Surge in stomach acidity may have served a purpose
The story on the possible link between emotions and gastric pH was interesting and thought-provoking. Could this be an evolutionary protective mechanism for early humans, who, being predominantly hunter-gatherers, may have been compelled to eat things that might not have been fresh in times of scarcity?
Fear, disgust or even caution may have led to a surge in acid production that could potentially destroy any significant microbial content within the meal, thereby rendering a degree of protection. We can perhaps thank our ancestors for our “gut instinct”(18 March, p 16).
A calorie-controlled generation is out there
You recently ran a piece on the possible link between calorie restriction and longevity, commenting how difficult it is to run proper trials(18 February, p 17).
Has anyone looked at the UK population around the time of the second world war and soon after? Rationing provided a decent, though boring, diet for everyone. I was often peckish, but never starving. Rationing went on into the 1950s. I am 90 and I know many contemporaries who seem to be lasting well.
Let dogs be dogs and cats be cats
As an admirer of both pet cats and dogs, Michael Marshall’s claim that our meowing companions are “aloof and indifferent” in supplying “cupboard love” for food reeks of anthropomorphised slander, of manipulative felines yet again losing to “man’s best friend”. Please allow both furred companions to be themselves 鈥� that is to say, sentient beings entitled to their species’ and individual natures(11 March, p 46).
Dogs and cats enhance our lives in different yet complementary ways. Dogs constantly seek affirmation and cats dispense approval when they deem such gifting deserved. Shining a light on the secondary gain basis of conditional or total devotion ruins the effervescent allure of cats and dogs. Long may their behavioural templates stay a mystery!
On the evidence for a supreme being (1)
In contrast to Bryn Glover, I believe in the existence of a supreme being, despite there being no evidence from the scientific method for one. And if scientific evidence for such a being arises, I will stop believing. After all, there is a replication crisis in much of science(Letters, 18 March).
On the evidence for a supreme being (2)
The science-religion debate is akin to some post-human era where intelligent rats ponder the fossil ruins of our civilisation. They attribute such objects to unknown natural processes and develop elaborate theories as to their origin. Then they discover we once existed and created such marvels as skyscrapers, cathedrals and the Hoover dam. Would the discovery that intelligent beings made such things mean it was no longer worth it for them to study the scientific and artistic principles utilised in the objects’ design?
On the evidence for a supreme being (3)
God would surely be clever enough to create a universe in which they can’t be observed. We are well accustomed to authors of sci-fi and fantasy fiction creating worlds out of their imagination. If you asked Albus Dumbledore who J. K. Rowling was, or Gandalf who J. R. R. Tolkien was, they would not only have no information, they could argue that these authors were unnecessary. Their worlds function consistently without any need to hypothesise an author.
I conclude that the scientific method has nothing to tell us about the existence or non-existence of God.
This frozen head would surely never hop again
Your review of the Frozen Head podcast describes a rabbit brain thawed in an “almost-perfect state”, but there are caveats to that(4 March, p 35).
The brain in question was “fixed”, or preserved before freezing in glutaraldehyde. This is similar to, but more potent than, the formaldehyde used in embalming fluid. Fixing means rapidly and irreversibly killing something and preserving it in a close-to-lifelike state.
The brain may have been almost perfect for microscopy, but not for other things, including living and thinking inside a rabbit head. It is beyond imagination that such tissue could be reanimated.
We need a fine-grained picture on long covid
For argument’s sake, let’s accept that the long covid case numbers suggested by researcher Hannah Davis and her team are reasonably correct. Their work, we are told, implies 75 million cases worldwide. If it were feasible to do so, breaking this figure down to a local level might show us a different side to long covid(4 March, p 14).
Is the picture uniform across the globe? If yes, then the 10 per cent rate of this condition in those who get covid-19 would stand as a working estimate pending long-term analysis. If, however, the answer is no and there are variations, then questions arise. For instance, perhaps the rate of long covid is significantly higher in lower-income countries where you might guess higher rates of poverty and lack of full access to care would disadvantage patients.
If it were significantly lower, this might suggest that long covid is tied to unknown factors in higher-income countries.
The race to cut emissions is becoming more urgent
Alan Walker criticises the assumptions used to estimate the additional very-long-term emissions produced by having an extra child that imply a rather large carbon footprint. That is fair enough, but we do need to drive home the necessity of urgent cuts(Letters, 18 March).
The new synthesis report from the Intergovernmental Panel on Climate Change says emphatically that we have to get emissions down by 2030, then further down, then remove carbon dioxide from the air. We need a laser-like focus on these decades. What we get wrong in the next 10 years will be very hard, and perhaps impossible, to fix.