The reason why the find is important to science is because this represents the first empirical observance of an animal undergoing speciation. The find has come about after biologists have been painstakingly tracking the entire population of finches located on the small Galápagos island of Daphne Major over the course of several years.
It was on the Galápagos archipelago, during the nineteenth century, that Charles Darwin came up with parallel findings to Allred Russel Wallace on what was then a theory of evolution – at the time controversial, before becoming an accepted scientific fact into the twentieth century.
Starting from 1981, the biologists charted the arrival of a male of a non-native species onto the island. This was the large cactus finch (Geospiza conirostris); the male is black, with white-tipped undertail coverts. The male then began to mate with females of a species long associated with the island – the medium ground finch (Geospiza fortis); the female’s plumage is brown and streaky. The large cactus finch male is thought to have come from the large cactus finches’ home island of Española, around 65 miles away.
Over the course of forty years, biologists Professor Rosemary and Professor Peter Grant tracked the progeny of the original coupling through the mating and birth cycles. Over time, a new species, through the process of natural selection, has been cataloged as emerging.
Speaking with BBC Science, an independent scientist called Professor Roger Butlin said: “It’s an extreme case of something we’re coming to realize more generally over the years. Evolution in general can happen very quickly.”
In terms of what constitutes a new species, the new finch is different from the native birds in terms of appearance and habits. What is atypical is the speed at which this has happened; hitherto, observed offspring of cross-species matings have been noised as poorly adapted to their environment.
At present, the new finches are referred to as the ‘Big Bird population’. An official species name will be given after the international speciation recognition process has been completed Native females will not mate with males of the new species due to an inability to recognize the songs of the new males. This has been confirmed by genetic testing, which shows that after two generations elapsed there was reproductive isolation from the native finches.
The scientific implication is that the biological process of hybridization can lead to speciation in the same way that mutation, the more established basis of evolution, can. Hybridization is the process of combining different varieties of organisms to create a hybrid.
The new research has been published in the journal Science. The research is titled “Rapid hybrid speciation in Darwin’s finches.”
Essential Science
This article is part of Digital Journal’s regular Essential Science columns. Each week Tim Sandle explores a topical and important scientific issue. Last week we presented research designed to improve detectability of malaria. Here researchers have developed a new test for the causative parasite. The test uses the latest nanoscience technology.
The week before we helped to break the news about the first ever gene treatment of a child to address terrible skin damage. This pioneering technoque has been undertaken using transplants developed from genetically modified stem cells. The treatment was a novel form of gene therapy.
