Green umbrella
Stephen Battersby attributes increased bogginess in Europe to the removal of forests thousands of years ago (11 January, p 46). He argues that reduced evapotranspiration, whereby trees take water from the ground and return it to the air via their leaves, led to wetter soils and bogs.
This is a well-recognised phenomenon, but may be only part of the reason. Another process at work is interception, when rain sticks to foliage and evaporates. Remove the trees and the soil gets wetter.
This is happening in parts of semi-arid Australia. Removal of natural scrub over many decades has allowed more water into the soil, raising the water table. Unfortunately, the subsoil is heavily saline so the rising water brings salt to the surface and remaining vegetation dies.
Christchurch, New Zealand
For the record
鈥� Sugar-free. Researchers at the Indian Institute of Science used a labelled amino acid, not a sugar, to study the relationship between ants and the Humboldtia brunonis tree (15 February, p 18).
鈥� In our look at robot romance, we wove in an inaccuracy. Dan O’Hara at Birmingham City University, UK, was a consultant for a company that designed the online bot Weavr, rather than its designer (15 February, p 29).
鈥� Double ouch in our pain genetics story (8 February, p 12). It was the TRPA1 promoter gene, not TrypA1, and this was also the only one of the nine genes identified that showed the correlation between higher pain sensitivity and higher methylation level.
Sup this
If you are struggling to find a non-alcoholic drink for adults to savour (1 February, p 32), I highly recommend soda, lime and bitters. Tasty and not too sweet.
Bronte, New South Wales, Australia
Going cheep
Kate Douglas looks at how a bird that was bred for its plumage came to sing intricate melodies composed of many phrases (8 February, p 36). For me, the most plausible explanation is that, intentionally or not, the Bengalese finch was bred for song as well.
Breeders probably weren’t selecting for plumage alone, but for overall aesthetics. This would involve subjective judgement of multiple traits. Even if a breeder intended to select solely on plumage, better singers would still have an advantage over birds with comparable visual appeal. And note that unlike selection for weight, which might plausibly be done in hatchlings, selection for plumage would involve “breeding plumage”, by which time the birds would also be singing.
Ann Arbor, Michigan, US
Back to Africa
There is some historical evidence to support the theory that European DNA made its way into southern African tribes at the time of the Roman Empire. Around 450 BC, ancient Greek historian Herodotus wrote in the Histories that King Necho of Egypt ordered a ship to sail around Africa, and that it returned two years later.
Herodotus was sceptical about the story’s claim that when the ship was off the southern tip of Africa, the sun shone from the north. Inadvertently, this scepticism provided strong supporting evidence that the full two-year voyage did happen. It would strain credulity to suggest the sailors remained celibate for the duration.
Dublin, Ireland
Back to Africa
With hindsight, it seems obvious that there might be Eurasian genes in populations in the south of Africa once thought to be genetically isolated (8 February, p 10). The idea of these people being totally isolated before European contact was too parochial. Three thousand years ago, advanced civilisations had been flourishing in the Middle East for millennia, and although the Atlantic was not accessible to them, coastal travel along the east of Africa seems likely.
Certainly by 900 years ago, with the Crusades under way and spices being traded from India, there must have been a lot of travel down the east coast of Africa, and it is not surprising that Middle Eastern genes might be found throughout.
Toronto, Canada
Batting for bats
As a former bat ecologist I thought your article on diseases carried by bats (8 February, p 44) unnecessarily demonised these animals, which already get a bad press. What next? “Humans: nasty carriers of millions of diseases, avoid”, or “birds: flying bags of flu virus: don’t touch”? All animals are disease vectors and many diseases carried by other animals are transferable to humans.
Mount Albert, Ontario, Canada
Blighted lives
Your leader highlighted that deaths caused by medical errors, adverse drug reactions or hospital-acquired infections are the third leading cause of mortality worldwide (25 January, p 5). To these “iatrogenic” deaths we can add many people whose lives have been blighted by non-fatal iatrogenic impacts.
For example, I have been profoundly affected by the drug DES 鈥� diethylstilbestrol, a synthetic oestrogen given to many millions of women during pregnancy from the 1940s to 1970s to reduce risk of miscarriage, but which turned out to cause health problems in many children of those who took it. The problems caused by DES took 20 years to come to light. Some called it “the silent thalidomide”.
You could say I got off lightly 鈥� I was rendered infertile but have not had the vaginal and breast cancer it has caused in some DES daughters. DES has been a scourge through my life and threatens still with further unknown health difficulties. My DNA has been changed by vested commercial and political interests.
In addition, DES did harm in people through its use in livestock as a growth promoter. Although DES is no longer used for this, oestrogens in our food chain remain a concern, an issue summed up well by US environmental historian Nancy Langston ().
London, UK
Eats, shoots
In her discussion of excrement-eating pitcher plants in Borneo (1 February, p 43) Stephanie Pain suspects the many species of Nepenthes may still have a few surprises in store. Here’s one possibility: I wonder if the juices they produce have a laxative effect to promote output?
Euless, Texas, US
Robot love
Your leader on getting hitched to robots was quite right: “The love for a robot may become a love that dare not speak its name” (15 February, p 5). But first we need a name to avoid mentioning. How about “automating”? The robot itself (herself? himself?) could then be an automate. And presumably give you a lovebyte.
Long Buckby, Northamptonshire, UK
Glorious mud
Instead of Australia dumping millions of tonnes of sludge onto their Great Barrier Reef so they can export more coal to be burned (8 February, p 7), why don’t they send it to an island country that needs it because of rising sea levels caused by climate change, such as Tuvalu in Polynesia? If the sludge is as harmless as they say, the Tuvaluans should appreciate this gift. Australia might even get the world community to help sponsor it to preserve the islands.
New York, US
The drugs do work
Wilson’s article does point out some interesting initial evidence against the long-term use of antipsychotics in schizophrenia. However, I rather feel that it overstates the benefit of avatar-based therapy to reduce distressing voices. She says the “approach helped 15 out of 16 people in the study”. It is important to note that 26 people were recruited for the study, but 10 dropped out because they found the approach too distressing. Although avatar therapy may be useful, it is still in its infancy, and will only be suitable for certain patients.
London, UK
The drugs do work
Clare Wilson’s article highlighted the usefulness of talking therapies in treating schizophrenia (8 February, p 32). I fully support the UK’s National Institute for Health and Clinical Excellence guidelines in offering psychological treatment to those with a psychotic illness such as schizophrenia. However, Wilson’s article portrays psychiatrists as uncaring brutes forcing ineffective drugs on vulnerable patients. Not only is this stigmatising, it is also untrue and the quoted evidence is weak.
I am very aware of the benefits and side effects of antipsychotic medication and work tirelessly to improve the balance between the two, but many people with psychosis cannot manage without pharmacological intervention, and such articles make it harder to persuade them to accept helpful medication. Psychological treatment is a useful tool but not the whole answer.
Bournemouth, Dorset, UK
Dangerous minds?
In his letter (1 February, p 32) about Michael Brooks’s call to create agile minds rather than ever more science graduates in the UK (21/28 December 2013, p 38), Derek Williams points to the teaching of “thinking” in schools in Venezuela and wonders what we can learn from this. Free-thinking Venezuela has led the revolt against international capitalism, and has advocated wealth redistribution and enhanced government service provisions. It is extremely unlikely that Conservative MP and education minister Michael Gove will be proposing the introduction of the same sort of education in the UK.
York, UK
Rare meat
The best way to save an endangered species 鈥� such as the black rhino, which was the subject of your story on permitted trophy hunting to raise conservation cash (18 January, p 4) 鈥� is to farm it.
This also removes the dangers associated with the trade in rare animal parts, provides breeding stock to release into the wild for conservation and sustainable hunting, and helps emerging economies. Pygmy elephant burger, anyone?
Taupo, New Zealand
Not so fast
China has had considerable success in its crewed space programme. However, in your article on the rise of China as a space superpower you quote Richard Holdaway, the Rutherford Appleton Laboratory Space division director, as saying that the country is “progressing a lot faster than the US did with theirs in the sixties” (15 February, p 42). This is disputable.
China launched a crew of two and then three about a year earlier than the US did, following their respective one-man orbital missions. However, the US was substantially faster in achieving its first space docking, with Gemini 8, taking only four years and one month after its first crewed orbital flight, whereas China took nine years.
The US landed a man on the moon seven years and five months after John Glenn became the first American to orbit Earth in 1962. If China had moved as fast, it would have put someone on the moon in March 2011.
Farnborough, Hampshire, UK
Robot love
In your Cure for Love special, the juxtaposition of having a religion grappling with robot ethics (15 February, p 24), drugs to help cope with break-ups (p 26), and people marrying computers (p 29) poses a question. Will we need to develop an equivalent to the anti-love pill for android companions to take when they are inevitably dumped for the latest model?
London, UK