Human Errors poses the quite beautiful hypothesis that it’s precisely because of our imperfections that we’ve strived so hard to overcome them and thus come so far as a species. Cancer, for example, is in one sense a necessary byproduct of the process that gives cells life to begin with.
Each chapter leads us through whistle stop tours of the common problems that seem like complete idiocy on the part of evolution; autoimmune diseases, the most widely varied diet in the animal kingdom thanks to all the chemicals we can’t synthesise ourselves, how comparatively difficult it is to conceive and carry a baby to term and behaviours that are outright stupid at times.
Some of the examples you probably don’t know border on hilarious, like the Achilles tendon, the most critical part of the locomotion system that’s also the most exposed and vulnerable. Or there’s the left recurrent laryngeal nerve that connects the brain to the larynx. In most animals it’d be a trip of only inches, but because of a quirk of evolution it loops under the aorta before returning back to the head (one we at least don’t have the silliest expression of – in the brachiosaur, it travelled almost 20 metres to connect two organs centimetres apart).
But Human Errors isn’t a comedy. If you read between the lines, Lents is expanding on the themes of the Selfish Gene. The forehead-slapping design flaws he’s talking about might give us discomfort or pain but if they don’t interfere with reproduction (although some seem to), nature doesn’t care if we’re happy as individuals. As Lents says ‘…that’s evolution for you. Crazy stuff happens. Most of it is bad – but when it’s good, it’s really good.’
It’s written with a lot of personality and is often laugh out loud funny, but the uniquely lovely message at it’s heart is that we’ve endured aeons of poor design, agony and death only to rise above it and make our world according to our vision, while a perfect organism would sit quietly and achieve little.