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Monday, November 23, 2009

Photo: Giant Bugs a Thing of the Past, Study Suggests


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An x-ray image of a darkling beetle shows the animal's respiratory system. As an insect gets bigger, the proportion of its body dedicated to breathing increases rapidly, a new study shows.

This suggests that insects can't reach the giant sizes they did 300 million years ago, because today's atmosphere has much less oxygen than it once did.

Image courtesy PNAS