A type of chicken-sized rail bird species, which was believed to have met with extinction almost 136,00 years ago, has come back. The scientists have mentioned this will mark the bird's 2nd appearance after the extinction due to the rare revolutionary process. Researches led to a conclusion that the species of the bird in the Indian Oceans has made their comeback through ‘iterative evolution’; the repeated evolution of similar or parallel structures from the same ancestor but at different times.
The University of Portsmouth in the United Kingdom and Natural History Museum researchers found out on two occasions in which the bird made its comeback and was able to colonize in islands such as Aldabra and the colonization was separated by tens and thousands of years, but both times they eventually became flightless. The white-throated rail is a chicken-sized bird, indigenous to Madagascar in the south-western Indian Ocean. These birds are indigenous colonizers of isolated islands for which reason after the population increased they felt the severe need find more atoll islands and went on towards north and south in search of solitary islands but couldn’t survive the expanse of ocean and perished. Out of those which went west, fell prey to predators in Africa, and the ones headed East, landed upon Mauritius, Reunion and Aldabra, a 400,00 years old ring-shaped coral atoll island.
With the absence of another life form on the isolated surfaces resulted in the evolution of the species as they lost their ability to fly. However, in a major inundation around 136,000 years ago, Aldabra Island met with its extinction and buried all he lives on the island underneath the ocean. Fossils before and after the inundation event have provided evidence of the bird’s wing bone to be in the advanced stage of flightlessness, and ankle bones showed distinct properties of evolving gradually towards flightlessness. This fossil has led to the evidence that the rails lost their flying abilities depending on their living in atoll islands. It can also be mentioned that, in this case, one species has given rise of 2 different species within the space of a few thousand years.