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Chernobyl radiation changes way worms reproduce WORMS caught in the radioactive fallout from Chernobyl have found a new sexual preference – for each other, rather than themselves. According
to scientists, they may have changed their behaviour toincrease
their chances of survival. The sexual switch is said to be one of
the first direct examples of the way wildlife is influenced by radioactive Scientists made the discovery while studying the long-term impact of the nuclear plant explosion at Chernobyl, Ukraine, 17 years ago. Researchers Gennady Polikarpov and Victoria Tsytsugina, from the Institute of Biology of the Southern Seas in Sevastopol, compared the behaviour of aquatic worms living in two lakes. The lakes, one near Chernobyl and the other 20km away, had similar temperatures and chemical composition. But worms in the Chernobyl lake had received 20 times as much radiation as those in the other lake. The researchers found that two species of Chernobyl worms had changed from asexual to sexual reproduction. Instead of behaving as hermaphrodites and having sex on their own, they started seeking partners. In the unaffected lake, just 5% of the species Nais pardalis reproduced sexually – but in the Chernobyl lake 22% cent sought sex with each other. The proportions of the species Nais pseudobtusa doing the same were 10% and 23% respectively. However, a third species, Dero obtusa, showed double the rate of asexual reproduction in the polluted lake. New Scientist said: “Polikarpov thinks the worms have switched to sexual reproduction to protect themselves from the radiation. Sexual reproduction allows natural selection to promote genes that offer better protection from radiation damage.” Carmel Mothersill, from the Dublin Institute of Technology, which is helping experts develop new radiation safety limits to protect wildlife, said: “It is a plausible mechanism.” – dpa
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pollution.