An island half the size of Manhattan in the South Atlantic is so isolated, it is called inaccessible island. On that island and only on that island, almost 6000 punctual feathers are known as inaccessible ashes. But they can not fly, and the island is only a few million years old. How did the birds get there?
A new analysis may have solved the mystery. The bird's DNA reveals that it has developed relatively recently from any visitor to the island and lost its ability to fly from the forces of the natural selection.
"It's quite spectacular that the word of the smallest live-flying birds ever ended up in one of the most remote places ever," the author Martin Stervander, postdoctoral researcher at the University of Oregon, told Gizmodo. "It seems that the birds arrived on the island, and because they were exposed to a small threat to predators, there was not much to fly."
When researchers first described the bird in the 1920s, they immediately knew that they looked at something weird. Unavailable island lies 3500 km from South America and 2800 km from southern Africa. The bird does not occupy any of the two neighboring islands less than 32 km away.
They suggested, before the theory of plate tectonics, that the bird in any way went to the island over any kind of sunken landbreed. They put it in their own family, Atlantisia . Recent research has suggested that the bird originates from rails in Africa.
The researchers behind the new paper have analytical tools other than bird shapes and geography at their disposal. They caught a male unavailable wish in September 2011, sampled their blood, sequenced their DNA, and compared the results with data on other rails.
They found that the ancestor of the railway was a South American bird that arrived on the island about 1.5 million years ago, and that it is more likely a member of the Laterallus family that includes today's birds as dot -winged crake, Galapagos crake and the similar black rail, according to the paper published in the journal Molecular Phylogenetics and Evolution.
It makes sense. Rails are famous for flying wherever and settling in, with 53 existing or newly extinct species, which are only displayed on islands, and 32 species lose one or all of their flying ability as a result. A population of the ancestors of the inaccessible oceans probably flew to the east of the Atlantic and ended up on the island – which was a pretty careful concert that they did not have to fly anymore.
"When the railroad came to the inaccessible island, they had all their food from going around and there was nothing to escape from, there is not much need to fly," said Stervander. The only threat to the inaccessible island is the bird species which sometimes eats eggs and maybe some bird birds.
It is unclear why the railroad did not cross to the other two islands – perhaps a population tried and failed.  Stervander pointed out that there is more research to be done. The data set on the rails was incomplete, so perhaps more data shows that the bird really belongs to a separate family.
And although the bird lives the good life, it is still considered a vulnerable species. Flightless bird populations can easily collapse if people carry invasive species with those who cats or rats.
This paper may solve the sweetest mystery in the South Atlantic. But if you plan to visit the island (which not an easy feat), make sure you do nothing to harm the birds.
[Molecular Phylogenetics and Evolution]