Here's why humans really evolved stamina
The idea that humans evolved endurance and stamina to chase prey might have it backwards. Prior to the development of sharp tools, we were ill-equipped to consume prey animals, lacking, as we were, the teeth and claws of a carnivore. Our early ancestors were gatherers, not hunters. It was us who were the prey, and our survival depended upon our ability to outrun not the predator, but our fellow humans (18 May, p 11).
If you and I, out gathering, were approached by a lion, I wouldn’t need to outrun the lion to survive, only you. Survival of the fittest at its most basic level!
Processed foods: addiction or just clever marketing?
You discuss the idea that food addiction might be akin to drug addiction. This idea overlooks the fact that ultra-processed foods are designed to be over-consumed. They are visually appealing, intensely flavoured, energy dense goodies that beg sensory seeking while providing little satisfaction. These factors strongly encourage people to eat more of them than is reasonable. When people do so, they are as much victims of marketing as addiction. Penalise the makers, not the consumers (25 May, p 10).
We need a new name for addiction (1)
I agree that the term “addiction” isn’t sufficiently precise to be used in a scientific context. It would be better to have something that gets to the heart of why addiction may be a problem in some cases to some people and not in others (Leader, 25 May).
Something along the lines of “harmful, unregulable dependency” perhaps.
We need a new name for addiction (2)
Addicted? Who? Me? Yes! I am addicted to 快猫短视频! I crave its stimulating food for thought! I can’t live without it! I can hardly wait for the next edition.
Orchids may be sharing food with many species
Although I see the potential for orchids to transfer food to seedlings via a fungal network, the study you describe reminds me of a limitation in experimental design 鈥� namely, that reducing complexity can give only a narrow window into a real-world ecosystem. I imagine a real mycorrhizal network doesn’t link up with a single orchid species, and if the fungus is actually in control of nutrient distribution, how can orchids ensure that food they input safely finds its way to others of the same species? Perhaps the symbiotic relationship actually involves several species inputting nutrients to the network, which pools them and distributes them (25 May, p 16).
Where to draw the line in a neurodiverse world
Grace Wade highlights an important point in her article on neurodiversity. The human race is diverse; every brain develops differently. So how do we make sure terms like “neurodiverse” are only applied to those who would benefit from such labels? How do we ensure that the neurotypical population gets the meaning and implications of such terms (25 May, p 39)?
Perhaps a better bet would be “neuro-atypical”. This would highlight to educators that these children would flourish under atypical teaching methods, and to employers that these employees would have different ways of working and different needs.
Farming emissions aren't inevitable
Again and again we read that some carbon emissions from agriculture are unavoidable. This view keeps resurfacing despite the best efforts of agroecologists, who will say that if we remove fossil fuel-intensive artificial fertilisers and farm in ways that support nature, instead of poisoning it, farming becomes carbon negative (25 May, p 12).
Thinking even more about thought
I have an extra point to raise on how to think about thought. It is that thought can’t exist without language. Pre-language actions depended on internal and visual associations in the brain. Imagine a hominid waking with hunger pangs in her tree long ago. She looks around and sees fruit in another tree. Eating fruit and hunger reduction are strongly associated in her brain. She leaps across and has breakfast. If you think you can have thoughts, simple or complex, without language, try it. You will find it frustrating as well as instructive (25 May, p 33).
Rational action economic theories are a dying breed
You reported on a game theory simulation that showed people failed to reach a state of rational action, even after multiple failures and repeated feedback. This was said to be in variance with economic theories. However, the result is in line with over 50 years of research by psychologists on micro-economic decision making (18 May, p 15).
Studies by Paul Slovic and Daniel Kahneman, plus others, show that judgmental heuristics and biases work to prevent rational economic behaviour. Very few economists today believe in rational human action economic theories.
It is quality, not quantity, that counts
I disagree that a steady decline in world population will hinder progress, provided we reach and maintain a sustainable level. Population in the year 1905 for Albert Einstein’s work was a fifth of today. In the 1960s, when we went to the moon, it was less than half its current level. It is quality and sustainability of civilisation and the environment that counts, not sheer weight of numbers (Letters, 25 May).
Cake tin is two slices short of a full load
A 200-square-inch cake tin of the dimensions given by Keith Walters (14.14 inches per side) only allows 98 slices exactly 1 inch by 2 inches. Unless you somehow combine the bits left round the edges (Letters, 25 May).