The Body: A Guide for Occupants (2019) is an entertaining and fact-filled account of how we all work. With his trademark wit, Bill Bryson explains the astonishing ways in which our bodies are put together, and what goes on inside them.
Imagine that you had to build a human being from scratch. How would you go about it? What building blocks would you need? How much would it cost?
Well, in 2013 the UK’s Royal Society of Chemistry took on the bizarre task of estimating the specific cost of building actor Benedict Cumberbatch. According to their calculations, you’d need 59 different elements, although only six in any serious quantity – carbon, oxygen, hydrogen, nitrogen, calcium, and phosphorous. Those elements would cost you £96,546.79 - labor and taxes not included.
But that’s only one estimate. An episode of the science program Nova, broadcast by US network PBS in 2012, pegged the cost of building a human at a mere $168.
Even the cost of the materials for building a human body, then, is uncertain – but more to the point, even with all those materials, the actual act of building a human being would still be beyond us. All we’d have would be a pile of inert elements. The miracle of life isn’t something you can create simply by sticking stuff together.
In fact, we can’t even say with certainty where life begins. The cell is the essential life-giving unit that we’re all made up of. But how exactly do cells coordinate themselves to create a functioning human being? Science still can’t tell us the full story – which is wondrous in itself.
Science can tell us a lot, though. Inside the nucleus of each cell is a meter of DNA. Made up of chromosomes and genes, DNA contains the information needed to make you. It’s amazing to think that your DNA is the product of generation after generation of transmission: the information encoded in your genes links you directly to your ancestors of some three billion years ago.
Some people think of the body as a machine, but it’s so much more mysterious and impressive than that. On all the time, it usually goes for decades without needing repairs, and all it needs to run is water and food. Plus, it’s conscious.
It’s also remarkable to think that we arrived here through evolution, having started off as nothing more than a few cells in the ocean. All the developments that humans have undergone since that time have basically been wonderful accidents.