Infectious theory
It is good to see the theory that the transmissible spongiform encephalopathies (TSEs) could be caused by virus-like particles, not prions, being reported (27 October, p 10). Since Stanley Prusiner stated his prion hypothesis in 1982 much work by the “virus camp” has been ignored in favour of prions.
Although the argument is by no means won, it seems that parity is being restored in the debate. The sooner the mystery of the TSEs is revealed, the sooner scientists can begin to investigate possible cures.
Nowhere to go but…
Your article on Pangaea, the comeback, (20 October, p 36) was fascinating. Roy Livermore commented “I don’t believe Antarctica is going to stay at the pole… I want it to come north.” That does seems the most likely direction.
For the record
鈥� Paul Mellars is professor of archaeology at Cambridge, not at the other place we mentioned in the article Going global (27 October, p 36).
Sinister smiles
In response to the letter from Nicki Parsons (20 October, p 27), I would wager that she, like myself, is left-handed. When I concentrate on what my eyes are doing when reading printed materials, I am aware that they first go to the right of the page and I can detect myself correcting and then starting from the left. I’ve checked with a few other “lefties” and they have discovered the same.
Hence, when viewing the chimeric faces, we have already subconsciously begun a scan from right to left and therefore find the top picture to look happier, at least initially.
Beavers contained
The published version of my letter (22 September, p 24) omitted several important points, including one made subsequently by Paul Ramsay (20 October, p 26), that exemptions to allow control of beavers had to be granted in some countries including Latvia and Estonia. I also showed the tiny impact that removing protection made. Numbers soared in Estonia from around 1000 in 1985 to more than 10,000 15 years later, despite shooting and trapping in that time. And there are more beavers than there is demand for hunting. Selectively trapping or shooting problem animals is not the answer 鈥� others simply move in. I doubt Latvia could afford to compensate for damage when there are about 80,000 beavers present, or six active pairs per 10 square kilometres. And compensation payments are always tricky.
Yes, landowners and farmers are the primary stakeholders and they have the right to use their land (responsibly) without impediment. Beavers would reduce their options.
I have no problem with anyone keeping beavers humanely in containment, as long as great care is taken to prevent escape and responsibility for any escapes is laid at their door. That is also the best way for visitors to view shy animals. Tourists, and locals, already derive pleasure from seeing wildlife such as the red squirrel and golden eagle in Scotland. How many catch a glimpse of a capercaillie or a pine marten? In my view, conserving what we have should be the priority.
Billet doux
Robert Heath’s letter comparing the sugar content of foods in the US with those in the UK made interesting reading (27 October, p 26). A comparison between the UK and France might show a similar disparity. As a resident of France for more than 15 years, I was shocked to find how difficult it is to buy ready-prepared foods in the UK that do not contain sugar. I have just checked the French ready soups in my pantry: out of six cartons, only one contains sugar. In the UK I had to scour a large supermarket for soup for my diabetic mother. Out of the dozens I could find only one without added sugar.
The story is similar for items such as yoghurt. Here I have a large range of no-added-sugar fruit yoghurts. Bread does not contain sugar (except for brioche). Local children find British baked beans utterly disgusting 鈥� they’re much too sweet. I now reduce the sugar content of any recipe in a UK cookbook by about half.
Has anyone done a study comparing average sugar intake with average corpulence by country?
Near-perfect model
Christopher Mead refers to a story by Jorge Luis Borges about a map at 1:1 scale (13 October, p 24). A similar map appears in by Lewis Carroll, published in 1893:
“What do you consider the largest map that would be really useful?”
“About six inches to the mile.”
“Only six inches!” exclaimed Mein Herr. “We very soon got to six yards to the mile. Then we tried a hundred yards to the mile. And then came the grandest idea of all! We actually made a map of the country, on the scale of a mile to the mile!”
“It has never been spread out, yet,” said Mein Herr: “the farmers objected: they said it would cover the whole country, and shut out the sunlight! So we now use the country itself, as its own map, and I assure you it does nearly as well.”
It is a great story when talking about models and how to use them. I wonder whether anyone knows an even earlier version.
Now you see it
I had always believed that it was impossible, when looking at the “image-flip” picture of two faces and a vase, to see the faces and the vase simultaneously (20 October, p 10). I resolved to try again, using your picture. It took me about 10 seconds to succeed the first time, holding the picture about a foot from my face, and it took less time subsequently.
One achieves and can sustain a kind of letting-go, similar to that required when looking at Magic Eye 3D pictures: neither the two-faces aspect nor the vase is the focus of attention, though there is full awareness of both. If MRI imaging is used to examine the neurology of image-flipping, perhaps it should also be used to examine the neurology of this state.
The brain can “consciously perceive both versions simultaneously” if it imagines twins pressing their faces against a vase. It would be interesting to see a photo of twins doing that.
Calgary, Alberta, Canada
Continental shift
Caroline Williams and Ted Nield, discussing cyclic supercontinents, talk about the Earth’s crust being continually created and destroyed (20 October, p 36). But what about the continents themselves?
As I understand it, they are primarily made of granite, which is less dense than crustal rock, and hence floats on it. Is this continental material also being created and destroyed? Presumably bits of it get lost at the edges when continental fragments split and rejoin.
Will the Indian subcontinent, which had much of its lower levels melted away during the splitting up of Gondwanaland (20 October, p 23) acquire new basal material over time, or will it forever remain a rootless drifter? And if no new fragments are being created, does that mean the total area of the continents will gradually shrink?
After pointing out uncertainties over which of the theories of supercontinent formation 250 million years hence may prove to be more correct, the authors go on to state that humans won’t be around to see it. Human beings might indeed be extinct by then. Or they may have evolved into beings that are quite different and unrecognisable as us. Or they may have brought plate tectonics to a halt, or even colonised the universe and turned Earth into a plate-tectonics reserve…
Kanata, Ontario, Canada
Thank you, Igor
How refreshing to see an article praising the virtues of a good lab technician (6 October, p 62, UK edition only). As someone who has neither the patience nor the dexterity to do the job, I have always been absolutely dependent on the skills, advice and thorough notes and observations of the various superb technicians that I have worked with.
It is time to revisit the career structures and necessary qualifications of those who choose this path over the “academic” route and are good at it, to allow suitable people to make valuable contributions in the laboratory. As Katharine Comisso says, one quality must be “an enthusiasm for science”. Many “professions” are now closed to those who are unable to obtain a degree, or choose not to.
Our explosive start
Dan Jones asks “why did humans leave Africa when they did…” (27 October, p 36). I am surprised he did not mention the idea that the supervolcanic explosion of Toba on Sumatra about 70,000 years ago caused a bottleneck in the evolution of all species, especially Homo sapiens.
For at least six years, there was a “volcanic winter” that must have had a profound effect on our ancestors, probably forcing major lifestyle changes. It is surely not a coincidence that within 5000 years our species migrated out of Africa. Species tend to react to environmental factors; perhaps we owe our developmental spurt and exploratory instinct to the Toba catastrophe.
Innate bile
Philip Lieberman has been stewing in his bile over Noam Chomsky for so long that he sees signs of a Chomskyan conspiracy everywhere, including in my book The Stuff of Thought (6 October, p 57). I make a few mentions of Chomsky, half of them critical.
Lieberman attributes to me the belief that “children do not learn the particular syntactic processes that characterise the grammar of their native language. Instead, the rules of syntax for every language on Earth lie dormant in their brains.” Nothing in my book comes close to this bizarre hypothesis. Even more remarkably, he writes: “According to Pinker, we don’t learn the meanings of particular words.” I devote the better part of a chapter to arguing against this theory.
As for Lieberman’s argument that if children had any basic concepts then “genetic variation would ensure that some people lacked a concept or two”, this only follows if every concept is installed by a single gene, a one-gene-one-trait theory of development that biologists rejected long ago. (The second metacarpal is a basic component of the hand, but we don’t expect to find a mutant who lacks only a second metacarpal.)
People may indeed vary in terms of how they deploy concepts such as causation, space and intentionality, but such variation surely depends on many genes, not one apiece.
There are no green cars
The Volkswagen BlueMotion Polo advert in New 杏吧原创 (27 October, p 28) implies that this car is environmentally friendly.
It is economical relative to other cars, but driving it does not “prevent” carbon pollution as is claimed. Driving this car for 10,000 kilometres still leads to the emission of 1 tonne of carbon dioxide. This type of advert allows us to kid ourselves that we can carry on with our CO2-emitting lifestyles. In reality we are going to have to consume and travel much, much less than we do now.
Unmanageable seas
Bj酶rn Lomborg’s opinions are a useful irritant questioning mainstream opinion, but might he not be over-optimistic in arguing that a sea level rise of 30 centimetres is manageable (27 October, p 54)? New research almost invariably seems to report that climate change is faster, or is likely to be more extreme, than previous orthodoxy suggested 鈥� for instance, recent findings on CO2 absorption in the Atlantic.
Does his argument hold true if the forecast sea level increase proves to be underestimated by a factor of, say, 10? See, for example, James Hansen’s warnings (28 July, p 30). Thermal expansion ensures that further rises keep coming, even if atmospheric temperatures can be stabilised.
I am sure Lomborg is right to press for greater long-term research into alternative energy sources, but even with a tenfold improvement in efficiency are there sufficient raw materials to provide enough solar power to supply a significant proportion of world electricity needs?
Elementary, Watson
James Watson’s remarks about the intelligence of Africans were even more outrageous than you have noticed (27 October, p 24) because of their context. He was apparently speaking in response to the suggestion that African nations were particularly difficult 鈥� presumably for the west 鈥� to deal with.
Watson ignored the obvious possibility that any such difficulty might result from the fact that those western nations had, for a long time, systematically plundered the whole continent, making it very hard for independent nations to get started there at all.
Instead, he simply attributed the trouble to Africans being naturally stupid, claiming scientific authority. Of course you are right to note the hollowness of this last claim, but it is actually a minor part of the offence.
James Watson’s claims on race and intelligence have of course received wide coverage, but in the popular press there has been a consistent lack of analysis of the scientific basis of such statements.
I cannot imagine that readers of this disappointing coverage are left thinking anything other than that sub-Saharan Africans have been proven by scientists to be intellectually less able than others.
The scientific arguments against such a claim are extensive, but sometimes difficult to follow. It is the responsibility of scientists to present them to the public in a simplified form, if required, for completeness of the argument.
Issues that I feel have not been sufficiently tackled in the public domain include the inherent problems of defining and measuring intelligence and the difficulty of separating environmental from genetic causes of observations. Then there are the problems of experimental designs being linked to the hypothesis to be tested: are the test designs based on a starting assumption of race equality? If scientists are honest and open about these and other issues in a comprehensible format, then the public will be in a better position to make a judgement.
Skin colour and race are not synonymous and should not be treated as such. A race is a group of people related by common descent or heredity. While we may not apply this to dogs we certainly do differentiate them by breed. Somehow this doesn’t seem quite fitting as a label for different humans.