a),b),d),e) are the correct steps which lead to speciation and a diverse range of finch types
Darwin's finches, inhabiting the Galapagos island constitute an iconic model for studies of speciation and adaptive evolution
Darwin's finches have evolved into 13 recognized species differing in body size, beak shape, song and feeding behavior
Changes in the size and form of the beak have enabled different species to utilize different food resources such us insects, seeds, nectar from cactus flowers as well as blood from iguanas, all driven by Darwinian selection
Gene flow between species has played a prominent role throughout the evolutionary history of Darwin's finches
Interspecies hybridization has played a critical role in the evolution of the finches, and has contributed to maintaining their genetic diversity
The ecological niches exert the selection pressures that push the populations in various directions
On various islands, finch species have become adapted for different diets: seeds, insects, flowers, the blood of seabirds, and leaves
The ancestral finch was a ground-dwelling, seed-eating finch and after the outbreak of speciation in the Galapagos, a total of 13 species would exist
