What is the male biological clock?

People always assume that men don't have a biological clock because we know that Charlie Chaplin and plenty of famous people have had children way into later life, but actually, it's much more subtle with men. We now know that there is indeed a biological clock in men. We never really understood this before. There are two elements to this. First of all, there's a subtle one and that is when a man ages, he may well be able to have sperm that fertilise an egg and produce children, but those children are affected. His DNA has actually aged as he's aged and the risks then are in the children. There is scientific evidence to suggest that there's an increase in autism, an increase in epilepsy, an increase in leukaemia, as examples, in children who are born to men of much later age. We also now have found out that indeed men also cause miscarriage in women if they're older. The incidence of miscarriage is higher and apparently fertilisation can be much lower, too. It could actually affect their fertility. Men do have a biological clock. It's not been well understood until probably the last five years. It's becoming an increasing problem. In fact, the whole biological clock issue is a great issue, a great concern for our society because we have declining birth rates and couples not having children until much later in life. It's a compounding problem.