evolution. (more…)

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