Although scientists claim that 'iterative evolution' has often been observed in many animals, like sea cows, ammonites, and sea turtles -- but what they witnessed with the Aldabra bird is beyond comprehension.
In what can only be described as an aftermath of a quirky evolutionary process, a bird that had gone extinct around 136,000 years ago has made a comeback! How unbelievable is that? As unreal as it sounds, it did happen with the Aldabra white-throated rail that once lived in the Indian Ocean. Although the bird isn't much to look at, especially with its dull-colored feathers and tiny body -- but the mere fact that it has somehow evolved back into existence has blown not only our minds but even researchers and experts, reports VICE.
"We know of no other example in rails, or of birds in general, that demonstrates this phenomenon so evidently," the study's co-author, University of Portsmouth professor David Martill, said in a statement. "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." As reported by Fox News.
One more amazing story of not ONE, but TWO flightless rails!— Lucile Leveque (@lucile_leveque) May 9, 2019
The white-throated rail from Madagascar became flightless on Aldabra, died out due to rising sea levels 20,000 years ago, and repeated the process again.https://t.co/rk6lrmN4Mf
The flightless railbird was spotted on the island of Aldabra. The fossils found on the island indicate that the bird lived there thousands of years ago, but couldn't survive as it could not move to higher grounds, especially during the rising sea levels. However, as scientists would call it, the "iterative evolution" has now led to similar body parts having been evolved due to genetics from a similar ancestor. This means, the bird literally came back from the dead!
The study's abstract gives details on how it happened. "A flightless Dryolimnas has been identified from two temporally separated Aldabran fossil localities, deposited before and after the inundation event, providing irrefutable evidence that a member of Rallidae colonized the atoll, most likely from Madagascar, and became flightless independently on each occasion," the abstract reads.
The Aldabra brush warbler was endemic to the atoll of Aldabra in the Seychelles and an individual was last seen in 1983.— Extinct Animals (@ExtAnimals) August 14, 2018
Possible reasons for its extinction could be attributed to the presence of rats, cats and goats brought to the atoll.#ExtinctAnimals #extinct #bird #biology pic.twitter.com/mxm9mx2zxh
"Fossil evidence presented here is unique for Rallidae and epitomizes the ability of birds from this clade to successfully colonize isolated islands and evolve flightlessness on multiple occasions."
The research has been published in the scientific journal, Zoological Journal of the Linnean Society. Although scientists claim that 'iterative evolution' has often been observed in many animals, like sea cows, ammonites, and sea turtles -- but what they witnessed with the Aldabra bird is beyond comprehension.
"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 study's lead researcher, Dr. Julian Hume added in the statement. "Fossil evidence presented here is unique for rails, and epitomizes the ability of these birds to successfully colonize isolated islands and evolve flightlessness on multiple occasions."
New research from @UOP_SEES Dave Martill & Julian Hume of @NHM_London on repeated evolution of flightlessness among rails from Aldabra Atoll in the Indian Ocean #FossilFriday @uopresearch https://t.co/AClWM7eK6L— SEES, University of Portsmouth (@UOP_SEES) May 10, 2019
With human solely responsible for climate change and the effect it has on the environment, sea levels have been constantly rising over the years. This means that modern Aldabra might face the same fate as its ancestors unless we do enough to keep the environment from deteriorating. But you never know, a third generation of the flightless bird might just eventually reappear in some far off atoll.