New research into the effects of a chemical pesticide contamination has shown that the chemical is persistent not only in the environment, but remains as a agent of mutation and change through several generations
Study of the water fleas, called Daphnia, have shown that the second generation offsprings had chemically induced mutations that transferred to the third generation. First of all the chemical exposure to pesticides caused a skew in the gender of births in the second generation, but then continued to affect the births of the third generation.
The determinant factor in the gender population is usually the environment and the clues it holds. But the pesticide chemical seems to disrupt the ability of the insect to read those clues.
Scientists had identified a hormone in Daphnia, called methyl farnesoate, that the insect produces under certain enviromental stresses. The production of this hormone skews the numbers of spawns to the male gender. This in general reduces the insect's ability to reproduce in normal numbers.
That is because an insecticide, called pyriproxyfen, mimics the hormone's receptor protein which affects the gender of the second generation births.
The study was confirmed by changing the concentration of the pesticide. In fact the higher the concentration, the higher the number of male offspring produced by Daphnia. But the study showed that even at low concentrations, the effects were significant. And the females born in second generation, produced smaller numbers of offspring, even though they were removed from the contaminated environment after birth.
Although many might question the relevance of the small insect, Daphnia is a very important link in the food chain, especially for fish spawns and other smaller aquatic life.
Source : Science Daily 4.23.13
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