Editor's pick: We need to remember some old lessons about genetic testing
You raise the question of whether all newborns might benefit from DNA testing (12 January, p 19). I see at least two problems that you didn’t mention.
If 140 out of 159 babies tested had one or more genes associated with disease, many parents will surely conclude that there is something wrong with their baby. It will take a great deal of careful counselling to counteract this conclusion. Very few fully qualified doctors could cope with providing this, let alone a start-up sequencing company.
I came across the second issue when I was a final-year medical student in 1970. Our teaching hospital was researching rhesus incompatibility in newborn babies. At the time, it was an almost untreatable, unpreventable condition. It arises when a mother whose blood group is rhesus negative has a baby with a rhesus-positive man.
Their first child might be only mildly affected by a reaction between the two incompatible blood groups, but the mother may develop antibodies that affect a second child, sometimes with grave, if not fatal, results.
The most obvious thing to do was to ascertain the blood groups of the parties involved 鈥� mother, baby and father. It soon emerged that around 25 to 30 per cent of the babies had blood groups that could not possibly have arisen if the “father” was who he thought he was.
The percentage was rumoured among colleagues to be higher in the babies of mothers who had had a problem with a first or second pregnancy. The research project ground to a halt.
DNA testing will reveal much more detailed results. In several published cases, such results have brought adults to the realisation that their parentage isn’t quite what they thought. Discovering this with newborn babies may open another counselling headache, to put it mildly.
Some first class solutions to air travel pollution (1)
Paul Marks mentions replacing aviation kerosene with biofuels (5 January, p 32). One problem with this is that aircraft engines will still generate various oxides of nitrogen at the high temperatures involved. Another is that emissions, including carbon dioxide and water vapour, occur at altitude, where they have a disproportionate effect on climate. Flying lower and slower could reduce emissions, as could stopping to refuel on long flights. The high weight of fuel carried on these causes higher consumption.
Some first class solutions to air travel pollution (2)
Another measure for reducing the environmental impact of air travel is curtailing or abolishing first class and business class. I have seen estimates that a first-class seat takes between five and seven times as much space as an average economy seat, and this doesn’t take into account extra crew to service these passengers.
It seems to be an accepted premise that as long as you have the money, you can pollute six times more for the same activity.
Some first class solutions to air travel pollution (3)
Marks mentions electric vertical take-off and landing (eVTOL) aircraft. To suggest that these might replace commuter trains is, frankly, frightening.
According to figures from the UK , there were some 1.7 billion rail journeys in the country in 2017-18, of which over half were commutes or for business purposes. If just 1 per cent of these journeys were switched, we would see at least 10 million eVTOL flights per year. For what purpose? This solves nothing and creates new problems, not least for those under their random flight paths.
To reduce emissions, we need jobs to be available where people live, to minimise travel. All new major housing developments should come with mandatory business space to attract work that people can travel to on foot, bicycle or local transport. We don’t need more crazy ways to perpetuate the daily commute.
First class post 鈥� 26 January 2019
Many women return to work ‘part time’ but do their previous job in less time for less money
EDgypsy to the suggestion that flexible working is more productive and healthy (12 January, p 39)
An iguana's view on land mass evolution
Zoologist Peter Grant suggests naming the chain of sunken islands near the Galapagos “Iguania” and Felipe Orellana-Rovirosa, whose work you report, suggests “Darwinia” (5 January, p 15). I propose calling them all the Galapagos Chain.
Humans may think they see one archipelago of seven islands and a nearby chain of submarine mountains. But iguanas survived a sea crossing to reach the area and have bred there for more than 10 million years. Islands keep popping up and going down, but that is no problem for iguanas because each new island is close to the old ones before these are eroded, slide off the hotspot and sink beneath the sea.
Extending the window for evolution of the Galapagos flora and fauna from 3 million years to a more useful 15 million years or more was the viewpoint I proposed 40 years ago when plate tectonics was in its infancy and I was a geologist from the University of Durham, UK, and working at the Galapagos National Research Centre.
Where children have play, adults have art
David Robson talks about the extended infancy in humans that allows us time to develop cognitive skills through play and its role in enabling innovation (22/29 December 2018, p 65).
This brought to mind an insight expressed by musician Brian Eno in his 2015 John Peel Lecture (). He says children learn through play, but adults play through art. Could this help explain our need for artistic endeavour? Eno suggests that adult play – engaging with art – is how we rehearse for life events. He notes that by immersing yourself in art, you are not only increasing your ability to imagine and flex your mental muscles in other worlds, but you are also looking back at the world you are actually in.
Most bacteria aren't as large as that
Leah Crane describes a Bose-Einstein condensate of caesium atoms 26 micrometres across as “the size of some bacteria”. A few bacteria are this size, and I've spent a large part of my career researching them. But your average bacterium is less than a tenth as large.
A chromosome puzzle in human ancestry
You frequently discuss humans interbreeding with Neanderthals and Denisovans (for example 22/29 December 2018, p 35). Presumably this was going on further back in the lineages.
All these species have 23 pairs of chromosomes; other great apes have 24. Each of one certain pair of our chromosomes consists of two ancestral units stuck end to end with “telomere” end sequences in the middle.
How did the first ancestor with 23 chromosome pairs have offspring with others that had 24? What advantages do 23 chromosome pairs give over 24?
I detect some politics happening here
For several months, I have detected an increased number of 快猫短视频 articles covering our dire position with respect to climate change. You appear to have taken the position that global warming is a fact and that extreme measures will have to be taken for us to be successful to combat it.
We should ask ourselves whether this is a proper attitude for an impartial journal. And of course, the answer is a resounding yes. Thank you. Keep up the good work. Tell it like it is. If science becomes politics, then so be it. We will only get one chance at the experiment of dealing with this.
Thank you for the help coping with Parkinson's
I thank Mike Aris for sharing his technique for handwriting with Parkinson's disease (Letters, 22/29 December 2018). My wife Brenda was most distressed to lose her writing abilities. Using Aris's method of sounding the letters, she has regained a lot. She was amazed that she could produce a recognisable set of initials on a delivery driver's pad, something most of us struggle with at the best of times.
Beware the lure of young blood treatments
Early indications that protein in blood from younger individuals can offer hope for people with Parkinson's and Alzheimer's are promising (5 January, p 6). I hope the proteins responsible are isolated quickly for clinical use. I fear that if they are not, limited stocks of young blood may promote young people being abducted as a source of blood for the old. Vampire devotees and authors of medical horror will have plenty of scope.
A sideways look at the carbon dividend plan
Matthew Benton highlights the potential benefits of a carbon tax and dividend scheme (Letters, 22/29 December 2018). This returns the proceeds to taxpayers and encourages spending on low-carbon purchases.
The concept ought to be particularly attractive to US conservatives once they realise that it is effectively a tax on non-citizens, including illegal residents, who will pay the tax on purchases but will not receive the dividend.
For the record – 26 January 2019
鈥� Vitamin B12 supplements may be synthesised from scratch, derived from animal products or extracted from bacteria (The Last Word, 5 January).
鈥� We are still in the Quaternary Ice Age, and the previous interglacial period within it ended 115,000 years ago (22/29 December 2018, p 54).
鈥� The image by artist Dan Holdsworth was in fact of the Argenti猫re glacier in the Chamonix region of France (15 December 2018, p 28).
鈥� Data point: statistician Joshua Loftus (12 January, p 7).