Herding Hemingway's Cats


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Herding Hemingway's Cats by Kat Arney, 2016, Bloomsbury Sigma. Paperback runs $18.00 US, 9.99 UK.

If you are interested in molecular genetics and genomics, and want some light reading on the subject (as opposed to a heavy textbook), this is a book to consider.

It's written very well and reads easily like a novel. It considers the human genome project and its aftermath, particularly the attempts to make sense of the torrents of information provided by automated gene sequencing.

It pays a lot of attention to what journalists call "junk DNA" (biologists don't like that phrase, for reasons given in the book). It discusses the variety of things included in this category, such as DNA sequences producing non-coding RNA (nobody's sure what all that RNA is doing) and more peculiar things like transposons. There are discussions of how genes are turned on and off and so on. (The ENCODE project concluded that some 80% of 'junk DNA' isn't junk at all, but like everything, that's controversial.)

Some excerpts from the introductory chapter:

"When he and I were students at the end of the 1990s, we were reading DNA in tiny chunks, a few hundred letters at a time... Today an entire human genome can be read in a few days. But rather than clarifying the content of our genes and how they work, things have got very complicated indeed.

The problem is that we were not put together by an anally retentive designer with the celestial equivalent of thick rimmed glasses and a hipster beard. Instead, our genome has been sloppily patched together over eons by evolution, the master bodger. And for want of a more poetic way of putting it, it's full of rubbish." (p.16)

"By 2001, after a decade of work...UK Prime Minister Tony Blair and US President Bill Clinton linked up by satellite to reveal humanity's inner secrets to the world... Clinton claimed that 'Today we are learning the language in which God created life.' And lo, there was much hyperbole.

There's no doubt that putting together a draft human genome - and it was definitely a draft, full of errors and gaps - was a hugely impressive technical and collaborative achievement, and I don't want you to think that it wasn't.... It took tens of thousands of years for humanity to get to this point, so it was definitely worth a pat on the back and one hell of a party. But when people started to look closely at the contents of our genome in the years following the glitzy announcement, it turned out that maybe things weren't quite what many people had expected. For a start, where were all the genes?"(p.19)

[It appears that by some counts, humans have somewhat less than 25,000 protein-coding genes. How does that compare?]

"There was perhaps an assumption that because humans were clearly the most awesome animals on the whole damn planet, we would need a huge number of genes. Not so. Many organisms have far more genes than we do. Water fleas the size of grains of rice have 30,000 genes... Plants are particularly blessed in the gene department: grapes have around 30,000, golden delicious apples clock in at 57,000, and wheat has nearly 100,000...

There's also the question of what is a gene, anyway? ... They specifically excluded stretches of DNA that are read into RNA... but don't actually direct the construction of proteins. As we'll see later on, there are a huge number of these so-called non-coding RNAs produced across the genome, yet little clarity about what they all do and which, if any, of them should fall under the banner of 'genes'." (p.21)

"One of the most intriguing results of the human genome project was the confirmation of earlier, less sophisticated analysis suggesting that about half of our DNA is stuffed full of short repeated sequences. As an example, your genome is peppered with about 1.1 million copies of a small repeated DNA phrase called an Alu element, around 300 DNA letters long, which we share with other primates like chimps and gorillas. Alu, like many of the other repeated elements in the human and other genomes, has come from a transposon - a kind of genetic 'virus' that can randomly copy and paste itself around the genome, making more and more versions of itself. Exactly when and where we picked it up isn't entirely clear, but it must have invaded since primates split off from other mammals around 65 million years ago." (pp. 21-2)

So that's basically what the rest of the book's 250 pages are about. And it gives a taste of the non-textboookish writing style.