ALDABRA ISLANDS (National Geographic) – A team of researchers from the University of Portsmouth and the Natural History Museum in London confirmed that a bird that became extinct more than 130,000 years ago reappeared the island of Aldabra, north of Madagascar, Africa. This could be corroborated after comparing several fossils. This study was published in the Zoological Journal of the Linnean Society.
What is the curious story of this bird?
The white-throated ralids, which colonized Aldabra Atoll in the past, became extinct when the island disappeared under some 136,000 years ago. This type of bird evolved and lost its ability to fly. Therefore, it could not escape.
The white-throated reds lost the ability to fly because the lack of predators made it unnecessary. Then, thousands of years later, when the sea level dropped again, and the island resurfaced, birds the size of chickens reappeared, re-colonized the island, and also lost the ability to fly.
For this reason, this bird is one of the most important examples of what is known as iterative evolution. This means the repeated evolution of a species from the same ancestor at different times in history. Researchers found similar fossils from before and after the atoll sank and reappeared.
“We do not know of any other examples in the paleontology, or in birds, that demonstrate this clear phenomenon,” co-author David Martill, of the University of Portsmouth, said in a CNN statement.
“These unique fossils provide irrefutable evidence that a member of the ralid family colonized the atoll, probably from Madagascar, and became a flightless bird on each occasion,” explained the study’s lead author, Julian Hume, in a statement from the Natural History Museum in London.