The biological clock, like all other physiological functions, is also shared between man and woman, says a new study on the topic. But the surprising news is that not just the fairer sex, even the alpha male suffers a drop in fertility levels after reaching late thirties or early forties.
The study found that male fertility begins to decline when they reach their mid-30s, suggesting that biological clocks are found in men as well as women.
According to the scientists, men who wait until their 40s before starting a family, have a greater chance of their partner having a miscarriage, owing to the poorer quality of their sperm.
A Sydney IVF clinic carried out the research on 3,324 men over a four-year period.
"Drops in fertility from the age of 35 have been traditionally thought of as a fact-of-life for women but our study shows the same is true for men," the Telegraph quoted Dr Mark Bowman, the director of the IVF clinic, as saying.
The researchers tested their sperm DNA to assess its "reproductive potential", and found that starting from 35 years of age; there was a significant increase in the proportion of damaged sperm.
Bowman added: "This means that even if a man produces the average of 40 million sperm per ejaculation, many of those sperm will not be able to fertilize an egg normally. He will have a lower fertility potential and be less likely to father a child."
The study provides further evidence that men have a biological clock.