A bird that previously went extinct for the past 136,000 years has risen back up from the dead through evolution, amazing the scientists all across the world.

The rise from extinction of a chicken-sized, flightless, white-throated rail bird species in the Indian Ocean became possible through a rare evolutionary process known as ‘Iterative Evolution’ – the repeated evolution of similar or parallel structures from the same ancestor but at different times.

Fossils found suggest that the flightless white-throated rail bird lived on the Madagascan island tens of thousands of years ago and went extinct for three times. The rails migrated from Madagascar in all directions, however, those that landed on the island of Aldabra lost their ability to fly due to the absence of predators, as per Buzzfeed News.

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However, changing sea levels twice inundated and killed everything on the island some 136,000 years ago. But, the team researched the effects of changing sea levels on extinction and re-colonization. It discovered that on two occasions separated by thousands of years, the rail species successfully colonized on Aldabra and later became flightless on both occasions. The last surviving colonies of those birds are still found on the island today, reported Deccan Chronicle.

Lead researcher Julian Hume, said, “These unique fossils provide irrefutable evidence that a member of the rail family colonized the atoll, most likely from Madagascar, and became flightless independently on each occasion.”

The team compared the bones of a fossilized rail from the inundation event with bones from a rail after the event. They discovered that the wing bone showed an advanced state of flightlessness and the ankle bones showed distinct traits that it was evolving towards flightlessness.

“Conditions were such on Aldabra, the most important being the absence of terrestrial predators and competing mammals, that a rail was able to evolve flightlessness independently on each occasion,” said co-author David Martill. “We know of no other example in rails, or of birds in general, that demonstrates this phenomenon so evidently.”