2014年7月24日 Nature

nero1981

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- D4 R9 s2 u4 X: |2014年7月24日 Nature
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+ A& |; ]8 J. F# wAntarctic fur seals (Arctocephalus gazella) on an iceberg at Bird Island, South Georgia. This species was hunted almost to extinction by the early twentieth century but numbers began to recover when sealing operations stopped, and thanks to an abundant food supply it has survived in large numbers. But fur seals are particularly [url=http://staging-www.nature.com/nature/journal/v511/n7510/full/511414a.html]vulnerable to climate change[/url] as they inhabit a region with fast-changing temperatures, and their relatively long generation time limits their ability to adapt evolutionarily. [url=http://staging-www.nature.com/nature/journal/v511/n7510/full/nature13542.html]An analysis of three decades of data from South Georgia[/url] now shows that the seals are in decline again, with female numbers down by some 30% between 2003 and 2012. Harsh conditions have, however, selected for higher genetic heterozygosity among females. While this is not in itself an evolutionary response, as environmental conditions continue to worsen, heterozygote advantage could help maintain genetic variation, potentially buying time to allow the species to respond via adaptation. Cover photo: Jaume Forcada8 W0 W% o+ \4 ~+ k. a0 @

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yzzb003

东西是好东西，不知能下吗

geniusfzq

不错收下了4 k, p; \; ^9 W- Z

yuheng

xiexie

lamhy8

thank you so much

jingjing

kankan
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bobobuwa

谢谢分享

xiaojiang9945

但愿没来晚

千细胞

辛苦

Hunterofbetter

需要，感谢分享