If fish could fly
The top-down theory of the evolution of flight due to the impetus of gravity, outlined by Alan Feduccia (28 April, p 28), is supported by the fact that true flight has never evolved in animals living in water, where the surface is flat.
Flying fish do not actually fly, but rather use the aerodynamic lifting force known as the ground effect to help keep them airborne, and simply glide after they leave the water under conventional swimming thrust, most likely to escape predators. advantage for fish that could truly fly but, as Feduccia suggests, if it could happen it would have evolved by now.
Selfish gene?
The theories to explain the negative correlation between wealth and empathy that you described are plausible (21 April, p 52), but I would like to offer another possible causal connection.
People who care less about others are more likely to see life as a rat race, and more likely to push their way ahead. If they prosper, their children may inherit similar attitudes, whether by genetics, upbringing or a mixture of both. The result would be less empathy among the wealthy.
Space mining
The issue of who can own asteroids and their associated mining rights needs settling (21 April, p 48). Returns for mining companies need to be sufficient, but the ordinary people must not be forgotten.
I suggest asteroid mining rights be held in trust by the United Nations for the world population, with licences granted by this trust to those wishing to exploit such resources. This would ensure the additional cost of exploitation is not punitive but the general population benefits.
The editor writes:
• The relevant legal document is the UN’s , but there is ambiguity: no one is allowed to claim sovereignty of anything in outer space, but there is nothing to say you can’t profit from it…
Silt crucial
Possibly the main impact of China’s plans to dam the Brahmaputra river (28 April, p 8) will be the restriction on the supply of sediment to the Ganges delta. This will greatly increase the rate of erosion and loss of land in the delta, mainly in Bangladesh.
due to the weight of sediment already in place. If insufficient sediment is deposited to make up for this height loss, larger areas may well become subject to longer periods of flooding.
Look at me
Psychologist Jeffrey Arnett’s observation that young people are volunteering in greater numbers does not necessarily contradict the theory that today’s youth are more narcissistic than previous generations (28 April, p 44). In a culture of social networking, drumming up charity donations for running a marathon via email or Facebook is an effective way to garner attention and admiration from peers, who would seem churlish if they voiced suspicions of self-promotion.
That is not to say previous generations are innocent, but social networking may have amplified this behaviour in the current generation. Since some older people have also discovered their inner narcissist in this way, perhaps social media simply legitimise and encourage deep-seated instincts.
The human animal
In trying to pin down common characteristics that set us apart from other animals (21 April, p 38), you forgot perhaps the most distinguishing: humans can thwart their basic mammalian needs because of cultural ideology. Some can deny their babies breastfeeding, touch, responsiveness and even play, creating a different nature from their evolutionary heritage.
From Mike Paterson
How about self-justification as a universal characteristic of humans? I would suggest it underlies some of the traits proposed: gossip, the impulse to legislate and, perhaps, science.
Kingston, Ontario, Canada
Social media
Jim Giles describes the finding that conscientious people use more colons in their tweets as an “odd surprise” (28 April, p 40). But is it?
Colons are refined and nuanced appendages to the ordinary, run-of-the-mill lexicon of grammar; exactly the sort of thing that conscientious people, well attuned to the niceties of protocol and the finer points of obligation, might be expected to observe.
From Nick Beale
There are ways to foil Facebook algorithms that profile you without your knowledge: ensure you have an eclectic group of friends who live further than 40 kilometres away; talk to people who went to different universities; enjoy being with those of different sexual orientation; make friends that none of your other friends know; try to be extrovert and agreeable, or conscientious and open.
Facebook can profile predictable personalities, it cannot fathom those who are interesting.
Newcastle upon Tyne, UK
Limited diet
Helen Knight writes that “various studies have shown that people with restricted choice – or none at all – often feel happier with a given outcome than those with more freedom” (14 April, p 36).
It seems that authors knew it long ago. In Kenneth Roberts’s book Northwest Passage, published in 1937, we find this discussion of choice: “‘Jesse,’ I said, ‘don’t you get sick of sausage and corn meal?’ ‘No,’ Jesse said. ‘No. If there ain’t nothing to eat but sausage and corn meal, you like it. If you had to choose between sausage and corn meal and sausage and beans, you’d hate both of em.'”
Earlier and earlier
Further to Stuart Goldman’s letter on driverless cars (28 April, p 31). I don’t suppose German author Erich Kästner was the first, but he described them in his 1931 story The 35th of May.
Also mentioned were mobile phones and moving walkways, along with portals to alternative realities at the back of a wardrobe – well before C.S.Lewis.
Sleeper cells
I read with interest your article on so-called sleeper cells – bacteria that become dormant to survive antibiotics, reactivating when the threat has passed (31 March, p 40). From experience, I am sure Burkholderia pseudomallei (previously called Pseudomonas pseudomallei), which causes melioidosis, should be on the list of such organisms.
I got this infection in 2008 in Borneo. It manifested as pneumonia and was treated with two weeks of intravenous antibiotics. One week after finishing the treatment, and while on a preventative course of ampicillin, I had a recurrence.
This was frightening, given the sledgehammers that were used against the original infection, and I could not understand it until I read your article.
Faith and reason
Your story on how thinking analytically can dim religious belief (5 May, p 14) fitted perfectly with members of the church I used to belong to.
When pressed to really think about what they professed to believe in, most people preferred not to do so. The few who opted to analyse their beliefs, like me, underwent major changes in their faith.
Quick slime
When I read about the experiment in which slime mould spread patterns were shown to mimic road networks in the US (24 March, p 23), I thought it must have been carried out on maps.
Then I realised that many US roads have yellow lines down the middle and that I had been incorrect in believing them to be lane markers… they must be trails of Physarum polycephalum.
Dark difficulty
It was intriguing to read that experiments suggest dark matter may not be present in our part of the galaxy (28 April, p 6), whereas the majority opinion is that it should be.
More intriguing for those of us with a sceptical nature was the statement by Rory Smith of the University of ConcepciÓn in Chile that dark matter is still needed because “it explains an enormous number of things famously well”.
This begs the question of whether something we can’t detect even when it should be detectable is an explanation at all. It seems more like proponents of the standard model of particle physics have chosen to give a big problem a trendy name in order to brush it aside.
That there is 83 per cent less detectable matter in the universe than the standard model demands cannot be explained away as a minor irritant called “dark matter” any more than losing both arms and legs to an opposing swordsman could be considered to be “only a flesh wound”.
Growing resistance
Alasdair Cook’s letter (28 April, p 30), quoting a 1948 report from the Veterinary Record on a diminution in the efficacy of penicillin, rang a very loud bell.
In 1823, doctor John Elliotson wrote in : “When we first had sulphate of quinine [the first synthetic antimalarial drug] I was generally able to cure the disease with two or three grains, two or three times a day but that does not generally happen to me now.” , there were reports that the current most effective antimalarial – artemisinin – is losing its potency in some parts of the world, largely due to inappropriate use of the drug. Will we ever learn?