Men have traditionally assumed they’ve got all the time in the world to father wee ones. But they may have their own biological clock of sorts, according to new studies that show that older men’s children are more prone to genetic and behavioral disorders. Previous studies found that older men are more inclined to have kids with autism, Down syndrome and bipolar disorder. Now guys are learning that aging fathers are more likely to have children with autism or schizophrenia. The reason? Older dads transmit more random genetic mutations to their kids, and that ups their risk for disease.