When I think of birds that have gone extinct, the first images
that come to mind are the elephant bird, the passenger pigeon, and of course the dodo.
All of these are gone because people were careless. But humans aren’t the only
reason for extinction. In fact, species were disappearing millennia before we
came on the scene, birds included. The Aldabra white-throated railbird was one
of these, presumed to have vanished more than 100,000 years ago because of
rising sea levels. Surprisingly, the Aldabra railbird seems to have made a
comeback, because of a phenomenon called, “iterative evolution.” The Aldabra’s
genes have been dormant in almost-but-not-quite identical offspring, waiting to
reassemble in just the right way. Essentially, the Aldabra white-throated
railbird has evolved twice. Scientists have observed iterative evolution in
other species, such as turtles. This is the first time we’ve documented a
re-evolved bird. Maybe I’ll have a pet dodo someday after all.
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