But it’s replication that causes the most problems. It used to be thought of as a chicken-and-egg problem: DNA makes proteins and DNA needs protein enzymes to replicate. So how did this ever start? But the most likely answer is neither chicken nor egg but rather a chegg or an ecken. RNA is an intermediary between DNA and proteins, but it can also replicate itself with no enzymatic assistance.
In the second book, Rutherford describes the ingenuity of research in pursuit of modified life-forms. The DNA/protein system of life is universal on Earth — just four bases in DNA and 20 amino acids in proteins. But biologists are now creating novel substances: DNA analogues with additional bases or a different sugar backbone - xeno-nucleic acids or XNAs. The antiviral drug acyclovir, for example, commonly used to treat cold sores, contains a novel synthetic base that gums up the viral works.
Rutherford tells his stories with great brio and a disarming line in personal commentary (he was a lab geneticist before becoming a science writer and broadcaster). DNA is a code, a language with only four letters - A, T, C, G, for the bases Adenine, Thymine, Cytosine and Guanine — and he cleverly exploits this with telling linguistic analogies. It used to be thought — indeed Francis Crick called it the Central Dogma (for which he is correctly ticked off by Rutherford) — that DNA could only be translated into RNA, and not the reverse. Reverse transcription is big business these days, but it’s inaccurate: Rutherford used Google Translate to back translate into the home language to demonstrate the point. Using Czech, the message that “But DNA copied from RNA is riddled with errors” becomes reversed in meaning on back translation.
In fact DNA and language are rapidly converging. When, in 2010, Craig Venter created both a synthetic cell and a media storm, he inserted into the organism “watermark” messages, one being a passage from James Joyce’s Portrait of the Artist as a Young Man translated into DNA code, which made it, according to English author and journalist Charlie Brooker, “the world’s most pretentious bacterium.”
George Church, a DNA researcher at Harvard, has encoded one of his own books in DNA by translating the zero/one digital code into DNA code. Although at present it’s a lumbering process to extract the information again, the density of storage is many times higher than that of conventional computer data storage.
At fewer than 250 pages, Creation is the perfect primer on the past and future of DNA. When I began to study science it never occurred to me that, within my lifetime, we would have gone so far towards solving the eternal mysteries. Well, we have.