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The preference of Heliconius butterflies for certain leaf shapes is innate, but can be reversed through learning. These results support a decades-old theory for explaining the evolution of the exceptional diversity of leaf shapes in passionflowers.

The tropical butterfly Heliconius eratodistinguishes between shapes, and uses them as a cue for choosing the plants on which to feed and lay eggs, shows new research by scientists from the University of Cambridge and the Smithsonian Tropical Research Institute. The butterfly has an innate preference for passionflowers with particular leaf shapes, but can learn to overcome this preference in favor of other shapes, especially those that are the most abundant in the local flora. These preferences can promote the evolution of plant biodiversity.

Researchers at the University of Illinois at Chicago have engineered a potentially game-changing solar cell that cheaply and efficiently converts atmospheric carbon dioxide directly into usable hydrocarbon fuel, using only sunlight for energy.

The finding is reported in the July 29 issue ofScience and was funded by the National Science Foundation and the U.S. Department of Energy. A provisional patent application has been filed.

Unlike conventional solar cells, which convert sunlight into electricity that must be stored in heavy batteries, the new device essentially does the work of plants, converting atmospheric carbon dioxide into fuel, solving two crucial problems at once. A solar farm of such "artificial leaves" could remove significant amounts of carbon from the atmosphere and produce energy-dense fuel efficiently.

BUILDING IN RHODE Island isn’t easy. Hurricanes and tropical storms barrel through its quaint coastline towns, interrupting perfect summer weekends. Freezing winters bring blizzards that can shut down the entire state. And every season features corrosive salty winds, biting at the coast as if sent by a Britain still seething at the first American colony to declare independence.

But one company sees the state’s incessant wind as a utility. Deepwater Wind has partnered with General Electric Renewable Energy to build the first offshore wind farm in the United States, off the coast of Block Island. Hooked up to the grid by the end of 2016, the system could supply 90 percent of the tourist destination’s power within the next few years. But it hasn’t been easy. Designing and building spinning fans hundreds of feet tall that stay sutured to the ocean floor in the face of currents and wicked winds has taken almost three years of work.

A new study of over 1 million people finds that doing at least one hour of physical activity per day, such as brisk walking or cycling for pleasure, may eliminate the increased risk of death associated with sitting for 8h a day.

Physical inactivity is linked to an increased risk of heart disease, diabetes and some cancers and is associated with more than 5 million deaths per year and, as the first global economic analysis of physical inactivity shows, costs the world economy over US$67.5 billion per year in health care costs and lost productivity.

A new acoustic buoy recently deployed by scientists from the Woods Hole Oceanographic Institution (WHOI) and WCS's (Wildlife Conservation Society) New York Aquarium to listen for some of the world's biggest animals in the New York Bight has detected its first whale species, and it's a really big one.

Fixed in position some 22 miles south of Fire Island and fitted with a digital acoustic monitoring instrument, the hi-tech buoy is now operational and has detected the vocalizations of fin whales, enormous marine mammals second in size only to the blue whale, the largest animal species on earth. The first whale detection was made on Monday, July 4th, only 12 days after the buoy was placed in its current position on June 23rd.

Since that time, the buoy has made several fin whale detections; the most recent vocalizations were detected yesterday (July 27th) and today.