“The human body though. 😍” If any line accurately represents the general attitude about the structure and appearance of the human body, that would be it (heart-eye emoji included, of course). Human history is laden with odes and praises about the anatomy of our species and how each piece of ourselves is immaculately put together. Many have even gone to say that the way our bodies are structured is evidence of intelligent design by a divine creator. Others use our biological makeup as evidence that we are indeed apex predators and the supreme of all species on Earth in just about every way. And these sentiments are not just expressed in our minds or in conversation with others. They are written in books.

“Human Errors” is not one of those books.

We have retinas that face backward, the stump of a tail, and way too many bones in our wrists. We must find vitamins and nutrients in our diets that other animals simply make for themselves. We are poorly equipped to survive in the climates in which we now live. We have nerves that take bizarre paths, muscles that attach to nothing, and lymph nodes that do more harm than good. Our genomes are filled with genes that don’t work, chromosomes that break, and viral carcasses from past infections. We have brains that play tricks on us, cognitive biases and prejudices, and a tendency to kill one another in large numbers. Millions of us can’t even reproduce successfully without a whole lot of help from modern science.

After giving us an information-filled introduction of our body’s blunders, Nathan Lents takes the reader along a journey in “Human Errors: A Panorama of Our Glitches, from Pointless Bones to Broken Genes.” In this book, he details specific errors in our body’s composition and how they fall short of perfection.

In this review, I will note those human errors that stuck out most to me, some constructive criticism, why I think this book should be next on your reading list, and where you can get this book for free.

Notable mentions and constructive criticisms of “Human Errors”

1. We have a nerve that is longer than it needs to be and is awkwardly placed for no useful reason.

The recurrent laryngeal nerve (RLN for short) is a nerve that helps control the muscles that allow us to talk, hum, and sing. It is found in the chest and neck region of our bodies, branching off of the vagus nerve on our left side, looping underneath the aortic arch, and traveling back up the neck from the larynx on our right (see image). Lents argues that the RLN is three times longer than it needs to be, threading through our chest and beneath our heart’s aorta, creating an obstacle for heart surgeons as they make sure not to cut it during operation lest our ability to talk be compromised. Lents drives home the point of the unnecessary length of our pharyngeal nerve by comparing ours to that of the fish. Lents notes that the route of the RLN in the fish is much more brief and predictable, making it a far more efficient path for the RLN compared to humans. He later notes that just as our RLN weaves around the aorta of our heart, the fish’s RLN also weaves through major branches in their heart. From an evolutionary perspective, Lents notes that this pattern of throat-to-heart looping stayed as the fish evolved to the tetrapods that would eventually give rise to humans. And this pattern stayed with us for no advantageous purpose.

2. Our eyesight is unimpressive compared to that of our animal friends.

For a species that is often lauds itself as the top of the food chain, Lents makes it clear that our eyesight must have missed the memo. Beyond the fact that 30% to 40% of Americans are nearsighted and a whopping 70% of Asian countries are as well, needing glasses to compensate for poor eyesight, our eyes continue to be unimpressive when looking at other members of the animal kingdom. Beyond the eagles’ and condors’ ability to see across great distances, Lents states that other birds can detect the North and South poles with their eyes. He goes on to say how some can even see ultraviolet wavelengths and migratory birds can see magnetic fields. He mentions the additional translucent eyelid that many birds have, allowing them to look into the sun without damaging their retinas. And here we are, apex predators, digging into our bags for our sunglasses and pulling down the sun visor in front of our faces as we sit in the front seat of our cars.

Cats also have superior eyesight to humans, having the ability to see a single photon of light in a dark room. In fact, most other animals do a better job of seeing in the dark than we do, including the dogs that cannot see color.

The most impactful representation of our ocular inadequacy is shown in this illustration on the left that compares the photoreceptors (or light receptors) in the eyes of a cephalopods (octopus, squid, etc.) with the light receptors in us vertebrates.  Lents argues that the backward bending of the photoreceptors in vertebrates makes for a poor means of making vision possible. After all, the end of the photoreceptor that actually takes in the light is facing away from where the light is coming in the eye. In cephalopods, they face forward. And we have not even mentioned the thin tissue and blood vessels the light has to pass through in the eye, thereby adding more barriers for light to enter the vertebrate eye.

3. Broken genes contribute to our inability to make certain nutrients.

“Humans have more dietary requirements than almost any other animal in the world.” That sentence was eye-opening, especially as someone who has lately become a nutrition nerd. While most organisms can synthesize Vitamin C, humans (along with other primates and other critters like guinea pigs and fruit bats) must get it from food. Lents argues that we contain the gene that synthesizes Vitamin C called GULO. The problem, however, is that it is broken, hence why it is often referred to as a pseudogene. Lents explains that early in prehistory, our ancestors carried this broken gene and, for some reason, we still carry it, the forces of evolution deciding not to fix this gene to our benefit. As a result, it is important that we get an adequate supply for Vitamin C in our diet or we may suffer from scurvy.

4. Most of our DNA seems useless.

Only 3% of our DNA actually codes for our genes. The 97% of the DNA leftover is deemed “junk DNA” since it does not code for anything in our genome. I appreciated that Lents mentioned that the term “junk DNA” has brought tension in the science community since some scientists have found various portions of the junk DNA to be purposeful despite being noncoding. Given this, Lents makes the distinction between the junk DNA or the noncoding bit of DNA and what he has termed “true junk DNA: the broken genes, viral byproducts, pointless copies, and worthless code that clutter our cells.” While I found this distinction insightful, I would have liked to know the percentage of true junk DNA and how it compares to the amount of junk DNA and DNA as a whole in humans. That would have given greater insight into how prevalent completely useless information truly is in our DNA.

5. Sperm cannot turn left.

With their tails winding round only in a clockwise corkscrew direction, as Lents explained, sperm take much longer than necessary to reach the egg; what could be a 45-minute journey can take up to three days. And even then, so few sperm actually make it to the egg despite so many of them being released. According to Lents, it takes 200 million sperm released for one of them to make it to the egg.

6. Childbirth for human mothers is unsafe compared to primates.

In the Homo sterilis chapter of “Human Errors,” Lents says the following:

“Childbirth is safer for primate mothers in the wild than it is for human mothers, and that’s without primates having the benefits of medical intervention. Mothers dying in childbirth is unheard of in chimpanzees, bonobos, gorillas, and all of our other primate cousins. This is a purely human peril.”

I found this to be a jaw-dropping observation. Continuing in the vein of primate advantages that humans don’t have, I would have loved to see Lents mention Plasmodium, the parasite genus responsible for malaria in humans. Chimpanzees are immune to Plasmodium falciparum, the parasite responsible for the deadliest form of malaria in humans. It claims a million human lives annually, mostly in sub-Saharan Africa and most of deaths being children under the age of 5.

Though I know that there is no way Lents could have mentioned every single biological issue in human bodies, mentioning instances in which primates and other animals are immune to certain illnesses that are deadly to humans (like in the case of malaria) would have driven the imperfection of the human body home even further.

Why You Should Read “Human Errors”

I would say that all of us suffer from some sort of selective amnesia when it comes to the discussions about our bodies, mostly focusing on the positive structures and compositions of it while seeing the errors primarily within the context of illness and disease. That has certainly been true for me. I recall a couple of occasions in which I saw viral videos of pregnant women and their fetuses moving around in their uteruses. I was amazed by it. But beneath the seemingly seamless ways our anatomy fits and functions together, we have anatomical hiccups that affect each and everyone of us all the way down to our genes. Reading books like “Human Errors” bring those mishaps to the forefront, tearing us away from the romanticization of our body’s abilities, and keeps us aware of our bodies functional flaws. So in the case of those pregnant women, while the accommodation of a growing fetus and its activity within a pregnant woman may be awe-inspiring, the fact remains that the impending birth is a lot less deadly in our primate cousins than in ourselves.

I think this book is also a worthy read for those who believe in a personal creator god. It gives them an opportunity to think thoughtfully or even critically about what it means to be intelligently designed. Taking the words from the infamous Psalm 139, there is a verse in which David lauds how he is fearfully and wonderfully made, a sentiment that Christians (Muslims and some Jews, too, though they follow different religions) espouse. It’s a beautiful sentiment to embrace, the idea that even before you were formed within your mother’s womb, God thought deeply about how you would be created. And during the act, he took his time, meticulously crafting you and molding you, laying the groundwork of your physical existence via your DNA and allowing his creative genius to shine through.

The following questions and more can be explored by reading this book:

Does intelligent design include efficiency in the design? If so, how does the RLN depict God’s intelligent design when it lacks that efficiency?

If we are so thoughtfully and purposely made, how is that communicated via the remnants of viral DNA, broken genes, and useless clutter that litters our genetic code?

Christians are probably familiar with the verse in Matthew in which Jesus is thought to have said, “Look at the birds of the air; they do not sow or reap or store away in barns, and yet your heavenly Father feeds them. Are you not much more valuable than they?” Given the value Jesus places on human life in comparison to birds, why are certain avian species blessed with such pristine visual acuity while humans, the more loved species, are not? Why are there primates with better birthing outcomes than humans, especially considering that the human species are the ones told by God to “be fruitful and multiply?”

Where to get a copy of “Human Errors.”

For the sake of full disclosure, as an Amazon Associate, I earn from qualifying purchases made from this post, but it’s at no extra cost to you. If you are interested in getting “Human Errors” for free, here’s are couple of options:

1. Sign up for Kindle Unlimited. Unlimited Reading. Unlimited Listening. Any Device. Try your first month free. Click here for the free trial and search for “Human Errors” in their selection of books.
2. Sign up for Audible’s free trial. You can get two free audiobooks and you get to keep them even after the free trial ends. Claim the offer here and search for “Human Errors” in the Audible library.

If you would prefer buying it, you can click here.

What aspect of the book did I mention that stuck out most to you? Is this a book that you would be interested in reading? Share your thoughts in the comments section below.