The birds’ ancestors may have fled to warmer digs
Ancestors of the world's formally attired flightless birds may have booked it from the South Pole around 12 million years ago to escape a cold spell.
The find, which researchers report November 12 in Biology Letters, clarifies penguins’ history. Previously, scientists had pegged the origin of penguins to somewhere between 10 million and 50 million years ago, with members of the bird family scattering between Antarctica and the tropics sometime later.
In the most comprehensive study to date, David Lambert of Griffith University in Nathan, Australia, and colleagues analyzed penguin fossils and the sequences of five genes from all living groups of penguins. The results suggest that penguins' common ancestor appeared in Antarctica around 20 million years ago.
The researchers also found that the major groups of living penguins began branching off between 16 million and 11 million years ago. The timing overlaps with a climate shift around 12 million years ago that cooled Antarctica. The icier temperatures may have spurred the migration and evolution of some penguin species, the researchers suggest.