According to Wikipedia, evolution is defined as a "slow change in groups of living things over time". One of the tenets of evolutionary theory is that people should actually die of old age once their reproductive lives are complete, at around age 55. It has, however, been speculated by scientists that the ability of some men to reproduce well past that age may actually be of benefit to our species. This is because natural selection fights off life shortening mutations until we are finished reproducing. The benefits of grandparenting aside, we are left to wonder if this is good news or bad for men who wish to become dads later on in life.
According to Dr. Harry Fisch, New York based urologist and author of the book "The Male Biological Clock", "Male fertility declines with aging. Among women 35 and older, those whose male partners were 45 and beyond took five times longer to conceive than those whose partners were 25 or younger".
Clearly, the phenomena of the male biological clock is real.
Dr. Fisch goes on to state that "women eventually reach menopause (and can no longer reproduce), but men manufacture sperm throughout their lifetime. That is why you often see men fathering children at an older age."
Is this evolution at work? And more importantly, what does this mean to you, if you are considering your own family building plans? Despite the fact that many men will have the physical ability to father children into later life, is it a good idea for you?
Multiple studies have shown decreased IQ rates, as well as significantly increased levels of autism, schizophrenia, birth defects and bi polar disorder among children whose fathers were over the age of 40 at the time of conception, with the most significant changes being documented in the offspring of men who fathered them over the age of 55. It is currently theorized that sperm mutations are the culprits causing these conditions to occur. While this by no means indicates that all children of older fathers will be so inflicted, statistically up to 37% of many documented cases of bi polar disorder and developmental delays may be attributed to advanced paternal age, at least in part.
With improved health care and good nutrition we as a society are getting younger all the time, and that's very good news. However, men of advanced age should consider a sit down with a reproductive specialist prior to becoming dads, whether they are considering fatherhood for the first time or the tenth. Discuss your genetic history with your physician, particularly if schizophrenia or bipolar disorder is part of your family tree. Weigh the pros and cons as they pertain to your individual situation, so that you can go forward and feel comfortable in your own personal family building decisions.