The researchers dosed Caenhorabditis elegans worms with Levamisole, a widely-used pesticide which acts on the nervous system. True to form, the toxin worked quickly, reducing the fertility and survival rates of male worms. However the population survived because the worms are hermaphroditic and some members contain both male and female sexual organs, and adapted to the presence of the pesticide.
By the 10th generation fertility had recovered and by the 20th generation numbers had increased once more.
This article first appeared in the Ecologist December 2008
