Doubly impenetrable
It may be of interest to Feedback’s readers to know that bwindi means impenetrable in the Lukiga language (27 May). In 1968 it seemed anomalous to have a forest in Uganda with the English word impenetrable as its name so we asked the local chiefs what the translation was. We adopted the term Bwindi Impenetrable Forest initially with the intention that “Impenetrable” would be dropped after a year or two when “Bwindi” was more recognised, but it appears to have stuck.
Cry foul for foulness?
It is not only satellite navigation that blanks out the island of Foulness, off the UK’s Essex coast (Feedback, 27 May). Searching for it on points you to a stretch of the Market Weighton Canal in east Yorkshire, and also to an area of the foreshore off Cromer, which is in Norfolk and also miles from the muddy Essex coast. However, Foulness is on the map itself if you know where to look, and it is indexed properly on and on the Ordnance Survey’s own site. So the sat-nav conspiracy may be more of a cock-up.
Biosafety first
I can see that a lot of the technology for “redesigning life”, or building biological devices, will benefit mankind greatly, but we are afraid of it getting into the wrong hands or getting out of hand (20 May, p 43). What is needed is some sort of “dead man’s switch” where the device will only operate, say, under the influence of a magnetic field, or in the presence of a certain chemical. We need to build this into the biobricks at a basic level so that it is omnipresent.
Cutting the cables
Feedback mentions a motorist seeing a sign saying “Beware, underground cables” and not knowing what to do about them (27 May).
Such signs are put there, in my native Australia, at least, because if a contractor or anyone else putting in underground services doesn’t know about the existence of cables, they are likely to dig right through them 鈥� an expensive and common problem. The notices are also found around rivers with the warning not to anchor there.
For the record
鈥� The reply to Simon Birnstingl’s question about chimp strength wrongly stated that it was written by the editor (3 June, p 22). It was, in fact, a quote from the news website of the journal Nature ().
鈥� In our article on nasty viruses circulating in Europe (6 May, p 6), we said that Ernest Gould worked at the University of Oxford. Professor Gould is actually at the Centre for Ecology & Hydrology in Oxford. We also stated that he was conducting a study “commissioned by the British government on the risk of insect-borne and other arthropod-borne viruses emerging in the UK”. While he does study emerging viruses, Professor Gould does not receive funding directly from government.
鈥� Jonathan Katz, whose work we reported in the 3 June issue (p 10), is at Washington University in St Louis, not the University of Washington, as we stated. We also omitted to say that Katz’s analysis can be found at .
Our knuckle-walking ancestors
Why assume the common ancestor of chimps and humans was a knuckle-walker (20 May, p 5)? It’s a fair bet it spent a lot of time up trees, but how it moved on the ground is anyone’s guess.
Knuckle-walking is a specialised mode of locomotion in its own right, not an intermediate stage between quadrupedality and bipedality 鈥� and in any case our more distant tree-dwelling ancestors were probably not quadrupeds. Of the modern apes, gibbons and orang-utans are bipedal on the rare occasions they come out of the trees. It is at least a possibility that the last common ancestor we shared with chimps spent a lot of time up trees, but walked bipedally. Our lineage would then have taken to spending increasing amounts of time on the ground and refined its bipedal mode of locomotion, while chimps 鈥� and gorillas, possibly independently 鈥� took to knuckle-walking.
One could speculate interminably on the reasons for choosing one or other of these ways of getting around. If nothing else, this would make sense of all those early fossils, such as Sahelanthropus tchadensis, which show signs of being bipedal 鈥� something which always seems to cause surprise, but perhaps shouldn’t.
Reflection on mirror neurons
During the REM sleep state (believed to be linked to dreaming), neurons in our visual cortex fire, as if we really see something. Such activity is thought to generate what we see in dreams, but do we call these neurons dream neurons? No, because the neurons there only provide us with the visual part of the dreaming experience and are in no way central to the dreaming process.
Kudos is due to the researchers who discovered the existence of the mirror neuron system 鈥� a group of neurons that control voluntary movements, but also fire when the individual observes such movements. Giving such a name to these neurons of the premotor cortex seems premature, however (13 May, p 48). Those neurons may play no more role than providing us with similar proprioception feelings as we actually move. The key part may lie somewhere else. Indeed the ability of people with autism to suppress mu-wave activity when they move their own hands suggests that the mirror neurons are functional.
Reduction, rather than absence, of mirror neurons is unlikely to be responsible for the total absence of mirror neuron activities. A better explanation could be a lack of stimuli from the mirror neuron system, the location of which is still elusive.
Do gravitational waves exist?
The second paragraph of the story on gravitational waves begins: “Gravitational waves are set off by extreme events, such as supernova explosions, but they are weak and notoriously difficult to detect” (27 May, p 10). This implies that gravitational waves have actually been detected, albeit with great difficulty. As far as I am aware this is not the case.
My letter is not written in the spirit of semantic hair-splitting. It seems to me that the existence or otherwise of gravitational waves is a vital issue for our understanding of the universe and there are a number of projects, employing cutting edge science, in development to try and settle this issue. Implying that this has already been done is not going to help these projects, nor will it advance our knowledge of the universe.
We have named gravitational waves correctly
Yes, we have no bananas
I read with interest the warnings of a future without bananas due to pandemics of diseases such as black sigatoka fungus (13 May, p 5). In Australia we are in that new world already. Cyclone Larry destroyed all the crops in our main banana-growing regions, and we cannot import bananas due to the diseases mentioned. With supply extremely short, prices have jumped from about A$3 per kilo to A$12, and quality is reduced. Most people now only buy one or two bananas at a time, and I have not bought any for five weeks. It has been hard, but Australia is now well prepared for the complete demise of our favourite fruit.
Tidal stretch
I can see that the rapid disintegration of ice caps and glaciers might cause major, localised geological stresses (27 May, p 32). But I find it hard to believe that the same would be true for moving masses of water due to global warming. Twice every day, the tides cause global rises and falls in sea level of anything up to 15 metres. These undoubtedly knead the Earth’s crust. By comparison, a storm surge caused by a 50 millibar drop in atmospheric pressure in a deep Atlantic low corresponds with a short-lived rise in sea level of only about 50 centimetres.
Why nuns live longer
Several of your articles on how to live to 100 mention that more nuns live to this age than non-nuns (3 June, p 36). This was attributed to clean living and staying active, but another significant difference between this group and others was not addressed. Nuns take a vow of chastity and do not, therefore, have to the deal with the physiological stress of pregnancy, birth and nursing, which could affect lifespan. What effect does reproduction have on a woman’s longevity?
Origins of autism
Exposure to heavy metals is only one possible explanation for the elevated levels of urinary porphyrins found in French children with autism (27 May, p 21). Many other toxic chemicals, such as hexacholorobenzene, drugs such as anabolic steroids, and even chronic exposure to low levels of carbon monoxide (CO) have been found to increase urinary porphyrins, in particular coproporphyrins.
The possible role of CO in autism is particularly significant, since CO poisoning is known to cause similar chronic symptoms, and there is strong interest in hyperbaric oxygen therapy, the gold standard of treatment for CO poisoning, as a treatment for autism.
The end of physics?
Some of the ideas in Marcus Chown’s article about “extra” dimensions and warped brane universes sounded awfully familiar (20 May, p 34). It wasn’t long ago that physicists were convinced that light travelled in “ether”. Now they are convinced that gravity travels in the “bulk”.
Bulk or ether, what’s the difference? It seems to me that they have pushed the ether problem further downstream into the realm of the uninvestigatable and unquantifiable. Now it has got to the point where physicists are talking about space-time that is even more compact than previously thought possible. Why? Why are we digging so deep? Could it be that we just don’t have the mathematics to accurately describe the universe?
Personally, I’m quite content with the idea that Newtonian mechanics and relativity don’t mesh well. Why should they? The idea of a unification theory is just that, an idea. Even if we discovered a grand unifying theory tomorrow it’s not going to get me to work any faster. But little by little, fewer and fewer people will be able to understand the entire picture. We are drowning in theory now.
I think that unless someone sits down, takes a deep breath and starts with a clean sheet of paper, the physics community is going to suffer from its own China syndrome and collapse in on itself. What we need is a white paper on physics. Let’s start asking tough questions: should we even be expending brain power on such “virtual” problems, or should we shift our collective knowledge to start solving the more real problems that the world is facing right now. What good is a unifying theory if all we do is to end up killing ourselves in the process?
Eat dirt
You say it that it is not uncommon for people in Zimbabwe to eat soil as an instinctive way of redressing dietary deficiencies in trace minerals, and that the soil also contains a treatment for diarrhoea (27 May, p 54). Given that soil bacteria from South Africa have been found to contain an antibiotic effective in eliminating two common hospital superbugs, perhaps the soil also provides such consumers with antibiotic protection from other bacteria (20 May, p 22).
It seems as though the traditions of non-western societies may provide directional pointers for our sometimes blinkered, western scientific hypotheses. This may bring cheaper and faster routes to improving our knowledge bases.
Forest successes
Your article on our report Status of Tropical Forest Management 2005 says, “20 years of international pledges and environmental campaigning have barely improved the state of the world’s tropical forests”. But the article fails to recognise that it is partly because of the low level of financial assistance provided by the international community that progress towards sustainable forest management has been less than needed and hoped for (3 June, p 12).
That few of the world’s tropical forests are under good management was known in 1988, when we did our first survey. At that time less than 1 million hectares was thought to be sustainably managed. The most recent survey found 25.2 million hectares 鈥� 7.1 per cent of the total permanent forest estate (PFE) available for timber production 鈥� now under sustainable management. Rather than being “embarrassing”, this finding is cause for hope, because it shows that progress is being made, albeit at a slower rate than we would wish. Many of these forests are being managed by indigenous and other local communities, who are deriving significant economic benefits by doing so 鈥� another essential element for the uptake of sustainable forest management.
Perhaps of greater concern to the international community should be the apparent lack of management, and therefore protection, being afforded forest reserved for conservation. We found evidence of good management in only 11.2 million hectares of 451 million hectares of reserved PFE.
Your article implies that the international community is wasting its money trying to make tropical forestry more sustainable. However, we estimate that no more than $50 million per year is being invested by donors in tropical forest management, which equates to less than 10 cents per hectare of tropical PFE and not much more than a dollar per hectare of sustainably managed forest. Given this, the level of progress being made in applying sustainable forest management seems impressive, and suggests that more support from countries, organisations like ITTO, the private sector and the non-governmental community could lead to a more rapid expansion of the area of well-managed forests in the future.