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Shrinking sheep 'defy' natural selection

作者:幸爻    发布时间:2019-03-08 08:07:00    

SHEEP living on a remote island off the coast of Scotland have been shrinking for 20 years. Shorter winters caused by climate change may be responsible. Soay sheep are a primitive breed of domestic sheep living free on the island of Hirta in the St Kilda archipelago. Over the last two decades, the average size of the sheep has been falling, but it was unclear why – particularly as natural selection would tend to promote the development of bigger bodies to help them survive the tough winters. To explore further,

 

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