There are 13 species of small birds commonly known as Darwin's finches, found only on the Galápagos Islands in the Pacific Ocean, 1000 km west of South America. Their closest living relative is the dull-coloured grassquit, Asemospiza obscura, which is found on mainland South America. It is believed that Darwin's finches evolved from A. obscura or from its ancestor on the mainland. The different finch species are similar in colour but vary in beak size and shape, habitat and diet. Discuss how the different species of Darwin's finches arose from an ancestral population on the mainland. In your response, name the type of speciation that occurred and identify the main selection pressure(s) that has acted on finch populations. (6 marks) --- 12 WORK AREA LINES (style=lined) ---
BIOLOGY, M3 EQ-Bank 23
Explain how the finches on the Galapagos Islands support Darwin's theory of Natural Selection. (5 marks)
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