North America's rocks whisper tales of past life

摘要

Imagine a world where pigeon-sized dragonflies soar above spiders with half-meter-long legs, where 2-meter-long millipedes slither and 20-kilogram scorpions hunt. About 300 million years ago, such surreal creatures thrived; today, rocks hint at how these and other creatures in the deep past lived. These clues allow geologist and writer John Dvorak to vividly re-create ancient landscapes in How the Mountains Grew: A New Geological History of North America. Far from a dusty tome plodding through plate tectonics, the book teems with life as Dvorak establishes inextricable links between geology and biology. Take the oversize dragon-flies and millipedes now preserved as fossils. Rocks of a similar age hold evidence of a rise in atmospheric oxygen that helps explain how these animals grew so large.