Human Errors: A Panorama of Our Glitches, from Pointless Bones to Broken Genes

by Nathan H. Lents

Evolution is a constant game of tradeoffs. Most innovations come with a cost.

Many birds can also see a broader range of wavelengths than we can, including ultraviolet light. In fact, migrating birds detect the North and South Poles with their eyes. Some birds literally see the Earth’s magnetic field.

Humans have more dietary requirements than almost any other animal in the world. Our bodies fail to make many of the things that other animals’ do.

Bacteria make B12 in the large intestine, the colon, but we can’t absorb it from there. We absorb B12 in the small intestine, which comes before the large intestine in the flow of traffic within the digestive system. So the wonderful bacteria of the human gut are nice enough to provide B12 for us, but the gut is so poorly designed that we send all of that B12 to the toilet.

To understand how this could be, let’s adopt a new analogy. Let’s call genes words, a string of letters of DNA that add up to something meaningful. In the “book” that is your genome, the spaces between these words are filled with incredibly long stretches of gibberish. All told, only 3 percent of the letters in your DNA are part of words; most of the remaining 97 percent is gobbledygook.

You expend a few dietary calories every single day just to copy your largely useless DNA.

Mothers dying in childbirth is unheard of in chimpanzees, bonobos, gorillas, and all of our other primate cousins. This is a purely human peril.

tail. Because the egg moves slowly and the sperm move quickly, conception almost always occurs in the fallopian tube; an ovulated egg is still meandering through the tube when a sperm cell rushes to meet it. (In fact, if it hasn’t been fertilized, an egg will usually perish before reaching the uterus—that’s how slow it’s moving.)

There is basically a 100 percent chance that, if you live long enough, you will get cancer. It will catch up with you eventually, provided you don’t die of something else.

We also have an anchoring bias. People give a great deal of value to the first piece of information they receive, regardless of its trustworthiness. This leads all further information to be valued not in strict terms but relative to the original.