Penguins have had quite the journey, from Australia some 22 million years ago to modern-day Antarctica, according to a new study. With help from institutions around the world, researchers at the University of California, Berkeley, analyzed blood and tissue samples from 18 species of penguins, finding that the animals originated in the temperate environments of what is now Australia and New Zealand during the Miocene period, "not in Antarctica as previously thought," per CNN. It's believed that ancestors of king and emperor penguins eventually veered into Antarctic waters, forming a sister group to other penguin lineages. Other penguins then permeated the Southern Ocean and surrounding areas around 12 million years ago with the opening up of the channel separating Antarctica and the southern tip of South America and the activation of a "clockwise current," per NPR.
The study published Monday in PNAS, which also uncovered an unknown penguin lineage, highlights the incredible adaptability of the animal, particularly in terms of regulating body temperature. Today, penguins swim in waters of subzero temperatures in Antarctica but waters of 79 degrees in the Galapagos Islands, per a release. They're also found in Australia and New Zealand, South America, the South Atlantic, southern Africa, and Indian Ocean islands. But "it has taken millions of years for penguins to be able to occupy such diverse habitats, and at the rate that oceans are warming, penguins are not going to be able to adapt fast enough to keep up with changing climate," says researcher Rauri Bowie. Warming oceans are hurting populations of krill, the penguins' main food, and devastating emperor penguins' breeding grounds. (See why emperor penguins need ice.)