Nature published the results today. As a man ages past 40 for every year past, his sperm develops two additional mutations per year.

The study’s senior author – a scientist in Iceland – writes: “Conventional wisdom has been to blame the developmental disorders of children on the age of mothers”… but “it is the age of fathers that appears to be the real culprit.”

The latest numbers from the Centers for Disease Control indicate the rate of autism has doubled in the last six years from 1 in 162, to 1 in 88.

The number of men 40 and older who father a child has increased by more than 30 percent since 1980.

For the first time we have hard numbers that explain the data which could answer to the mysterious rise in the rates of autism.

“This study shows that new mutations are frequent enough as men age that fathers aging alone can explain the increase for the risk of autism,” said Dr. Delores Maldespina, a psychiatrist at New York University.