Researchers have revealed that each one of us receives approximately 60 new mutations in our genome from our parents.
Using whole genome sequences from the 1000 Genomes Project, the researchers also showed that although most of our variety comes from reshuffling of genes from our parents, new mutations are the ultimate source from which new variation is drawn.
"We human geneticists have theorised that mutation rates might be different between the sexes or between people," said Dr Matt Hurles, Senior Group Leader at the Wellcome Trust Sanger Institute.
"We know now that, in some families, most mutations might arise from the mother, in others most will arise from the father. This is a surprise: many people expected that in all families most mutations would come from the father, due to the additional number of times that the genome needs to be copied to make a sperm, as opposed to an egg," he added.
The researchers studied two families consisting of both parents and one child, looking for new mutations present in the DNA from the children that were absent from their parents' genomes. They looked at almost 6000 possible mutations in the genome sequences.
After sorting the mutations into those that occurred during the production of sperm or eggs of the parents and those that may have occurred during the life of the child, they noticed that in one family 92 pc of the mutations were derived from the father.
However, only 36 pc mutations were derived from the father in the second family.
The results also revealed that human genomes, like all genomes are changed by the forces of mutation.