What Dawkins is doing here is trying to indoctrinate young minds, slipping his ideological message into a text which purports to be the facts and nothing but the facts, the trick worked by preachers throughout the ages.
In content Richard Dawkins’ The Magic of Reality is pretty much like any good illustrated Book of Knowledge, of which there are many. But to really get such a message over requires a charismatic messenger and so The Magic of Reality will reach further than any other Book of Knowledge. As such it is mostly fine – you can safely give it to any child, knowing that virtually everything in it, is as Dawkins says, is the truth about reality. But Dawkins has not escaped ideological bias. At times he insist on his own interpretation of the gospel: he belongs to the Olden Day Church of the “Modern Synthesis” or the Sect of the Selfish Gene (actually a declining minority amongst biologists). This doesn’t matter for most of the book except that, as with the preachers he reviles, there is a whiff of “putting the fear of Dawks” into them. On p74-5 he describes all animals as “survival machines[s]. for genes and then: “Next time you look in the mirror, just think that is what you are too.” It’s not much of a match for fire and brimstone but it left me feeling very queasy. I wouldn’t be telling young people that they’re nothing but survival machines for their genes. It’s not true, for a start. We are not merely puppets of the genes – they take orders too.
What Dawkins is doing here is trying to indoctrinate young minds, slipping his ideological message into a text which purports to be the facts and nothing but the facts, the trick worked by preachers throughout the ages. Some of the strangest creatures on earth have recently shed new light on nature’s mysterious pattern forming programmes. The discovery of the hox genes in the 1980s was the first breakthrough in understanding how the forms of all creatures are made and how they evolved. All animals, whether insects or mammals, are highly modular: evolution has occurred through copying of modules with subsequent modification of what were once identical parts (homology). So all insects have segments and all land animals have four legs (tetrapods). These programmes seem to be highly constrained and conservative. Birds are tetrapods and whilst it might be advantageous for a bird to have four legs and two wings, evolution has not managed this: the forelimbs can become wings but extra limbs cannot be achieved. In fact, it hard to know how true novelty ever emerged.
In a recent paper in Nature (2011, Vol 273, pp83-86) a French team have shown that there is an exception to every rule. Primordial insects might have had wing-like appendages on all the segments but long ago the hox gene suppressed wings on all but two segments: the second and third thoracic segments. The treehoppers have astonishing varied appendages, “helmets” which may be used for camouflage or to break up the creature’s outline or in some cases to form protective spines. The range of these helmets in different species is so vast and grotesque that the creatures look like sci-fi aliens. Benjamin Prud’homme and Nicolas Gompel’s team has shown that these weird shapes are actually formed by the normal wing hox genes but acting on the head segment, a place where they are suppressed in ever other species of insect. They say that this is an unprecedented example in 250 million years of insect evolution. And beyond that, the helmets show what nature pattern forming genes can do when they have a free hand. Wings have to obey the laws of aerodynamics so they are constrained in the forms they take but these helmets can take pretty any form they like, although they obviously fulfil some function. The pattern forming genes work by switching on an off in cascades, accelerating growth in one area, slowing it in another. The results are breathtaking. The helmets are not variations on a theme but a complete gallery of morphs. Some seem to be mimicking other creatures such as ants; one would make a rather cool arced earring; one is a leaf mimic, and so on. In the technological realm we now have 3D printers, using stereolithography to build, layer by thin layer, any pattern you like, laid down by a computer design. The pattern is built by resin deposition in accord with the parameters laid down by the computer programme. The treehopper seem to foreshadow nature’s stereolithography by means of hox genes. In Dazzled and Deceived I investigated the genetic patterns behind mimicry and camouflage. Almost all of this work had been done on butterflies; Prud’homme et al have begun the process of unlocking the treasure trove of mimetic pattern-forming in the wider natural world. Credit: B. Prud'homme et al., Nature, 473 (5 May, 2011) The story of the hour is the prospect of curing mitochondrial diseases by implanting a third person’s mitochondrial genes in an egg during IVF. It’s controversial because it raises the spectre of human genetic engineering and would require new legislation to legalise it. But a bit of background will help us here.
Mitochondria are the cell’s batteries, little structures inside every cell that provide our energy. They have a most curious property in that they have their own DNA, separate from the rest of our DNA, that is only inherited from the mother. The other oddity about the mitochondrion is its genesis. It is now virtually certain that mitochondria were once free living single celled creatures. Life in those days – we’re talking of around 2 billion years ago – consisted only of single-celled creatures: life was a matter of one cell engulfing another and digesting it: the war of the cells. It wasn’t a pretty world, by our standards, and this went on for about 1 billion years before multicellular organism began to evolve. But sometimes, instead of one cell consuming another, both cells found an accommodation: one continued to live inside another and both benefited: symbiosis. This also happened in the line that led to plants: the green of plants comes from the photosynthetic chloroplasts, also once free-living organisms. Over time, many of the genes in the mitochondria have been lost or been incorporated into the host genome – only 37 remain. But the mitochondria are vital – if they seriously malfunction, life is not possible. So when genetic modification of mitochondria is proposed what we are really talking about is not human genetic modification but a form of bacterial modification: the bacterium just happens to be part of us. We don’t scruple to tinker with our most basic bits of plumbing. If the heart is failing we implant a pacemeaker. This is not considered to be dehumanizing. But tinkering with our genes is thought by some to transgress human integrity. This is illogical. The team in question is at Newcastle University and the head, Professor Doug Turnbull, put it succinctly: "What we've done is like changing the battery on a laptop: the energy supply now works properly, but none of the information on the hard drive has been changed”. Photosynthesis is the most important chemical reaction on the planet. It powers all the living energy systems on earth, allowing plants to grow, animals to move and cycles of weather to support life. It produces the biomass needed to feed the animals (including us) and also provides us with all of our materials, bar minerals and metals. Finally, through fossil biomass it provides most of our transport, home and industrial energy.
The pressure on natural photosynthetic systems and exhaustion of fossil stocks make direct mimicking of photosynthesis a key goal. The reaction is purely electrochemical- there is no vitalist living magic about it, so we ought to be able to copy it. There are many current strategies but the most promising and imaginative is Carlo Montemagno’s. He has harnessed modules from three totally separate living systems – the universal ATP energy motor from bacteria; the light harvesting pigment bacteriorhodopsin from Halbacterium salinarium and a remarkable foam from the Tungara frog. Lest you think that since these are all from living systems, life is required, Montemagno has created the same effect using block copolymers instead of the foam. The advantage of the foam is that one can now envisage huge vats of foam photosynthesis plants, with the glucose being drawn off for further processing. These separate systems work happily together, with light and simple phosphates, to build biomass. Industrialised, these light-harvesting biomass-creating foams could operate in barren regions, leaving fertile land for food production. In March, Montemagno’s foam won the $50,000 Earth Award. It is high time we learnt this trick. Rather shamingly,another animal has beaten us to the goal of exploiting photosynthesis. The sea slug Elysia chlorotica feeds on algae and it has evolved to incorporate some of the algal genes, allowing it to live without feeding. The slugs are appropriately green in colour. . We don’t have to turn our own bodies green but the slugs show that the plants’ trick can be harnessed outside the plant context. Perhaps we should pension off the world “sluggish” and get ourselves up to pace with light harvesting. Jonathan Latham's Guardian article today suggests that genes are mostly NOT responsible for diseases. He cites the relative failure of the Human Genome Project, now in its 10th year since partial completion, to produce medical benefits.
This attitude is highly irresponsible, feeding a fear of things genetic (as in GM food) that is second only to thing nuclear. People forget, or never knew, that genes don’t simply set you going as a human, with your parental inheritance etc. They are active all the time in every cell making the chemicals the body needs to function normally. In a healthy person, only a limited number of the 25,000 or so genes are active in any one type of cell. That way they can make just the chemicals needed to metabolize sugars, or create the light-sensing pigments of the eye, or grow nails or protect against infections. If a gene gets out of control a body function may be compromised or cancer may result. As far as the human genome project goes, it is well known that a limited number of serious diseases are caused by a single gene errors (so-called snips – single nucleotide polymorphisms). Some of these are :Huntington's disease, neurofibromatosis type 1, Marfan syndrome, cystic fibrosis, sickle-cell disease, Tay-Sachs disease, Hemophilia A, Duchenne muscular dystrophy, and Lesch-Nyhan syndrome as well as common and less serious conditions such as male pattern baldness and red-green color blindness. These are the low hanging fruit Many other serious diseases – such as diabetes, heart diseases – Alzheimer’s, are multi-gene diseases and much harder to understand. Of course many conditions are caused by infective organisms or environmental toxins but these all still have to interact with the body’s genetic mechanisms. You can’t study these without taking the gene cascades into account. I fear that Latham’s article will encourage the obscurantist tendency and greatly hinder medical research. Craig Venter’s synthetic bacterium has so far been presented in terms of stark opposites: the prospect of miraculous new synthetic organisms to clean up the earth, versus the scientist playing at God. The reality is more prosaic. Venter has laboriously synthesized, by purely chemical means, a one-million-base-pair bacterial genome, inserted it into the empty shell of a cell and the result has reproduced itself quite happily as a working bacterium: a “synthetic” life form. This is only impressive to those who could never quite believe that DNA was “only” a chemical. There isn't a biologist in the world who didn’t believe that a chemically synthesized DNA would be identical to a “natural” one. Venter’s feat is rather like copying the text of a Shakespeare play by hand, giving it to a theatre company, and being surprised that it comes out sounding the same.
Venter’s aim is to create useful new synthetic organisms. But exactly this kind of genetic engineering has been commonplace on an industrial scale for decades. The first great breakthrough was synthetic human insulin for diabetics in 1982: the insulin gene is inserted into the common or garden intestinal bacterium E. coli and the bug churns out insulin which is harvested in huge quantities. This has been the standard method of making insulin ever since. Venter’s experiment does not take us any nearer creating the organisms he says he wants: biofuel bugs, artificial photosynthesis bugs, CO2 scavenging bugs etc. What Venter has done is similar to, and less impressive than, the cloning of Dolly the sheep. In Dolly, the genome of a higher organism, a mammal, was inserted into an empty cell and developed into a full-blown Dolly sheep. Venter’s bug is just a bug. We have known since Dolly that complete genomes inserted into sucked-out cells function perfectly normally to create the organism specified by the genome and not by the original host cell. And if we are worried about playing God, think again about Dolly. Sheep, cattle, pigs, chickens and our crops are not natural at all, they were genetically modified, and profoundly so, by breeding experiments conducted thousands of years ago by the first pastoralists and agriculturalists. We have been changing the genomic population of earth on a vast scale for thousands of years. A final point. As with all cloning, Venter had to insert his synthetic genome into an existing cell, the genetic contents of which had been sucked out. At present, no one knows how to synthesise all of the components of a working cell from scratch, although this may one day be possible. DNA is superstitiously regarded as the key to everything – the blueprint. This is wrong. Life is a collaboration between the rather passive coding properties of DNA and the dynamic self-organising properties of chemicals such as the lipids that form the walls of animal cells, or the proteins that spontaneously self-assembly to create fibrous structures and lock-and-key shapes for enzymes. The only part of Venter’s work that did make me smile was his incorporation of an encoded message into the genome. Any researcher cracking this watermark code will find an email address to write to to claim their prize. This is cool but again it won’t surprise any biologist. DNA is just a string of letters written on an architectural molecule: In 2006 Paul Rothemund, a young US biologist, made the cover of Nature magazine by creating synthetic DNA smileys. You can write really any structure you like on DNA. You could inscribe a Shakespeare sonnet in a genome if you were so minded. Venter’s coup is a huge success in terms of publicity. If it helps him achieve his ambitious and worthwhile ends, fine. But don’t let us get too excited about this over-literal and redundant experiment. |
AuthorI'm a writer whose interests include the biological revolution happening now, the relationship between art and science, jazz, and the state of the planet Archives
March 2016
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