Sci-fied reality is very much here and now. The twenty-first century arrived almost twenty years ago, and it is no surprise that flying taxis, choppers in space, bot-human love stories or even the existence of a new species existence get written every other day. Alongside all of this, there are scientists like Adam Rutherford, who says that the ultimate storage device will be made of DNA.

This, of course, raises the important question: What are humans really, when it comes to consideration of genetics? Much as we think of ourselves as sophisticated species, we have fewer genes than a grain of rice. Yet, we are the only ones to ask, “What are we?” This enigma lies at the heart of Rutherford’s new book, A Brief History of Everyone Who Ever Lived.

A riff on Stephen Hawking’s most accessible work, this book is heavy on ambition while being quick in pace and sweeping the reader off their feet from the word go. Rutherford, a geneticist who hosts the popular BBC Radio 4 show, Inside Science, sets the bar high by explaining how homo sapiens ought to understand the basic building block of life, the gene, to understand who we really are:

“Our genomes, genes and DNA house a record of the journey that life on Earth has taken – 4 billion years of error and trial that resulted in you. Your genome is the totality of your DNA, 3 billion letters of it, and due to the way it comes together – by the mysterious (from a biological point of view) business of sex – it is unique to you. Not only is this genetic fingerprint yours alone, it’s unlike any of the other 107 billion people who have ever lived.”

Perhaps to drive home this point, Rutherford serves up a crash course on the side in understanding gene studies, involving genome sequencing, DNA, genomes, alleles, chromosomes and more. To understand the gene, time travel is a must. After all, out of the six homo species, only ours has survived, having emerged some 30,000 years ago. The others were on earth for about 2 million years.

Rutherford explains that the simple chain of “monkey-ape to ape-man, to man-ape” is an untruth. The first in a series of untruths that he illuminates in the book. His other bone of contention is “the culturally ubiquitous idea that genes are fate, and a certain type of any one gene will determine exactly what an individual is like.”

All those myths

As the writer shuffles the deck of the cards we have been dealt, the realisation that ours might not be the first technological and cultural species gains currency. Cave paintings have in fact been attributed to Neanderthals by some. And, lest we contest our brutish selves, there is a theory that we perhaps hunted and made a meal of Neanderthals as well. But the beautiful irony of nature is such that some of us do carry Neanderthal genes.

Rutherford’s explanation of how 107 billion human beings came to inhabit different corners of the world goes up against the concept of race. He writes: “The latest analyses incorporate the fact that the current residents of a geographical area are not necessarily very good representatives of the residents of the deep past. Today’s Siberians are more like East Asians, but the ancient Siberians were more like Native Americans, mixed in with some northern Eurasian.” Identifying races, then, is pretty much like creating patterns in a star-studded sky.

Another wrong turn in our understanding of things, argues Rutherford, might be based on personal genome analysis, which has become a cheap and easily accessible service. The writer is at pains to point out that possession of certain genes cannot and do not guarantee you will contract a particular disease. It can only speak of your likelihood of falling prey to it, with the odds being calculated by comparing your score with the average.

The 3 billion letters of our DNA are ready to be read, but how they need to be read is an important question, warns Rutherford.

Where do we go from here?

The next question Rutherford tackles is: “Are we still evolving?” We aren’t inching towards the X-Men, he reasons, but we are certainly mutating. Vaishyas in South India are cited as proof, as seen in the abnormal reaction to many members of this “caste” to anaesthesia, ranging from no result to even death. Rutherford explains:

“By looking into their genomes, we learnt of a single change – a random switching of a single letter of the gene encoding the enzyme butyrylcholinesterase (BCHE), which normally helps degrade molecules in the blood similar to the anaesthetic.”

The startling fact that is this realignment of the allele – the form, dominant or recessive, in which a gene exists in an individual – in the Vaishya bloodline began at least 1,900 years ago. For better or worse, it appears, we are a species on the move.

On the lighter side, Rutherford offers scoops on the Human Genome Project (which mapped each and every gene in the human genome from both a physical and a functional perspective). For instance, scientists placed bets in a bar on the number of genes human beings would turn out to have as determined by the project. Rutherford’s quirky humour is often tucked away in the footnotes, throwing up delightful nuggets of information, such as the whimsical scientific names of certain species – “gorilla gorilla” is a scientific name, as is “extra extra” for a certain mollusc)

The appeal of this essentially scientific book lies in its ability to both inspire and provoke thought, thanks to Rutherford’s unique, rather poetic view of genetics. When a writer says, “You carry an epic poem in your cells,” the reader has no choice but to pay attention.

A Brief History of Everyone Who Ever Lived: The Stories In Our Genes, Adam Rutherford, W&N.