Over 60 million years ago, penguins abandoned flight for swimming. Here’s how.

Penguins are perhaps best known for being flightless birds whose wings help them “fly” through frigid Antarctic waters. But penguins lost their ability to fly and instead became streamlined swimmers some 60 million years ago, long before the Antarctic ice sheet formed — and researchers have now revealed how that happened.

A new study of penguin fossils and the genomes of current and recently extinct penguins identified an array of genetic adaptations the birds made to live an aquatic lifestyle; from vision that is sensitive to underwater blue tones to genes related to blood oxygenation, and even to changes in bone density. Together, the findings suggest that penguins as a group adapted to survive some serious environmental changes that unfolded over millions of years.

From flight to flightless

Leave a Comment