Flightless Bird's 3,500km Journey to Remote Island Solved by DNA

Inaccessible Island, one of the most isolated islands in the world, located in the South Atlantic Ocean, is home to the world's smallest flightless bird, the Inaccessible Island rail (Atlantisia rogersi). For nearly a century, scientists have been puzzled about how this tiny bird, weighing just 30 to 40 grams, managed to inhabit an island thousands of kilometers from any mainland. This long-standing mystery has now been solved through cutting-edge DNA analysis led by evolutionary biologist Martin Stervander and his team. Their findings were published in the journal *Molecular Phylogenetics and Evolution*. Previously, the prevailing hypothesis, proposed in the 1920s by ornithologist Percy Lowe, suggested that the bird's ancestors walked across ancient land bridges that once connected continents before they submerged. However, modern DNA sequencing and comparison with genetic material from various bird relatives worldwide have debunked this theory. The research indicates that the ancestors of the Inaccessible Island rail likely undertook an incredible journey of over 3,500 kilometers by sea from the South American continent approximately two million years ago. This remarkable long-distance migration is believed to have occurred during an early stage before the species lost its ability to fly. Once established on the island, in the absence of predators, the birds gradually evolved to lose their flight capabilities. The steep cliffs and extreme conditions of Inaccessible Island make it a place rarely visited by humans. This geographical isolation has created the perfect environment for unique species like the Inaccessible Island rail to evolve and survive.