In a first spectacle ever discovered by scientists, new bird species belonging to the "Big Bird" lineage in the Galapagos Islands have evolved into a new species in just two generations, according to a study.
Rosemary Grant, senior biologist at Princeton in the U.S., said: "Through our work on Daphne Major, we were able to observe the pairing up of two birds from different species and then follow what happened to see how speciation occurred".
Professors Rosemary and Peter Grant of Princeton University collaborated with Prof Leif Andersson of Sweden's Uppsala University to genetically analyze the mixed-species population, and published their findings in Science journal on November 23.
The new species of Darwins finch was observed during field work carried out over the last four decades by B Rosemary and Peter Grant, two scientists from the Princeton University in the U.S., on the small island of Daphne Major. The isolated island helped the biologists to study evolution due to natural selection. When they noticed a odd bird with a largish beak and unusual song on Daphne Major, therefore, they knew immediately it was not one of the three finch species native to the place.
"We didn't see him fly in from over the sea, but we noticed him shortly after he arrived". It was clear that the bird wasn't from Daphne Major, but its origins were unknown, so the scientists caught and tested the bird's blood before releasing him.
The large cactus finch bred with the native medium ground finch (Geospiza fortis).More news: Sony Xperia XZ and XZs now being updated to Android 8.0 Oreo
It turned out the intruder was from a species resident on Espanola Island, more than 100 kilometres away.
Scientists from Uppsala University analysed DNA collected from the parent birds and their offspring over the years.
However, he said if a group of individuals can keep mating among its own and keep a "competitive advantage" then the species will "keep on going". According to the new analysis, a new species was formed within just two generations.
This image is of a member of the Big Bird lineage. The baby finches were neither one nor the other, and developed with beaks and calls that were unmatched among the resident species.
The assumption that it takes hundreds of generations to create a new species is now debatable, as the ongoing study of the Big Birds has revealed that it takes as little as three generations for an entirely new species to develop.
"The surprise was that we would expect the hybrid would start to breed with one of the other species on the island and be absorbed", Andersson told the BBC.
"We have no indication about the long-term survival of the Big Bird lineage, but it has the potential to become a success, and it provides a handsome example of one way in which speciation occurs".