The findings may also help explain one of the mysteries of genetics: why scientists have yet to account for much of the genetic component of common diseases. Common diseases tend to be caused by the interaction of many genes, but despite powerful genome-wide association scans to search for these genes, relatively few have been uncovered. Several of these diseases, including breast cancer, autism and schizophrenia, seem to be more frequent in the offspring of older fathers, but the reasons are unknown. Professor Wilkie suggests that similar - but milder - mutations might contribute to these diseases.

"What we have seen so far may just be the tip of a large iceberg of mildly harmful mutations being introduced into our genome," he explains. "These mutations would be too weak and too rare to be picked up by our current technology, but their sheer number would have a cumulative effect, leading to disease."

Further research is needed to find other genes that are affected by this process. However, DNA sequencing technology has recently undergone a step change in capacity, enabling more sequence to be obtained in one day than was possible in a whole year just a decade ago. As the sequencing data emerge over the next decade, we should discover just how vulnerable we are to men's selfish mutation factories.

Source: Wellcome Trust