The Oldest Sperm on Earth

Imagine that: 20 million year old sperm! You think you’re good…how’s that for longevity? They may be petrified, but hey, they made it all the way to modern times.

The fossilized fighters were found in an ancient cave in Australia and recently reported (read the Los Angeles Times take here) as the oldest ever found on this good earth. And guess what preserved them? Bat poop!

Miocene Meisters

No they weren’t human sperm. They were from much smaller creatures, called seed shrimp. But don’t laugh, because these sperm are huge! Our sperm are about 2/3 of a millimeter long, but these guys were 16 times bigger, almost half an inch long. Gees, gotta love the dinosaur age, when sperm were real sperm

Stacking Up

But that was then and now is now. How robust are human sperm? Well, it varies depending on where you find them. Within a women’s reproductive tract, it is thought that they live about 3 days. Cosseted within the male, they can probably live 3 months before venturing out into the world. Leave them on a dry, exposed surface of your choice, and they die as soon as things dry out.

How long does it take to make a human sperm? I got that one. About a decade ago, we published a study to figure this out. We had healthy men drink “heavy” (deuterated) water and ejaculate biweekly. The point was to see when the sperm DNA contained the ingested heavy water. We found that the average time to make and ejaculate sperm was 64 days, pretty quick. This also explains why fertility treatments for men take time, about 2-3 months, to work. Remember, Rome wasn’t built in a day and good things take time. Also be reminded that with sperm, great things can happen in the blink of an eye.

As I see it, the only real problem with being a petrified sperm is that clearly you weren’t the chosen one that became something else.

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Dr. Paul Turek, Medical Contributor

View posts by Dr. Paul Turek, Medical Contributor
Dr. Paul Turek is an internationally known thought leader in men’s reproductive and sexual health care and research. A fellowship trained, board-certified physician by the American Board of Urology (ABU), he has received numerous honors and awards for his work and is an active member in professional associations worldwide. His recent lectures, publications and book titles can be found in his curriculum vitae.
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