Letters archive

David Robson describes "earned dogmatism" as the tendency of a person to overestimate their expertise based on past training ( 23 February, p 30 ). I used to advise PhD candidates as a statistician, and was particularly aware of examiners from many disciplines who claimed sweeping knowledge of statistical methods, apparently based on an introductory …

You report the idea of CRISPR gene editing to limit the number of unwanted male calves born to dairy cows ( 9 February, p 13 ). Surely it isn't beyond us to develop a breed of cattle that lactates without giving birth? I do accept that there may be ethical or moral issues with this …

You report possible links between mouth bacteria and Alzheimer's, and note doctor Barry Marshall won a Nobel prize for linking Helicobacter pylori and stomach ulcers ( 2 February, p 6 ). Robin Warren initiated that idea, began the research and shared the prize.

Some peoples cut off fingers in mourning, report Margaret McGovern from Canada (Letters, 23 February ) and Ted Webber from New Guinea (Letters, 23 March ). When I worked in Papua New Guinea, a young employee walked in with a large bandage on a finger of her left hand. She had cut off the top …

You report the alarming decline of insects due to habitat loss and climate change ( 16 February, p 6 ). The response of insects to the latter is likely to be adaptation by evolution. Creatures with shorter lifespans can adapt faster and displace those who live longer. Those with the shortest lifespans, such as cyanobacteria, …

You illustrate the carbon footprint of a kilogram of cheese and other foods ( 16 February, p 30 ). It would be more useful to see the carbon footprint per kg of dry mass. I estimate that milk (90 per cent water) has an impact of 12.5 kg of CO 2 equivalent per kg of …

You make a persuasive case for looking at carbon dioxide emission per calorie. I would like to see a chart that shows this.

Having yeast make cannabinoids sounds useful to medicine ( 2 March, p 9 ). I cannot imagine, though, that they will stay cloistered in the lab for long. They could be transferred as easily as a sourdough starter, allowing interesting wine, beer and bread to be made.

You report that association football players are working harder and getting injured more often ( 2 March, p 16 ). These health and injury issues are common to many professional sports. One of the worst problems in association football, though, is that players are expected to be able to head the ball – as are …

Willem Windig is surely right when he says that "illusion" is a word used far too freely (Letters, 9 March ). The one view we cannot take of consciousness and mind is that they are an illusion. If we do then, logically, that view must itself be an illusion, since it is part of our …