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Credible theories
OPINION LETTERS Local ecology From Chris Smuts-Kennedy, Biodiversity Manager, Maungatautari Ecological Island Trust Garry Hamilton’s argument that invasive species could be beneficial to ecosystems pertains more to continents than to islands (15 January, p 34). The continuing damage to many island ecosystems by human-mediated invaders is enormous. However, effective biosecurity measures can prevent invasions, and this is being successfully achieved all over the world – even in blocks of mainland habitat such as New Zealand’s forested Maungatautari mountain. A decade ago, only 12 native forest bird species survived there. But since the mountain has been surrounded by a 47-kilometre pest-proof fence, a dozen alien mammal species have been eradicated and the native bird population has been rebuilt to over 30 species. Sadly, several species once present are now totally extinct, but it is hoped that lizards, tuatara, frogs, bats and fish will be reintroduced.
The long-term sustainability of such management seems irrelevant to me: it would be an abdication of human responsibility not to save and restore unique species and ecosystems that would otherwise be lost. On continental scales we might have to remain interested observers, but on smaller scales we may be able to intervene positively. Cambridge, New Zealand
Economic evolution
Credible theories From Richard Durrant I must object to the idea put forward in your feature on climate models that “it is the differences between [climate] models that help to ensure predictions are in the right ball park” (15 January, p 38). Splitting the difference cannot be relied on to give you the right answer. Theories must stand or fall on whether they can produce credible predictions. There is a book in my local library, published several years ago, which is full of equations concerning US stock prices. Its overall prediction was that the Dow Jones index
Enigma Number 1633
Same perfect square Richard England Harry, Tom and I were each looking to find two 2-digit positive integers which each were the product of two primes and whose difference was also the product of two primes, the six primes all being different. We each found a different valid solution; in each solution the sum of the two integers was a perfect square. For Harry and Tom it was the same perfect square. What were my two integers? WIN £15 will be awarded to the sender of the first correct answer opened on Wednesday 23 March. The Editor’s decision is final. Please send entries to Enigma 1633, New Scientist, Lacon House, 84 Theobald’s Road, London WC1X 8NS, or to [email protected] (please include your postal address). Answer to 1627 THEBES = 542823 The winner Mike Waterman, Camberley, Surrey, UK
28 | NewScientist | 12 February 2011
would rise to 60,000 points. In the same library there is also a book called The Crash of 2010. We could have avoided a lot of financial pain if we had listened to someone with unconventional ideas that did not suit the establishment. St Albans, Hertfordshire, UK
Ape versus dog From Paul Kail You say that Chaser the border collie knows the names of 1022 items, more than any other animal (25 December 2010, p 8). Koko, a gorilla first studied at the University of Stanford, California, reportedly understands twice as many, and can actually use over 1000. Some humans can use even more. Prague, Czech Republic
Faecal phages
From Charlie Robinson There are many interesting parallels between the global financial system and natural ecosystems (22 January, p 6). It is not entirely surprising, given that financial institutions are able to pass on the information which encodes their operations, are subject to mutation and exist in a milieu which imposes selection pressures – all characteristics required for natural selection to occur. It seems to me that the activities of financial institutions may even be determined more by Darwinian selection processes than by the people who are nominally in charge of them – though perhaps a degree of Lamarckism could be conceded. However, as these institutions can exchange information in many directions, rather than simply from one generation to the next, perhaps the world of microbial ecosystems would prove a better comparison. The opportunity to compare bankers to bacteria obviously has nothing to do with the appeal of this idea. Hove, East Sussex, UK
From Ivan Erill, University of Maryland, Baltimore County Given that “poo is a zoo”, it seems surprising that the report on the use of faecal transplantation to combat Clostridium difficile infections left out one of the most abundant members of intestinal fauna: the viruses known as bacteriophages (18 December 2010, p 36). These viruses infect bacteria, and were in fact first identified in stool samples. It seems at least plausible that part of any beneficial effect of faecal transplants may come from phages in the transplanted stool destroying C. difficile, rather than from direct competition by colonising bacteria. Of course, after C. difficile has been eradicated by the phages, colonising bacteria could contribute to restoring normal intestinal fauna. Baltimore, Maryland, US
Seeing is believing From Linda Shields, Professor of Paediatric and Child Health Nursing, Curtin University We should not be surprised by the strength of the antiimmunisation lobby (15 January, p 46). In rich nations, the majority of the population has never seen the diseases that we recommend parents vaccinate their children
The long-term sustainability of such management seems irrelevant to me: it would be an abdication of human responsibility not to save and restore unique species and ecosystems that would otherwise be lost. On continental scales we might have to remain interested observers, but on smaller scales we may be able to intervene positively. Cambridge, New Zealand
Economic evolution
Credible theories From Richard Durrant I must object to the idea put forward in your feature on climate models that “it is the differences between [climate] models that help to ensure predictions are in the right ball park” (15 January, p 38). Splitting the difference cannot be relied on to give you the right answer. Theories must stand or fall on whether they can produce credible predictions. There is a book in my local library, published several years ago, which is full of equations concerning US stock prices. Its overall prediction was that the Dow Jones index
Enigma Number 1633
Same perfect square Richard England Harry, Tom and I were each looking to find two 2-digit positive integers which each were the product of two primes and whose difference was also the product of two primes, the six primes all being different. We each found a different valid solution; in each solution the sum of the two integers was a perfect square. For Harry and Tom it was the same perfect square. What were my two integers? WIN £15 will be awarded to the sender of the first correct answer opened on Wednesday 23 March. The Editor’s decision is final. Please send entries to Enigma 1633, New Scientist, Lacon House, 84 Theobald’s Road, London WC1X 8NS, or to [email protected] (please include your postal address). Answer to 1627 THEBES = 542823 The winner Mike Waterman, Camberley, Surrey, UK
28 | NewScientist | 12 February 2011
would rise to 60,000 points. In the same library there is also a book called The Crash of 2010. We could have avoided a lot of financial pain if we had listened to someone with unconventional ideas that did not suit the establishment. St Albans, Hertfordshire, UK
Ape versus dog From Paul Kail You say that Chaser the border collie knows the names of 1022 items, more than any other animal (25 December 2010, p 8). Koko, a gorilla first studied at the University of Stanford, California, reportedly understands twice as many, and can actually use over 1000. Some humans can use even more. Prague, Czech Republic
Faecal phages
From Charlie Robinson There are many interesting parallels between the global financial system and natural ecosystems (22 January, p 6). It is not entirely surprising, given that financial institutions are able to pass on the information which encodes their operations, are subject to mutation and exist in a milieu which imposes selection pressures – all characteristics required for natural selection to occur. It seems to me that the activities of financial institutions may even be determined more by Darwinian selection processes than by the people who are nominally in charge of them – though perhaps a degree of Lamarckism could be conceded. However, as these institutions can exchange information in many directions, rather than simply from one generation to the next, perhaps the world of microbial ecosystems would prove a better comparison. The opportunity to compare bankers to bacteria obviously has nothing to do with the appeal of this idea. Hove, East Sussex, UK
From Ivan Erill, University of Maryland, Baltimore County Given that “poo is a zoo”, it seems surprising that the report on the use of faecal transplantation to combat Clostridium difficile infections left out one of the most abundant members of intestinal fauna: the viruses known as bacteriophages (18 December 2010, p 36). These viruses infect bacteria, and were in fact first identified in stool samples. It seems at least plausible that part of any beneficial effect of faecal transplants may come from phages in the transplanted stool destroying C. difficile, rather than from direct competition by colonising bacteria. Of course, after C. difficile has been eradicated by the phages, colonising bacteria could contribute to restoring normal intestinal fauna. Baltimore, Maryland, US
Seeing is believing From Linda Shields, Professor of Paediatric and Child Health Nursing, Curtin University We should not be surprised by the strength of the antiimmunisation lobby (15 January, p 46). In rich nations, the majority of the population has never seen the diseases that we recommend parents vaccinate their children