2005 was also a standout year for researchers studying the emergence of new species, or speciation.

2005年也是研究新物种出现，或称物种形成，的科学家们作出杰出工作的一年。

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The actual moment when a "daughter" species can (or will) no longer cross-breed with the population from which it sprang (the definition of speciation) is almost impossible to pinpoint, let alone to witness.

WSJ: Matt Ridley on the Possible Formation of a Species | Mind & Matter