Pixabay的Okan Caliskan的图像

The blast and fire that resulted from the Chernobyl Nuclear disaster in April 1986 in Ukraine was the most disastrous the world has encountered. The radioactive fallout released from this event was around 400 times more than that released by the nuclear bomb that struck Hiroshima in Japan. Furthermore, in addition to the radiation, major amounts of highly toxic heavy metals and both inorganic and organic compounds such as pesticides也被释放。Besides the immediate loss of life, it is thought that the final death attributed to this event will be many thousands as the long-term effects on health and mortality are realised. In total some 200,000 people were relocated as a consequence of the incident. Some 150,000 square kilometres are contaminated and an area of 30 miles around the reactor site is called the ‘Exclusion Zone’. One hundred and eighty seven small communities in the exclusion zone remain abandoned to this day. The long term impact on the immediate and wider environment is almost incalculable as all forms of plant and animal life struggle to survivesuch challenging and continuous exposures。

放射性辐射的乌云范围很广泛，甚至在威尔士的大约2,000英里远的地方造成了重大后果，在10,000个农场和400万绵羊地区，政府施加了限制。对于威尔士的某些人来说，这仍然是一个问题。37年后，在乌克兰这场灾难的中心上，某些地区仍然存在增加的放射性水平。放射性影响对植物生命和野生生物的影响一直是科学研究和基因突变率及其物理特征的影响的来源。不幸的是，该地区目前的敌对行动可能影响了这些重要研究的进步。

A recent article publishedinCanine Medicine and Genetics关于放射性辐射和其他环境危害的多代影响的报道，例如铅，农药和挥发性有机化合物对灾难后留下的狗的报道。鉴于一只家犬的平均寿命，从那以后，几代人都会翻倒，从那以后将出生许多垃圾。The authors apply their sophisticated molecular tools and analyses to gain some insight as to whether two discrete populations of free-breeding dogs living around Chernobyl today and believed to have descended from the ‘original’ domestic pets exhibit genetic features compatible with an adaption for increased survival. These two populations are found in the Chernobyl Exclusion Zone (CEZ) – one at the site of the nuclear power plant and the other in Chernobyl city, 16 kilometres away.

The high levels of toxic exposure, including radiation in this area are potentially impacting biological life in two ways. First, it might be prematurely shortening life expectancy of some animals through increased rates of cancers and radiation associated conditions. Second, it might be increasing mutation rates in the germline of gametes passed on to subsequent generations during reproduction. Furthermore, any predatory animals at the top of the food chain will increase their exposure to toxic substances and radiation through the food they consume.

研究中的两个不同种群彼此之间表现出显着的遗传多样性。考虑到它们之间的16公里距离，这本身就是有趣的，也许是出乎意料的。观察到的差异可能是由更大的农村地区的“创始人”人口对工作或护卫狗品种的代表性更大，而市区的其他“创始人”人口由较小的“家庭友好”品种组成。

这项研究的一个非常有趣的发现是，狗基因组中的某些基因表现出明确的方向选择证据，如果查尔斯·达尔文今天还活着，查尔斯·达尔文很乐意阅读。在研究中，作者发现了与方向选择影响的基因组区域相关的391个离群基因基因群，他们从中鉴定出了52个候选基因，这些基因从其生物学功能中有望在生存中很重要。

当施加新的外部压力时，当其平均分布在其人群中的平均分布的一侧比另一侧的人的平均分布在其人群中的一侧生存更好时，就会发生定向选择。换句话说，这是一种将人口中特征分布的平均值转移到新环境中生存的优化的机制。

This is a fundamental concept in evolutionary biology and is one of the underlying principles that Charles Darwin considered to be driving adaptive evolution. Given the toxic and highly radioactive conditions within the CEZ it is highly plausible to attribute this to the last 37 years of exposure to a strongly hostile environment.

Studies as this one demonstrate the power of interdisciplinary collaboration between international scientists which cross international boundaries for the benefit of all. So many other important questions could be addressed by investigating the impact of human desertion of previously occupied land. In a world where environmental change in all its forms is increasing, this knowledge is important.