Birds and mammals are on extreme ends of the airflow spectrum. Mammals inhale oxygen-rich air and they exhale depleted air, exhibiting a so-called tidal flow pattern. In contrast, bird breath travels ...

Air quality alerts in North Alabama were at unhealthy levels Monday, thanks in part to what appears to be traces of Canadian wildfire smoke being pushed southward across the continent due to unusual ...

This is an archived article and the information in the article may be outdated. Please look at the time stamp on the story to see when it was last updated. Temperatures set to rebound from prolonged ...

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 ...