I am extraordinarily lucky to have a permanent job at a university that is less obsessed with publication metrics than many. I am appraised by my line manager once every five years, and I am expected to try to produce a few really good publications over that time rather than large numbers of papers that have limited impact. I am also encouraged to participate in promoting science to the public. This enlightened attitude provided me with the opportunity to write this book, and, although my life’s aim since my brush with malaria had been to understand why I existed, I only decided to try to write what I had learned and concluded in a popular book when I moved to Oxford in 2013. I knew I needed a year of largely uninterrupted time to break the back of my book-writing project, and I planned for 2020 to be that year, as by that time Sonya and I would be due a sabbatical. The pandemic intervened, so we had to delay our sabbatical by a year, but in September 2021 Sonya and I headed to the University of Queensland in Brisbane and I began to write.
I did everything rather back to front. I didn’t know what the fate of the book might be when I started writing it, and my initial aim was to write it for my children. However, when I showed draft chapters to my youngest two, Luke and Georgia, they told me it wasn’t for them, and they wouldn’t read it. I admit I was a bit dispirited. Nonetheless, colleagues and friends in Brisbane were more positive, saying they liked the idea of the book and they would love to read it, so I persevered, and as I neared the end of the first draft I started to think I might be able to publish it. A bit of investigation revealed I had three options. I could self-publish, and if I did this, I would be responsible for marketing the book and would likely only sell a few tens or hundreds of copies. Alternatively, I could work through one of the academic publishing houses and would be writing for scientists, and this became my fallback option. I’d need to strip all personal anecdote, humour and any hint of elegant prose from the text, but one of the university presses would deal with the printing and market it to an academic audience. Alternatively, I could work with a literary agent who would try to find me a publisher of popular science books and it might be more broadly read. Those in the know told me this was hard, and that many academics failed to be recruited by an agent, but given I’d written the text with my well-educated but non-academic grown-up kids as the intended audience, I decided to give it a go.
The first two agents I wrote to never replied, but the third did. I met up with her, she signed me up as an author to her literary agency, and I was over the moon. She explained that it was unusual to have a full draft of a book, and that I would need to write a proposal to pitch the book to a publisher. I did just that, and an editor who worked for Penguin Michael Joseph signed me up.
I knew what would happen next, for it had happened at every stage of my career. That night was sleepless, I felt that I was a fraud and that this shouldn’t be happening to me. My agent and my publisher had both made a dreadful call, and I was way out of my depth. I had had the same feeling when I won a scholarship to conduct graduate studies, when I was offered my first faculty position, when I was awarded my first research grant, when I was promoted to Professor, when I was appointed to Oxford and when the faculty of my department voted for me to be their head. But I knew what I had to do. I took Woofler for a long walk, and logically thought it through. My agent and my editor knew what they were doing. Both had worked with some great authors, and they were at the top of their profession. They had faith in me, so, although I still had my doubts, I owed it to them to produce the best book I could, as they were working hard to achieve the same outcome as I was – an informative and enjoyable book. I would be doing them a huge disservice if I were to continue to consider myself as an imposter. I was also determined to enjoy the experience, as I also believe I will only live once, so I should make the whole experience fun. I now get a kick from dropping into conversation that I have a literary agent and an editor and seeing the looks of disbelief on the faces of my colleagues, and after my editor told me my dog was soon to be famous, I ascribed a metric of success as the number of pets called Woofler I meet in the future. I assume those pets will be dogs, for what fool would call their cat Woofler? For that matter, Woofler is a pretty daft name for someone to give to a dog.
Although you may now consider me a bit of a simpleton for naming a dog Woofler, I am, like you, staggeringly complex. Or at least the chemistry that keeps me alive is. Prior to the brief scientific publishing detour, you will have come to appreciate quite how complicated we all are, and you will likely be wondering how life self-assembled the first self-assembly manual. We do not know for certain, but we have some ideas and mounting evidence, and I suspect it won’t be too long before scientists produce simple life in the laboratory from a cocktail of simpler molecules. Part of the trick is working out what those simpler molecules would have been on our young planet, along with the conditions required for them to assemble into the first living organism.
I’m going to assume that life began on Earth rather than in space. Even if life didn’t start on Earth, it is usually assumed to have begun on a planet or meteoroid rather than in space itself. A few researchers have championed a hypothesis called panspermia whereby life started on another planet before colonizing Earth. Panspermia does not solve the challenge of how life got started, but it does provide for a wider range of environments beyond those found on early Earth for where it could have begun. A downside is that the theory requires not only an understanding of how life began elsewhere but also an explanation for how it travelled between planets. This additional challenge, along with the sparsity of knowledge about the chemistry of other planets, means few scientists actively study panspermia, and I will discuss it no further, thus assuming that life began on Earth. Despite this assumption, many organic compounds do form elsewhere in the galaxy, including in nebulae. They have been detected on meteoroids, found on meteorites, and their signatures observed on other planets and in other star systems through the deployment of high-tech telescopes, but these finds are of organic molecules rather than of replicating life. Life probably began on Earth but was given a helping hand with much of the raw material that the first cells used coming to our planet from space.
The formation of the Earth, and the subsequent settling of its orbit into the habitable zone 150 million kilometres from the sun, provided necessary conditions for the emergence of life. When you think of what you need to live, you will probably think of oxygen, because without it you would die. Early life did not rely on oxygen, and it would probably have killed it. The atmosphere of early Earth during the period when the first life arose was very different from the air we breathe today. The first thick atmosphere was created by the collision of Theia with Earth, and scientists think it consisted primarily of nitrogen, carbon dioxide, water vapour and sulphur dioxide, with oxygen being nearly entirely absent. The surface of Earth in its youth was hot, and the first atmosphere had a high concentration of greenhouses gases, and this meant it took time for the Earth’s surface to cool to a temperature where water could occur as a liquid – the first key requirement of life. By 3.9 billion years ago, the Earth had cooled sufficiently for this to happen. The first life is thought to have evolved quite quickly once liquid water was available, which means that the climate of the early Earth when life formed was much hotter than it is now. Our planet’s average temperature would have been close to the boiling point of water, compared to the chilly 13.9 degrees Celsius of today.