The white-throated rail was considered to be extinct about 136,000 years ago. However, in a bizarre and interesting fashion, the species of chicken-like bird has evolved all over again and returned to the previous home thus reclaiming the island where it used to live before going extinct. The scientists are amazed and say that it is almost as if the white-throated rail has managed to re-evolve itself back into existence.
The white-throated rail, before going extinct, had colonized the Aldabra Atoll in the Indian Ocean where it evolved and became flightless. Researchers have found fossils of before and after the white-throated rail became extinct. According to them, the bird re-appeared after the sea levels of the Aldabra Atoll took a dive again, a thousand years later with the bird claiming the real estate and forgoing its ability of flight.
If you make a trip to the Aldabra Atoll, you will see that the white-throated rail is currently living peacefully there and the species is flourishing. So, how did it come back from the dead? The process is known as iterative evolution. For those of you who are unaware, iterative evolution is the name given to the evolution that repeats of similar or parallel structures while developing the same main line. Put simply; it implies repeated evolution of a species from the same ancestor during different times in history.
What makes this so special is the fact that it is extremely rare and has been observed for the first time in rails. A study has been published in the Zoological Journal of the Linnean Society. This iterative evolution of white-throated rail has taken place thanks to the distinctive environmental factors of the region and the lack of natural predators of rail.
David Martill, the co-author of the study from the University of Portsmouth, said, ‘We know of no other example in rails, or of birds in general, that demonstrates this phenomenon so evidently. Only on Aldabra, which has the oldest palaeontological record of any oceanic island within the Indian Ocean region, is fossil evidence available that demonstrates the effects of changing sea levels on extinction and recolonization events.’
