“The testicle is the future.” – Harry Fisch

According to a few recent studies, human sperm has been decreasing in quality for over a century. Men are making less sperm on average; furthermore, the sperm that are produced swim poorly, are oddly shaped, come in low concentrations, and have a lower success rate of impregnating an egg. Low sperm counts are linked to factors of men’s health such as aging, being too fat or too thin, exercising too much or too little, poor diet, toxins in food and the air, and drugs including tobacco and alcohol. The urologist and researcher Harry Fisch of Weill Cornell Medical College believes that in most cases, improving a man’s health will solve his fertility problems. He encourages taking men off testosterone supplements, which can actually shrink the testicles and decrease sperm count.

Sperm stained to test semen quality. (from http://upload.wikimedia.org/wikipedia/commons/4/4e/Sperm_stained.JPG)

However, male fertility problems are also linked to our DNA. According to Sherman Silber, an urologist and researcher at the Infertility Center of St. Louis, the Y chromosome is “molecularly programmed to degrade over time.” This is because the Y chromosome, which codes for the cell machinery that makes sperm, cannot correct itself during cell division because it does not have a corresponding Y chromosome to serve as a template. This degradation occurs in other species as well, but is countered by polygamous mating and fighting between males for mates. Human society, on the other hand, encourages monogamy and non-mortal competition between men.

Even more alarming, a recent study by Gary Cherr, a reproductive toxologist, found that a quarter of human males have a mutated version of the gene that codes for the protective protein coat around sperm. The sperm may appear healthy, but in fact have a lower chance of being able to successfully impregnate an egg. Since this mutated form of the gene is present, it probably confers some advantage, similar to how the mutation that causes sickle cell anemia increases malaria resistance.

Sperm entering the egg. (from: http://upload.wikimedia.org/wikipedia/commons/8/86/Sperm-egg.jpg)

New developments in technology cope with this growing infertility problem. For men who lack the gene for the aforementioned protein coat, there could be a gel that imitates the protein coat that could be applied before sex. For men who do not produce sperm at all—one percent of American men—scientists are currently developing technology to harvest stem cells from the testicles and grow them into sperm-producing cells. In vitro fertilization (IVF) is another way to deal with fertilization problems; it has already been used to create four million people.

Of course, all this technology enables infertile men to procreate and propagate their infertile genes. In other words, people with low fertility are no longer selected against. Silber predicts that in 10,000 years, all men will be infertile.

- Samantha Masaki

Freedman, David. (2012). The sperm crisis: a tough nut to crack. Discover Magazine. Retrieved from: http://discovermagazine.com/2011/nov/12-impatient-futurist-sperm-crisis-tough-nut-crack.