Because it's there
Why is it necessary to take mice up Everest to study any alteration to their erythropoietin levels (31 May, p 7)? Surely these changes set in at lower altitudes, or could be reproduced using a suitable atmospheric chamber. Might this be a publicity stunt for some mountaineering scientists?
Blind camouflage
How do cephalopods manage to match their camouflage to their environment so accurately when they can see only green, and do not look at their skin (26 April, p 28)? A possible answer came to me while reading your article on cuttlefish. To return to a basic tenet of evolutionary theory: biological adaptations arise through blind selection, not conscious processes. Similarly, a cephalopod does not need to detect directly whether its skin has generated the appropriate colour scheme or texture 鈥� only to figure out its surroundings.
Among red-and-blue speckled spiky coral, for example, it would be able to detect enough about the coral for its camouflage mechanism to make the right pattern. The chances are that any coral of a given speckledness and spikiness in the cephalopod’s environment would have the same colouring. There is no need for it to check the matching, since its predators do this. Cephalopods that get it right survive to pass on the right combination of genes.
Have experiments tested this 鈥� for example by permuting environmental characteristics and threats and observing any camouflage confusion?
For the record
鈥� In the article “Alps are no go without snow” (24 May, p 18) we said the measurement stations are between 200 and 1800 metres above snow level: that should have been above sea level. The study counted snow days, not snowfall; and the 60 per cent decline was for the Swiss plateau between Zurich, Bern and Basel, and not the Swiss Alps.
鈥� In the graph accompanying the article on food supply (14 June, p 28) world population should have been in billions, not millions.
鈥� We said that the Transpolar Drift Stream was driven by westerly winds (7 June, p 42). They are easterlies, blowing from the east.
Cochrane's testing legacy
Hazel Muir laments the fact that few, if any, social policies have been introduced on the basis of valid evidence of benefit, let alone cost-effectiveness (24 May, p 40). She makes frequent references to the contrast with medicine, in which no procedure or drug is now introduced into clinical practice or public health policy without evidence of benefit from randomised trials 鈥� most often multiple trials, summarised by a statistical overview or meta-analysis.
The randomised controlled trial (RCT) was introduced into medicine from agriculture by the statisticians Austin Bradford Hill and Richard Doll. It was the late epidemiologist Archie Cochrane at the Pneumoconiosis Research Unit in Penarth and then the Epidemiology Unit in Cardiff who did more than anyone to popularise randomised trials and demonstrate their unique and unassailable role within medicine.
Cochrane never conducted a substantial randomised trial himself. He did stimulate countless others, most notably Sir Iain Chalmers in Oxford, who set up the Cochrane Collaboration, a global network which aims to identify every RCT within medicine, summarise the overall results in meta-analyses and identify those activities for which valid evidence is lacking.
Cochrane believed that the opinion of “experts” should never be accepted as truth, and he used to point out that without randomised trials “one will never learn anything”. In fact, he urged that randomised trials be conducted within every field of human activity.
Muir refers to uncertainties in how prisoners should be treated. In the 1960s Cochrane repeatedly urged the randomisation of different punishments in discussions with lawyers. Together with John Palmer, a social scientist working in his research unit in Cardiff, he set up two randomised trials to evaluate the punishment of school pupils for late arrival at school, and for smoking. He never managed however to persuade legal friends to adopt the same strategy and he always regarded this as one of his greatest failures.
Another area in which Cochrane challenged the opinion of experts with evidence from randomised trials was in food policy. One randomised trial showed that the addition of iron powder to white flour, a measure which had been introduced in 1940 and still continues, had no detectable benefit. Others examined the effect of “welfare” and “school” milk 鈥� distributed free to infants and young children in the UK from 1941 until Margaret Thatcher, then the education minister, notoriously abolished it in 1971 鈥� on their growth. A particular triumph in these trials was that they were paid for by the then Ministry of Health. The representative of the Ministry explained, however, that funding for the trials had to come from his own personal research budget rather than from general Ministry funds, because the Minister could not be made to appear to question the validity of the policies for which he was responsible!
Is there anyone now who will and can persuade, cajole, coax, persuade, wheedle, entice or inveigle our politicians and social scientists to evaluate their opinions and their policies in properly designed and adequately powered randomised trials?
ET's waving a wand
The article “Don’t expect ET to be like us” (31 May, p 21) covers some of the inadequacies of the SETI programme but does not go far enough. It omits the “magic” factor: as Arthur C. Clarke said: “Any sufficiently advanced technology is indistinguishable from magic.”
So any communication system used by an advanced civilisation would probably look like magic to us. And how exactly do you detect, or figure out that you have detected, magic? Consider the plight of a medieval scientist trying to detect our TV transmissions.
It seems SETI assumes that everything that is out there to be discovered has already been discovered and that in a thousand years we will still be using the same communication methods we use today. I seem to recall that towards the end of the 19th century a similar attitude was very strong. Many scientists thought that we had discovered everything and that all that was required was a refinement of this knowledge. And then several discoveries made us realise that there was a lot more to learn about our universe.
My bet is that one day we will find a much better way of communication than radio waves. For the moment let’s just call it magic.
Social Credit and spending
The problem of getting people to spend free money hand-outs 鈥� like the American rebates Jim Giles discusses in “Single tax rebate won’t get US spending” (7 June, p 6) 鈥� rather than save them has interested unorthodox economists for some time. None was more unorthodox than Frederick Soddy, winner of the Nobel prize for chemistry, who got called a crank for questioning the way credit is conventionally created.
A fellow sceptic, the engineer Clifford Hugh Douglas, sought to revolutionise the distribution of credit by subtracting the sum of the actual money in the economy from the potential value of the economy working at full capacity, and distributing the money to pay for presently unrealised capacity through an unearned income for all called a National Dividend. The problem is that people could stick that cash in their mattresses.
Supporters of his “Social Credit” system eventually supported the “discounted price” system, in which people could buy goods at cost, the producers being given their profit margin by the government 鈥� so people could only benefit if they spent money.
The most direct system of encouraging spending was that devised by Silvio Gesell, whose supporters included not only the American-born poet Ezra Pound, writing in Mussolini’s Italy, but also regular economists like Maynard Keynes and Irving Fisher, who urged American communities in the Great Depression to circulate Gesell’s stamped money on a neighbourhood self-help basis. Gesellian stamp money lost value at regular intervals unless you stuck a stamp on the notes.
Keynes’ admiration for Gesell is such that the Keynesian system of inducing slight inflation to stimulate spending comes under suspicion of plagiarism 鈥� but if so Keynes should have incorporated Gesell’s whole theory, including the measures to stop money disappearing into the bolt holes of landed property and raw materials. It is no exaggeration to cite this lacuna on Keynes’ part as the source of our present economic woes.
Forest fight
Fred Pearce assumes that the forest land used for palm plantations was cleared primarily for this purpose (31 May, p 6). However, palm planting is often simply the excuse loggers use to get hold of the land and the rights to log the forest. Such loggers often bribe officials to get the concessions. Frequently, having logged all the valuable timber, they disappear with the cash, abandoning the land. Your report “New Guinea forests wrecked” (7 June, p 6) indicates where they are now operating.
If abandoned logged forest in Papua New Guinea and Papua Barat, Indonesia, is subsequently planted with oil palms or other “permanent” crops, it cannot be right to condemn those planters for the acts of the loggers that preceded them. Instead, it would be better to look at the science of maintaining the quality of their soil for the long term. Restoration of the original mix of wild species that existed prior to logging is not possible.
Femtohazard
Gabriel Bodard objects to health concerns about home-based cellphone base stations being described as a “marketing” problem (26 April, p 20), but in this case the description is accurate. Femtocells, which only need to reach out a few hundred metres, put out considerably less radio-frequency energy (typically less than 10 milliwatts) than the phone itself 鈥� typically more than 200mW, and more when it is communicating with a base station up to 15 kilometres away.
So anyone who is worried about electromagnetic pollution enough to be scared of a femtocell base station will have no problem, because they will not have a cellphone. For those who do, the problem is one of understanding, solvable by marketing.
Peak soil
William Stanton observed that, as oil is needed to work the farm machinery and natural gas is needed to produce the synthetic fertiliser used in grain production, the phenomena of “peak oil” and “peak gas” will inevitably lead to “peak grain” (31 May, p 23). The amounts of energy involved are indeed huge: it takes at least 35 megajoules to produce each kilogram of nitrogen in synthetic fertilisers, and 80 million tonnes of such fertiliser is used globally each year.
There are, however, yet more risks to grain production: 70 per cent of the world’s water use is in the irrigation of arable land. About 1000 tonnes of water is required to produce 1 tonne of grain. Much of this is drawn from underground aquifers 鈥� and these are close to depletion in parts of central Asia, the Middle East, north Africa, India, Pakistan and the US. Drill holes in excess of 1 kilometre deep are not uncommon, but to lift 1000 tonnes of water over that distance requires at least 9.8 gigajoules.
Grain is grown in soil, but 65 per cent of all soil on Earth shows signs of degradation such as erosion, desertification or salinisation. Over 300 million hectares of former agricultural land is now too degraded to produce food, and a further 10 million hectares become degraded or damaged every year.
“Peak soil” is long gone.
Essence of thought
Some perspective is needed on Gregory T. Huang’s position that the model developed by neuroscientist Karl Friston approaches a new and “grand theory” of brain function (31 May, p 30). The brain updating probabilities of what to expect from the world is certainly important 鈥� essentially it is the long-discussed phenomenon of learning. But this is frosting on the cake, not the cake itself.
The more basic topics not addressed by Friston include: how information is represented, how motivation can modify behaviour, how behaviour is elicited (decision-making), and the intimate nature of the expectancy and the learning process that he discusses. His model does not deal with these core issues, and so cannot be seen as an all-encompassing, E = mc2 -style summary of brain function.
His view of the plasticity of these core functions may be a useful part of a more general understanding, but the grand view is yet to be approached.
I have proposed that there is a largely common neural language across all brain systems 鈥� set out in “A study of the science of taste: On the origins and influence of the core ideas” (). It has been widely rejected by specialists in the fields of taste and other sensory systems, so it must be interesting.
Soaring depression
Is depression really undertreated (7 June, p 6)? Adult prescriptions for antidepressants in the US tripled between 1994 and 2005, to 118 million a year, according to the Centers for Disease Control and Prevention. As some antidepressants have been revealed as no more effective than a placebo 鈥� but with side effects 鈥� who is gaining from this frenzy of diagnosis?
The editor writes:
鈥� There is concern about overtreatment of those who are mildly depressed and solvent, and undertreatment of those who are seriously depressed and/or poor.
Out, dam spot!
Fred Pearce is right to worry about Chinese dams (7 June, p 8). On a visit to Qinghai prefecture in Tibet over 10 years ago, I saw widespread evidence of a casual approach to dam safety.
Some earthen irrigation dams in the highlands relied on weakly cohesive loam cores for their stability instead of clay.
I was told “this meets Chinese specifications”. The hushed-up 1975 Henan province multiple dam failure that Pearce mentions provides a good indication of the inadequate approach to integrated river-system planning and risk avoidance.
This casual approach to environmental planning has international implications. Where serious issues arise, even of public safety, they are routinely ignored in Chinese environmental impact assessments (EIAs) if the danger lies outside the province or 鈥� especially 鈥� outside China. Consider the dramatic and lethal effects of water starvation in Bangladesh and Assam, India, that will result from the damming and diversion of the waters of the Brahmaputra river by the , which is twice the size of the Three Gorges dam and also in an earthquake-prone zone. These effects are entirely absent from the original EIA.
The same process is now beginning in the Chinese headwaters of the Mekong. The perceived theft of water by these schemes risks retaliation, even direct action, by those who lose out downstream.
I fear that the era of water wars is arriving.
Policy wonky
While it is hard to argue with the principle behind your advocacy of more experimental research on proposed social policies (24 May, p 3) there are formidable practical obstacles. Rigorous research that delivers usable results within the short timescales demanded by policy-makers is hard to achieve.
I recently participated in a forum to map out future research into human-rights test cases in Australia. It brought together senior judges, lawyers, law academics and a handful of social science academics. The painful conclusion from a day of invigorating debate was that to properly assess the efficacy of test cases, scientific rigour demanded a long-term research programme.
Even in a system where judges cite earlier cases as precedents, it is fiendishly difficult to accurately gauge the effect of individual judgements on subsequent cases, never mind the broader social effects. Experimental design is made even more difficult by the fact that many so-called test cases are only identified in hindsight. Some of the lawyers in the room who lacked scientific training became very impatient with the methodological arguments, and the day ended on a much more sober note than it began.
While progress in science mostly proceeds in lollipop steps 鈥� heel to toe across the playground 鈥� policy-makers face enormous pressure to come up with the goods fast.
You're so special
Christine Kenneally proposes that it is language that sets us apart from the beasts (24 May, p 28). I find this odd, since a big-picture view of planet Earth suggests that it is the technical artefacts that we have developed 鈥� from stone axes through megacities to rocket ships 鈥� that make us outstandingly unique.
I propose a hypothesis, summed up by changing our name from Homo sapiens, “wise man”, to Homo mimicus, “mimicking man”. Many animals mimic each other’s behaviour, but we do it more often and with greater fidelity. Our compulsive copying encodes collective knowledge into our society, and it is really our society that possesses humanity’s “intelligence”.
Consider two islands, identical except that one has a population of highly intelligent but vain apes, while the other has a population of gregarious dimwits that love mimicking each other’s actions.
The “sapiens” are always inventing marvellous gadgets, but their vanity is such that they will never use another’s clever idea.
It is only by accident that a dimwit discovers that poking a honey-coated stick into a hollow log will pull out some delicious termites. But, seeing this, many mimicus copy it. Some of the copied actions improve the chances of survival of the sub-population performing them.
Which species is most likely to develop megacities or rocket ships? I’d back the dimwits.
From Will Barium
Since there is not much that is uniquely human 鈥� except art, cooking, religion, humour, sport and terrestrial dominance 鈥� shall we rename our species Pan sapiens?
Toronto, Canada
From Andrew Palfreyman
The assertion that humans are the only species capable of representational drawing is given the lie by the astounding video of an elephant painting a picture of an elephant at
San Jose, California, US