The first of what the organisers hope will be a series of Newbury Talks took place on Sunday in the bar of The Corn Exchange: Herding Hemingway’s Cats – How Do Our Genes Work? by Dr Kat Arney. Her book of the same name has recently been published by Bloomsbury Sigma.
In fifty minutes it’s impossible to do more than sketch a brief outline of such an enormous, complex and ever-changing subject. The talk provided as many questions as answers – not necessarily a bad thing – and was a lively and engaging introduction to something we accept exists but are probably ignorant about. I certainly was – a bit less so now, though.
Most people agree that life has evolved over time: variations constantly occur and are passed on and gradually become dominant traits if they present the species with an advantage. It’s also widely accepted that the process is run by genes which trigger chemical reactions. Less well understood is how these are all switched on at the right time. Thanks to some well-chosen analogies I for one am now slightly less confused. It seems to resemble the preparation of an almost unbelievably complex banquet in which about a trillion dishes, some identical and others not, need to be created from scratch using about two million recipes written in code, some of which can in some circumstances be varied and all of which must be switched at the right time and in the right order if the results are to be as good as, and ideally very slightly better than, the previous meal. No pressure, then.
It’s the kind of thing that makes me slightly light-headed just thinking about it. Even after years of study, Dr Arney admitted to much the same feeling. Some of the statistics are, as she put it, mind boggling. If unravelled, the DNA in each of our cells would be over 2 metres long: if all the DNA in each cell were joined it would stretch from here to the moon and back 750 times.
We humans like to think we’re a bit special: but another, more humbling, statistic is our own geonomes are scarcely more complicated than those of a fruit fly. This suggests that the trick in the whole evolutionary process is not so much what is in the DNA itself but how it is combined and when and how the result of each combination is activated. The raw material is important but the cooks are more so. This makes sense to me: you could give me and Gordon Ramsey the same ingredients and even the same recipe books but I don’t think anyone would doubt who would produce the better meal. Of course, give me 10 years of practice and countless duff results and I might be able to match him. I guess this is the equivalent of evolution: time spent by nature discarding that which doesn’t work and replicating that which does.
One of the many troublesome aspects of the whole business is the fact that about 98% of the DNA appears to perform no obvious function. This is sometimes (wrongly in Dr Arney’s view) referred to as ‘junk DNA’. As natural selection has in most cases produced species that are supremely efficient and perfectly designed for their environment, it does seem odd that their raw material should contain so much wastage. More likely is that this is required for some currently unimagined and vital role we have yet to grasp: much like all that dark matter and energy in the universe, perhaps.
The cats of the title aren’t a pun on Dr Arney’s first name but refer to the six-toed ones beloved of the manly American writer. Their defect has now been traced to a faulty control switch in a completely different part of the geonome from that which is responsible for making the cats’ paws: to return to the restaurant analogy, I guess this would be like a misprint in or a mis-reading of one menu detail that produces in a few cases a slightly different dish further down the line. In normal circumstances, this would be unlikely to be frequently repeated unless these polydactyl felines became isolated and started to interbreed. In a sense, I suppose that human intervention has led to exactly this result: perhaps inspired by people following Hemingway’s tastes, perhaps because of mild evolutionary advantages the extra toe confers to cats on ships, there are now more six-toed cats on the eastern seaboard of America than nature might have intended.
One obvious danger follows from this; for any group which is descended from a small number of ancestors (as these cats would be) would have little genetic diversity and so be more vulnerable to infections and disadvantageous mutations. An example is provided by the current threat to bananas. Almost all are monocultures, essentially clones of one disease-resistant variety identified after a global outbreak decimated out the commercial plantations in the 1960s. They are now menaced by a mutation of the same fungus that wiped out their predecessors.
This is perhaps one ethical problem posed by our intervention in the evolutionary process. Dr Arney touched on others, including the risks of geonome analysis. There are always people or organisations that wish to pervert any knowledge: the risks here seem far greater as genetics goes literally to the roots of our humanity. Even if a government’s interest were truly altruistic (which few would accept), one must never forget the law of unintended consequences. What, for instance, could have seemed more beneficial than the introduction of cane toads into Australia in the 1930s?
On the way home, I mentioned to one of my sons how the 1980s Singapore government paid for the honeymoon when two graduates married. This seems a fairly benign, though rather crude and slightly creepy, version of genetic engineering. Take it a few steps further – say, the benefit is only paid if you marry someone of your own race – and people would become more uneasy. Introduce the results of genetic research and the identification of less obvious traits and the risk will be of governments forbidding certain unions altogether on grounds of public health or perceived ‘unsuitability’ in other ways, something not even Orwell’s 1984 imagined. Yet the combination of scientific research and human nature has made this a real possibility. On the other hand, many diseases can be better understood, treated and perhaps eradicated through genetics, just as smallpox was through vaccination, a procedure which excited similar disquiet when first introduced (and which, in some parts of the world, still does). Selective breeding of animals, six-toed cats amongst others, perhaps produces similar dilemmas, although in these cases we are only speeding up intra-species variation rather than trying to re-wire the whole thing from the inside. Knowledge certainly breeds responsibility, particularly in genetic science.
So, hats off to Kat: the talk was stimulating and interesting, delivered in a conversational style that perfectly suited the setting. My two teenaged son enjoyed it as well. For those of you who didn’t make the talk and would like to see it, it will soon be available on the Penny Post YouTube site. For those of you who want to find out more about this subject, Dr Arney’s book Herding Hemingway’s Cats is available from all good bookshops, including the Hungerford Bookshop.
May this talk be the first of many more. Once the details of these are decided they will be publicised, in Penny Post and elsewhere. See you there.
PS. You may have other views on all this. You may also think that this is a hopeless, inept summary of the talk and the issues surrounding it – I am no scientist. If so, please post a comment in the box below.
Tales of a Six-toed Cat