They have not had sex for 30 million years and, against all odds, managed to survive. The bdelloid rotifers are a microscopic aquatic animals that live in ponds, rivers and wetlands as soils, mosses and lichens.
These little creatures multiply by producing eggs that are genetic clones of the mother, since there are no males. Scientists have always wondered how they have endured so much and have managed to escape the “curse” of the Red Queen , a theory that says that asexual lineages eventually become extinct because of parasites and pathogens. Now they know how.
As reported in the journal Science , scientists at Cornell University have discovered the secret of the extraordinary longevity of this lineage. “These animals have evolved a way to avoid parasites and pathogens by drying and wind,” says Paul Sherman, professor of neurobiology. Regard discover a dangerous pathogen, like a deadly fungus, these invertebrates are dried completely. Was again so arid that parasites can not survive and, after transforming, rotifers are going with the wind to another safer area, sometimes located hundreds of miles away, where they return to wet like a sponge, free of enemies. There can establish new uninfected populations.
This strategy has enabled these tiny animals are not only survive, but thrive in over 450 species. Scientists believe that this finding “will help to answer on one of the deepest mysteries of evolutionary biology: Why sex is almost omnipresent? ».