Researchers estimate that human mutations are occurring a third slower than previously calculated.
On average, 30 mutations are transmitted from parent to child, which revises prior estimations and changes the timescale that is used to determine the number of generations separating humans from other species.
“Three billion [nucleotides] come from each parent, and based on indirect evolutionary studies, we had previously estimated that parents would contribute an average of 100-200 mistakes in these pieces of information to their child. Our genetic study, the first of its kind, shows that actually much fewer mistakes – or mutations – are made,” Philip Awadalla, stated in a press release.
The researchers examined the genomes of two families – a mother, father and their child – which lead to their initial discovery and to examine the theory that men contribute more mutations to their children than women. This stems from the idea that more mistakes occur during cell division and DNA replication, and males produce millions more gametes than women. Variation between families showed that mutations vary “from individual to individual or even that some people have mechanisms that reduce the likelihood of mutations,” Awadalla stated.
Further research with more families could help tie specific genetic mutations to diseases.