Desert

Every year, about 27 million tons of dust blows from the Sahara desert across the Atlantic to the Amazon rainforest. The roughly 22,000 tons of phosphorus in this dust nearly matches what the Amazon loses to rain, making the world's driest place the fertilizer for its most lush.

The kangaroo rat is so adapted to arid environments that it barely drinks water. It produces 90% of its needed moisture through metabolic synthesis and even reabsorbs water vapor condensed in its nose. Drinking water directly can actually damage its kidneys.

A camel's hump stores fat, not water — and evolved for the Arctic, not the desert. 3.5 million years ago, ancestors in Arctic Canada grew fat-storing humps to survive winters. When they migrated south, the hump proved equally useful in the desert.