How does one species become many?
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Evolutionary biologists have long suspected that the diversification of a single species into multiple descendent species 鈥 that is, an 鈥渁daptive radiation鈥 鈥 is the result of each species adapting to a different environment. Yet formal tests of this hypothesis have been elusive owing to the difficulty of firmly establishing the relationship between species traits and evolutionary 鈥渇itness鈥 for a group of related species that recently diverged from a common ancestral species.
A global team of biologists led by 不良研究所 have compiled nearly two decades of field data 鈥 representing the study of more than 3,400 Darwin鈥檚 finches in the Gal谩pagos Islands 鈥 to identify the relationship between beak traits and the longevity of individual finches from four different species.