Meaning of life
Cosmologist Charley Lineweaver is trying to redraw the definition of life based on physical criteria that could take in hurricanes and stars (19 May, p 29).
Can you better define a life form by its waste? A hurricane does not produce waste, just “chewed up” material that comes out a different shape. I’m not a biologist, but everything I think of as terrestrial life produces a waste product.
This does, however, raise another question as to the definition of waste. Does a cell destroyed by a virus count as waste? Do carbon dioxide and other gases made by fire qualify?
From Matt Carmichael
Lineweaver points out that there is no satisfactory definition of life, a debate that is continued in Colin Barras’s article on seabed bugs (26 May, p 12). I see no reason why the whole universe cannot be considered a living thing. After all, even the vacuum of space is fizzing with subatomic activity as particles bubble in and out of existence.
This does not obviate the need for clear thinking about life, but shifts the task to distinguishing between different kinds of life. A living universe would contain a spectrum of life, with some forms closer than others to the DNA-based life that occupies biology.
This is also a more ecological view, which highlights the way life emerges out of the interconnectedness of things.
Leeds, West Yorkshire, UK
Love letter
In reifying evolution as a force or power that is separate from and even inimical to human beings and their values, Julian Savulescu and Anders Sandberg are talking as much nonsense as any fundamentalist theist who believes God created us as sinners and we must struggle to be good (12 May, p 28).
It is as silly to say that evolution only cares about the species reproducing itself as it is to say that humans are DNA’s way of making more DNA – but nowhere near as funny.
It is also laughable to suppose that giving those already holding power over others the additional power to administer love potions could engineer a happier world. To disabuse themselves of this fantastic notion, Savulescu and Sandberg need only watch Shakespeare’s A Midsummer Night’s Dream to see how wrong this could go, and how, in the absence of the engineers having a change of heart, it could easily stay that way.
Argue to the end
I read with interest the article exploring the evolutionary benefits to the group of being argumentative (26 May, p 32), but must confess I wondered why it needed stating. As someone with Asperger’s, it seems obvious to me that the vast majority of face-to-face communication is adversarial rather than inquisitorial.
However, having worked with people with Alzheimer’s, I have noted that they often retain their ability to argue robustly and persuasively – if inaccurately – after other abilities have gone. This supports the idea that their theory of mind fades more slowly than their executive functions, and is thus more fundamental.
Seeds of controversy
A key issue for the trial of genetically modified wheat at Rothamsted in the UK (12 May, p 5) is whether or not the modification will work. When we objected to the application for the trial, we pointed to evidence that aphids could quickly become habituated to the alarm pheromone engineered into the wheat to disrupt them, which is called (E)-b-farnesene (EBF), and which aphids release when attacked.
Research by Grit Kunert of the Max Planck Institute for Chemical Ecology in Jena, Germany, and colleagues concluded: “The lack of any defensive effect of EBF in this study might be due to the fact that natural enemy attack on individual aphids leads to a pulsed emission [of EBF], but the transgenic lines tested continuously produce EBF to which aphids may become habituated. Thus our results provide no support for the hypothesis that plant emission of… EBF is a direct defence against aphids ().
“However, there is scattered evidence… suggesting EBF emission might serve as an indirect defence by attracting aphid predators.”
Efficacy of the GM trait beyond a few aphid generations is surely an essential prerequisite before open-air testing. Trials in greenhouses would have established this.
Toby Bruce, of Rothamsted Research, writes:
• We agree the experiment might not work. This is why we do experiments – to test a hypothesis.
We have some reservations about Kunert’s experiment, which compared aphid settlement on GM plants and wild-type control plants in a container with mesh on top and very limited air movement. Under such conditions, the control plants would have been exposed to air containing EBF.
Our trial will test aphid settlement under real field conditions where there is air movement. It will also allow us to evaluate whether any of the aphid’s natural enemies are attracted by the wheat.
Seagrass solution
Might one way to protect threatened seagrass meadows (26 May, p 16) be to encourage commercial farming of them? Seagrass is used in artisan crafts, most familiarly twisted into cords to be woven into chair seats.
It could be used in other, similar crafts, and its long fibres should make it a good substitute for materials such as jute for making sacking and tote bags. Presumably it could also be used as a biomass fuel. Applications of this nature would free up land for food crops.
Fossil feud
Further to the row over the legality of auctioning a dinosaur skeleton in the US (26 May, p 4), one international convention of no small import is the .
It states that “cultural property” is that which, on religious or secular grounds, is specifically designated by a state as being important for archaeology, prehistory, history, literature, art or science. It includes objects of palaeontological interest as one of the categories.
The convention adds that the import, export or transfer of ownership of cultural property contrary to the convention by states party to it, shall be illicit. The US is party to the convention.
Transporting energy
I read with interest Peter Aldhous’s article on using spare energy from phone masts to power vaccine storage, in which he attributed to me the concern that hi-tech refrigerators might fail (26 May, p 22). This possibility should not be overlooked, but the more important point is that it is better to move the energy to the vaccine rather than the other way round.
What I found in my study in Kenya was that only 2.6 per cent of masts are within 1 kilometre of a health facility, as the criteria used in deciding the location of each are very different. It is better to “harvest” the energy from the mast in the form of ice and take it to where it is to be used.
I saw one site where vaccine was stored at a phone mast 1.7 kilometres from the clinic, but the refrigerator contained only spoilt vaccine because it was not convenient. Health workers preferred to keep vaccine in the clinic, using an expensive gas-powered refrigerator.
Modern morality
I don’t think morality has much to do with disgust, as suggested in your look at opposition to gay marriage (19 May, p 28). Disgust probably evolved from the advantage gained from avoiding sources of disease and toxins.
Morality probably evolved by group selection, which gave a survival advantage to groups of pre-humans who were able to avoid killing each other and focus instead on murdering competing tribes and other pre-human species. Modern morality probably evolved as an extension of this, to allow us to live in groups of unlimited size and largely made up of unrelated individuals.
As far as most of us are concerned – liberal and conservative alike, I suspect – the most important moral precepts are to avoid harming fellow humans and render aid to those in trouble. Everything else is either faith-based nonsense or an elaboration of these basic ideas.
Booze cruisers
I can bear witness to your report on drunken waxwings (2 June, p 17). Where I live, every year in late winter, when food is scarce, Bohemian waxwings (Bombycilla garrulus) fall out of trees. These birds flock in groups of 500 or more and cruise the city in search of fruit on crab apple and mountain ash trees. The fruit is invariably fermented by late winter. It is comical to see hundreds of staggering birds.
Spill the secret
I would like to suggest an alternative approach to the search for Starlite’s formula (12 May, p 40). It seems to me that listing the ingredients easily available to inventor Maurice Ward in the five to 10 years before his appearance on the TV show Tomorrrow’s World in March 1990 is essential.
I would guess he found this novel heat-resistant material accidentally, perhaps after a spillage, when the simplest way to dispose of a small mess is to wipe it up and throw the rag on an open fire. Suppose it wouldn’t burn?
In the dark?
There is a possibility that you do not consider in your report on suggestions that our cosmic neighbourhood may be dark matter-free (28 April, p 6). If most matter is in fact dark matter, organisms on Earth must be able to tolerate it continually passing through their bodies, and hence it must be made up of something such as weakly interacting massive particles (WIMPs).
Alternatively, by allowing the weak anthropic principle, such matter is not so benign. Maybe life, or evolution, on Earth cannot tolerate it, and we are just very lucky to be living in an extremely rare low-density region.
The editor writes:
• An interesting idea. The suggestion that our neck of the galaxy is dark matter-free is hotly disputed (2 June, p 7).
For the record
• In our look at creativity (26 May, p 37), we should have said that a majority of mathematicians have a single-digit Erdös number.