Commenting on the find, snake expert Robert Henderson, from the Milwaukee Museum of Natural History, said, "Worldwide, new species of frogs are being discovered and described quite regularly."

密尔沃基自然历史博物馆的蛇类专家罗伯特·亨德森对这个发现评价称：“在世界范围内，人们经常会发现和描述新种类的青蛙。”

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Thanks to natural selection, most species that have ever lived has already gone extinct, so this is not a new phenomenon.

由于自然选择，大多数曾经存在过的物种已经灭绝，所以这不是一个新现象。

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Snake expert Robert Henderson, from the Milwaukee Museum of Natural History, said, "Worldwide, new species of frogs are being discovered and described quite regularly."

密尔沃基自然历史博物馆的蛇类专家罗伯特·亨德森说：“在世界范围内，人们经常发现和描述新的青蛙种类。”

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These pictures show young readers what led Darwin to form his great discovery: the evolution of species through natural selection.

VOA: special.2009.02.27

And in fact, Skinner explicitly made the analogy from the natural selection of species to the natural selection of behavior.

实际上，斯金纳也确实明确地,对物种的自然选择,同行为的自然选择进行过类比。

耶鲁公开课 - 心理学导论课程节选

Natural selection does not explain everything about why species evolve.

VOA: special.2009.02.25

This requires working with farmers to conserve natural ecosystems and species as well as protect water resources.

FORBES: For Nestl��, Sustainability is a Journey

And although the parakeets required human assistance to get from Asia to Britain, their arrival is only an extreme form of the constant, natural shuffling of species brought about by the movements of adventurous individuals which studies such as this seek to monitor.

ECONOMIST: The oldest bird in the world

With few natural predators, they are now listed as a "pest species" by Natural England.

BBC: Windermere's 'polluting' Canada geese to be culled