Letters archive

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 …

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 …

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 …

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 …

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 …

I was fascinated by your account of fetal sharks observed by ultrasound to be swimming around in their mothers' uteruses ( 12 January, p 8 ). Adriano Milani Comparetti , a pioneer of paediatric neurology , was also interested in observing fetal movement using ultrasound. He would have raised his eyebrows at the article's description …

Zunum Aero hopes its planned hybrid aircraft – partially powered by electricity – will manage 1100 kilometres on a single charge ( 5 January, p 32 ). You provide maps showing some of the journeys that could be accomplished. Most can be done by train. A French TGV train has achieved 574 kilometres per hour …

I understand that the section of a flight that uses most energy is take-off. Would the range of an electric plane be significantly extended by a separate external launcher, similar to those used on aircraft carriers, to accelerate it up to take-off speed?

Paul Marks envisages a future in which aircraft use biofuels or derive electrical energy from renewables. It is a pity that he didn't go more deeply into the numbers, which make this seem unlikely. In 2017, for example, worldwide commercial aviation used about 400 million cubic metres of fuel. A square kilometre of oilseed rape, …

Alice Klein says that in Australia one in 20 people carries the genes for cystic fibrosis or for spinal muscular atrophy and one in 40 of those people has a partner who is also a carrier ( 22/29 December 2018, p 32 ). Those who are aware of being carriers may avoid having children with …