Their results, published in Environmental Pollution, show that as radiation levels in an arearose to 35 microsieverts per hour, the average number of birds dropped by almost a thirdcompared with the areas where radiation levels were only 0.5 microsieverts per hour. Thismakes sense: in those areas with a high level of radiation, living things would tend to die orsicken and fail to reproduce. However, when researchers looked at the 14 bird species thatlived in both regions, they found that the same level of radiation was associated with twiceas large a drop in bird numbers in Fukushima as in Chernobyl.
研究结果发表在《环境污染》杂志上:在辐射水平为35毫西弗/小时的地方,鸟类平均数量比0.5毫西弗 /小时的地方少了将近1/3。这是合情合理的:辐射水平高的地方,生物更容易生病死亡,更难繁衍后代。但是,当研究者比对两地共有的14种鸟类时,发现在同样的辐射水平下,福岛的鸟类下降数量几乎达到了切尔诺贝利的两倍。
The reasons for this are not clear. It is possible that the composition of the radionuclides areproving more dangerous to the Fukushima birds than they are to the birds near Chernobyl.But Dr Mousseau suggests a more likely explanation is that evolution has already been atwork near Chernobyl, killing off individual birds that cannot cope with the backgroundradiation and allowing the genes of those that have some tolerance to be passed on. Thebirds at Fukushima are only beginning to face the evolutionary challenge of living in aradioactive world.
【2015考研英语阅读英核辐射与进化】相关文章:
最新
2016-10-18
2016-10-11
2016-10-11
2016-10-08
2016-09-30
2016-09-30