Like an engineer accounting for a skyscraper swaying in the wind, Madagascar's Darwin's bark spider (Caerostris darwini) spins enormous, river-spanning webs that stretch and contract as the trees to which they're anchored bend this way and that. A new study finds that this spider's silk is the toughest biomaterial yet discovered.

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Each person's gut carries a different collection of bacteria-infecting viruses that may benefit their hosts, researchers report. The viruses contain DNA fragments whose functions include cell repair and food processing.

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Great Danes stretch more than a meter from paw to shoulder and can easily weigh more than 90 kilograms. A Chihuahua fits snugly inside a purse. Domestic dog breeds are more varied in body size and shape -- not to mention coat color and fur length -- than any other land-based mammal. Yet, according to a new study, a mere two to six regions in doggy DNA account for most of this diversity.

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This article and associated material/lesson plan can be used to identify the structure and function of mitochondria and to understand mitochondria's role in evolution.

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This article describes the first truly photosynthetic animal reported; the Green Sea Slug. Cells in its digestive tract hijacks chloroplasts from algae it feeds on, preserve functionality of these chloroplasts in slug cells, and produce food by photosynthesis. Moreover, some genes important for maintaining photosynthetic function of these hijacked chloroplasts are believed to have transferred...

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