(CNN)When you think of the penguin, the image that pops to mind is usually the fuzzy bird waddling through snow or swimming in frigid Antarctic waters.
But penguins didn't originate in Antarctica, as scientists have believed for years -- they first evolved in Australia and New Zealand, according to a new study by researchers at the University of California, Berkeley.
The study, which was conducted in collaboration with museums and universities around the world, analyzed blood and tissue samples from 18 different species of penguins. They used this genomic information to look back in time, and trace the penguins' movement and diversification over millennia.
"Our results indicate that the penguin crown-group originated during the Miocene (geological period) in New Zealand and Australia, not in Antarctica as previously thought," said the study, published on Monday in the Proceedings of the National Academy of Sciences. "Penguins first occupied temperate environments and then radiated to cold Antarctic waters."
Penguins originated in Australia and New Zealand 22 million years ago, researchers suggest; then, ancestors of the king and emperor penguins split off and moved to Antarctic waters, likely attracted by the abundant food supply there.
These findings also support the theory that king and emperor penguins are the "sister group" to all other penguin lineages -- adding another piece to the long-debated puzzle on where exactly these two species sit on the family tree.
Then about 12 million years ago, the Drake Passage -- the body of water between Antarctica and the southern tip of South America -- fully opened up. This allowed the penguins to swim throughout the Southern Ocean, and spread more widely to sub-Antarctic Islands as well as the warmer coastal regions of South America and Africa.
Today, the flightless birds are still found in Australia and New Zeal