Take a deep breath in. Slowly let it out.
You have just participated in one of the most profound evolutionary revolutions on Earth—breathing air on land. It’s unclear how the first vertebrates thrived after crawling out of the sea nearly 400 million years ago, but the lungs hold an important clue.
Birds, reptiles, mammals and amphibians have evolved diverse lung structures through which air flows in complicated ways. Birds and mammals are … Read more