Vegan pets? Dogs, yes, but I wouldn't advise it for cats
I agree that dogs can be fed vegan foods exclusively, and it is true that nutrients such as vitamin D3 and taurine, previously only available to cats from animal sources, can now be provided in other ways (24 September, p 44).
Sadly, other essential nutrients for vegan cats, like arachidonic acid derived from fungus, aren’t yet licensed for animal feeding or, like preformed retinol, aren’t readily available. The main vegan source of vitamin A is beta-carotene, which is suitable for dogs but not cats.
There are vegan feline products out there, and, as I lecture on the subject, I have asked where their arachidonic acid and vitamin A come from, but they don’t answer. It is almost certain that cats can’t be fed safely on a vegan diet right now.
We just don't dress to impress any more
I was intrigued by the statement in “Apes, not angels” that “status… unlocks every animal’s ultimate goal 鈥� breeding rights”, as human status signals seem in decline (24 September, p 25).
Male fashion has become more staid, dull and standardised. Men, with a few exceptions, wear almost identical sombre, dark, formal clothes rather than the flamboyant, colourful and elaborate costumes that once signalled high status. We now have much lower global fertility than then. Any possible connection?
Let's not do our worst with the moon, too (1)
It seems that, not content with ruining one world, we are now intending to ruin another 鈥� the moon (17 September, p 38). In my long life, I have been a professional coral reef biologist and a professional and amateur speleologist. Both have taken me to some of Earth’s most wonderful and remote places, and in each activity, the ethos has been to tread lightly and leave no trace; to take necessary specimens and nothing more. Why doesn’t this apply to lunar exploration?
The moon’s fossil water is a valuable record of how water came to the solar system, so of course we must take samples. But mining this finite resource to provide water and oxygen to a lunar colony is simply criminal. I hope there will be a massive rethink before this project goes too far.
Let's not do our worst with the moon, too (2)
I have dreamed of a telescope installed on the moon that would point 24/7 at Earth. Perhaps such equipment could be part of the first cargo sent to the location on the moon where a base would be.
For one, its view might be a pleasant diversion for moon crews. But far more importantly, we earthlings would have the ability to constantly remind ourselves of the very, very thin film of our atmosphere, which we depend on to survive and ignore at our peril.
If it was good enough for Charles Darwin…
Mark Harper invites us to get the health benefits of swimming in cool, wild waters (17 September, p 25). Many well-known members of Victorian society flocked to the spa town of Malvern in England to consult doctors, who prescribed cold-water immersion of one type or another. Charles Darwin had such belief in his own cold-water treatment that he took his beloved daughter Annie to Malvern for the same procedures when she was unwell.
Now, we are finding that Darwin was probably right about cold water being of benefit to himself. His ailments today would almost certainly be tied to the subtle inflammation that is being found to underlie many unexplained illnesses. Is the work of Chill UK, and renewed enthusiasm for outdoor swimming, today’s Victorian cold-water treatment?
We must find nature's remedies before they go
The antimicrobial drug derived from the sap of the Australian rainforest blushwood tree is an interesting example of the medicinal possibilities of natural compounds derived from flora (24 September, p 15).
Tropical rainforests contain a great diversity of plant species. Considering many forests are under threat, every attempt should be made to investigate these species as soon as possible. Indigenous populations, having inhabited and used the forests for food and medicine for millennia, may be aware of useful plants.
I wish I could share optimism for the future
It brings me joy to encounter the optimism of youth (10 September, p 27). The only statement that I disagree with in William MacAskill’s article about ensuring a better world for coming generations, is that “a dystopian future is far from inevitable”.
My view comes after a lifetime of fighting for the exact same moral values that he holds. The evidence that our way of living is unsustainable in the long term first appeared when I was a young adult in the late 1960s and early 1970s. It seemed then that we really might be able to bring about a rejection of the consumerism that was ruining our planet.
That was a false hope. Nearly everyone, from the richest to the poorest, wants more. What we need to save Earth is sustainable diminishment, not growth.
Wave of dead trees must be put to good use
More dead trees as a result of recent drought in Europe will increase the wildfire risk, so rather than losing individual trees we might lose whole forests and, at the same time, add carbon dioxide to the atmosphere (17 September, p 13). The deadwood should be removed. It could be used to meet the firewood rush you described (10 September, p 8), where at least it would reduce the need for burning fossil fuels.
However, it would be much more efficient to process the deadwood to generate liquid or gaseous biofuels. Anaerobic heating, or pyrolysis, achieves this, leaving charcoal that could be used as a fuel or returned to the soil as a form of carbon capture.
For the record {08 October 2022}
IBM’s quantum computer fridge is 100 times colder than space (17 September, p 18).
In the study of links between the pandemic and premature puberty, pre-pandemic cases were found to occur at age 7.6, on average, compared with 6.8 during the covid-19 pandemic (24 September, p 8).