Evolution is a process which usually has to be measured over thousands, if not millions of years, but that is not the case with the Big Bird finch. Scientists have been able to see this new species emerge within two generations as the result of a hybridisation of two separate species. This is recordable, observable evolution seen within our lifetime.
A recent paper published in Science documents researchers’ findings on the development of this new species. The fact that this new species emerged as the result of two separate species creating a hybrid is reportedly changing some scientists’ assumptions about how significant hybrids are in the evolutionary process.
It is not without irony that the Big Bird finch developed from among the 15 species of finch known as Darwin’s finches, which inhabit the Galapagos islands. Darwin saw the diversity among the Galapagos finches, which helped to develop his theories concerning natural selection and evolution. The new species derives its name, in spite of the presumed lack of a Sesame Street on the Galapagos islands, simply due its large size relative to the other finches in the vicinity.
The new species reportedly emerged around 1981 when a large cactus finch, over 100km away from its original home, mated with a medium ground finch on the Galapagos island of Daphne Major. This created an entire lineage of new birds, belonging to neither species, but the start of a new one.
Peter R. Grant and B. Rosemary Grant, biologists from Princeton University have been observing the species’ development since they first recorded the original Big Bird’s presence on Daphne Major in 1981. The species apparently dwindled to two individuals around 2002, though it rallied and reproduced, creating a larger if highly inbred population once more over time. The large size of individuals from the new species gave them an advantage in finding food and, presumably in other forms of competition and, in 2012, 23 individuals and 8 breeding pairs were recorded on the island.
The development of the Big Bird finch is a fascinating insight into the complex and surprising nature of the evolutionary process, providing shocking new answers and many new questions about the ever growing, adapting, developing world around us.