A direct measure of the mutation rate in two family trios (mother, father and child), one from Utah and the other from SW Nigeria, finds that the average mutation rate is of the order of one mutation per 100 million sites, what totals some 60 inherited mutations per newborn child.
There was some remarkable variation between the number of mutations inherited from each parent but the data failed to support the hypothesis that the male line was more prone to introduce mutations just because one more meiosis takes place in the production of sperm than in the formation of ovules.
Ref. Donald F. Conrad et al. Variation in genome-wide mutation rates within and between human families. Nature 2011. Pay per view.
This is not the first case that real measures of the mutation rate happen to be slower that hypothesized:
- (L) Molecular clock: two to six times slower than thought.
- (L) Mutation rate is less than half.
- Very low mutation rate, mwahahaha!
And let's not forget that we diverged from Chimps not before 8 million years ago. But way too many geneticists and other people who write on genetics ignore these facts of life, what I find pretty much unscientific (careless at best, mischievous at worst).