An island of the Galapagos archipelago is home to a brand new species, which provides direct evidence that a species can develop from two other species in as little as two generations. The Galapagos Islands, in the Pacific Ocean, are such a remote area that it is the ideal place to study evolution, biodiversity and natural selection. The current research was an analysis of decades of field work on Darwin’s finches, inhabitants of this remote ecosystem.
Two Princeton scientists, B. Rosemary Grant and Peter Grant, conducted field work on the archipelago over the last four decades. As a result of this field work, researchers were able to directly observe the origin of a brand new bird species, a report in the journal Science indicates.
“The novelty of this study is that we can follow the emergence of new species in the wild,” B. Rosemary Grant explained. “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.”
Almost 40 years ago, a graduate student working with the researchers noticed a male bird that was much larger in body and beak size than the species that were known natives on Daphne Major. The bird also sang a peculiar song, differing from the other native birds. The team gathered a blood sample. According to Science Daily, the male bird was a large cactus finch. His species is known as Geospiza conirostris. His species was from Española island.
Because he had no birds of his species to mate with on Daphne Major, he chose a mate from one of the native species. The large bird bred with a medium ground finch of the Geospiza fortis species. The team took more blood samples as they followed the lineage for six generations. The offspring ended up mating within their own lineage, because their songs were so unique and songs are used to attract mates.
The new research examined the blood tests and genetics that were compiled during the field research over the last four decades. According to the new analysis, a new species was formed within just two generations.
“It is very striking that when we compare the size and shape of the Big Bird beaks with the beak morphologies of the other three species inhabiting Daphne Major, the Big Birds occupy their own niche in the beak morphology space,” Harvard’s Sangeet Lamichhaney, first author on the study, said. “Thus, the combination of gene variants contributed from the two interbreeding species in combination with natural selection led to the evolution of a beak morphology that was competitive and unique.”
So, while it was previously believed that it would take hundreds of generations to bring about a new species, this example shows that it can happen just two generations after two separate species breed in nature. It is, of course, easier to achieve the origin of a new species in a small island-like setting like Daphne Major in the Galapagos Islands.
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