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



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


NEWS FEEDS    After installing a news reader, click on this icon to download National Geographic News's XML/RSS feed. After installing a news reader, click on this icon to download National Geographic News's XML/RSS feed.

Get our news delivered directly to your desktop—free.
How to Use XML or RSS

ADVERTISEMENT

NATIONAL GEOGRAPHIC'S PHOTO OF THE DAY

50 Drives of a Lifetime

Listen to your favorite National Geographic news daily, anytime, anywhere from your mobile phone. No wires or syncing. Download Stitcher free today.