Autism correction
I was very disappointed with your article about a brain test to diagnose autism (6 December 2014, p 6). Autism is not a “psychiatric illness”. Such a term is grossly offensive to people with autism who are struggling to have it accepted as a different way of thinking, rather than simply a defect. In addition, “illness” is not a word I ever recall hearing in medical descriptions. The study was not about emotions, but sense of self.
Salisbury, Wiltshire, UK
Autism correction
鈥� Apologies. We should not have referred to autism as a psychiatric illness. In addition, we should have made clear that the focus of was on self-representation rather than emotion. These points have now been corrected in the online copy.
Great adaptations
Colin Barras considers whether adaptation helps evolution, but experts seem unsure whether this happens or matters (17 January, p 26). Surely plasticity can enormously influence evolution with only an indirect link to heritability? Take your example of fish. Suppose the water dries up, but many fish survive marginally with the help of plasticity, long enough to reproduce. If one fish then mutates helpfully to produce proto-legs or lungs the advantage is likely to give its descendants a chance of dominance.
If the mutation had occurred in a swimming population those fish would be more likely to be disadvantaged. Conversely, if the fish couldn’t survive on land in the first place, there’d be no opportunity for the mutation to grant any benefit.
Surely plasticity is likely to be a key catalyst for evolution, enabling a population to last in a hostile environment long enough for a benign mutation to spread.
Cambridge, UK
Great adaptations
Reading Colin Barras’s article on adaptation, I couldn’t avoid the conclusion that there was more than a touch of “straw man” in this hypothesis. I can’t see where the key difference is to separate it from what we have been teaching for years in evolution courses.
The traits that allow plasticity in the first place are going to be of the continuous type, which usually vary along a normal distribution. Selection moves the mean of these in the direction favoured by whatever selection pressure is applied 鈥� in the case of the fish, less water.
This is the hypothesis behind the divergence in “Darwin’s finches” 鈥� a group of closely related species found on the Gal谩pagos Islands. Subsequent selection over generations will alter the gene pool, both to represent the more favourable genotypes from the original population and to favour any mutations that further improve fitness in the new environment.
Whitland, Carmarthenshire, UK
What time is it now?
I enjoyed Laura Spinney’s exploration of the perception of time (10 January, p 28). We older people are commonly heard to complain that time seems to pass more quickly than when we were younger. I had presumed that this is due to life being increasingly routine, with fewer memorable moments in the near past to look back on. But could it be because there is less “stretchiness” in our time experiences, as Spinney describes it? Perhaps this stiffness is because our lives have fewer novel or stressful moments during which time is perceived to be slowed. More pessimistically, perhaps it’s because we have lost our ability to “slow down time” during those moments.
If David Melcher’s experiments with shuffled movie clips showed no correlation with the subject’s age, then there is hope that we could put the brakes on our perception of time by getting out of our routines and injecting some excitement into our days. Maybe I should buy a motorcycle?
Bethesda, Pembrokeshire, UK
What time is it now?
Questions of time are perennially fascinating, and Laura Spinney’s article is no exception. As my mother’s Alzheimer’s progresses, her perception of passing time has expanded 鈥� something many people have observed in relation to the disease. Having shared a memory with me, 10 minutes later she may refer to it by saying, “As I told you last week…”
This led me to wonder whether our perception of time is linked to how difficult it is to recall a memory. With the atrophying of brain pathways, maybe my mother was having more difficulty recalling very recent memories, and therefore interpreting them as having occurred further away in time than they really did.
Such an interpretation would also explain our perception of the present: it would be the interval between experience, memory creation and initial recall 鈥� the track that Laura Spinney’s article was taking us down.
Matlock, Derbyshire, UK
What time is it now?
Laura Spinney’s article provides a neurological explanation for an interesting phenomenon observed in traffic collisions. Witnesses occasionally report, with certainty, that events occurred in an order that differs from reality.
For example, they recall hearing a tyre burst, then the collision happening, when the physical evidence shows that the damage to the tyre was caused by the final impact. It has frequently been assumed that they were reconciling events into a “logical” order that fit their understanding of how such incidents unfold.
If this is how the brain works, it should sound a warning in other incidents such as firearms cases, where the question of who fired first is crucial.
Knowle, Solihull, UK
Take a deep breath
Simon Thompson mentions that parachutists yawn before they leap (20/27 December 2014, p 38). I’d imagine this has less to do with focusing on a task, and more to do with opening their Eustachian tubes in preparation for the imminent rapid change in air pressure.
He also neglected to mention the main reason some men yawn: it’s an excuse to get our arm around a girl’s shoulders.
Jomtien, Thailand
Australian fires
You write that Australia has been hit by “the worst bush fires in 30 years”, evidenced by the loss of 38 houses and more than 12,500 hectares of land to the flames (10 January, p 7).
But in February 2009 the Black Saturday fires in Victoria claimed 173 lives, with 414 people injured, and wiped out entire towns. One of those fires burned over 330,000 hectares, destroyed 1800 houses and killed 159 people.
While the recent South Australian fires are significant, especially for those affected, they are nowhere near the worst bush fires we’ve experienced in the last three decades.
Cardigan Village, Victoria, Australia
Just say no
If chaperon’s benefits in reducing alcohol consumption are to be proven, properly conducted human trials will undoubtedly be needed (3 January, p 8). But suggesting that the drug should first be tested on rats is nothing short of absurd.
Around 40 people have already tried the drug, so testing it on the wrong species would be a step backwards. Above all, we should take a long hard look at the ethics of inflicting suffering on animals to investigate something we already have such information on.
Tonbridge, Kent, UK
Giant snowballs
Rather than pumping fresh water across the ocean, perhaps we should consider the ideas of a former Patent Office examiner named Arthur Pedrick (3 January, p 34). He filed covering a wide variety of far-fetched inventions. With today’s technology perhaps we should consider his patent , which describes an arrangement for irrigating desert areas, such as those in central Australia, by rolling snowballs from the polar ice caps down a pipeline.
A partial vacuum in the pipe supplements the initial gravitational impetus, and allegedly so does the Coriolis effect as the pipe passes from high to low latitudes.
Great Shelford, Cambridge, UK
Conscious at a guess
Ian Beaver’s argument that machines could be considered conscious rests on the axiom that humans “are themselves calculating machines” (17 January, p 54). But humans are definitely not calculating machines.
When you catch a ball you do not calculate its trajectory; you guess it. When the ball is nearer, you guess again, hopefully better this time. Whenever you see, you have layers of guesses; you guess boundaries, guess shapes and guess objects.
Humans are guessing machines, not calculating machines. It makes a huge difference. Calculations are fragile 鈥� a slight change and the answer is completely different. Guesses are robust, can be learned, don’t require a software-hardware dichotomy and can be subject to evolution.
In the 18th century, they thought clockwork was a good model for humans. Now we think computers are. Wrong again.
Twickenham, UK
Trapped wind
Although I am no engineer, for decades I have proposed building submarine stores of pressurised air as a source of energy. I assure Steve Orchard that they could be large enough to power whole nations for days on end (15 November 2014, p 31), that they store potential energy mainly by raising water and could recycle generated heat efficiently.
Their many merits include ecological conservation and delivery of air at practically constant pressure throughout their working capacity.
I invite readers to inspect 鈥� or challenge 鈥� a discussion of these and related proposals at .
Somerset West, South Africa
Odds in favour
The Monty Hall problem is a good example of the difficulties we have in understanding probability (13 December 2014, p 32). The reason the notorious three-card scam works is likewise: most people simply aren’t well versed in the mathematics of gambling.
In this “game”, a gullible passer-by is invited to see whether they can find, for example, the queen. Three cards are placed face down and shuffled. The player stakes a pound and chooses a card.
If they lose, the dealer keeps their stake. However, if they win, the dealer only pays out an additional pound in winnings, when the payout should be on odds of 2/1, a three-pound return. These odds mean players will lose more rounds than they win and this, coupled with paying out lower winnings, keeps the dealer in profit.
In the Middle East, a “gully gully man” would board moored ships along with merchants selling their wares. He would do the same thing using three walnut halves and a dried pea beneath. I remember seeing one man using three upturned beakers, beneath one of which would be a day-old chick.
If your colleagues are willing, try this trick on them. After half an hour, you will have scammed your lunch money.
Bridge, Kent, UK
Using your nut
Intelligence is a slippery and elusive thing to define, as Anil Ananthaswamy’s article on plant intelligence (6 December 2014, p 34) shows.
However, in the context of living creatures I would define intelligence pragmatically as an appropriate, non-mechanical survival response to an ever-changing environment.
This seems to cover the case for plants as well as other organisms.
Bristol, UK
For the record
鈥� Rats! It was these, not mice, walking the treadmill in Adam Foster’s experiments into animal adaptation (17 January, p 26).
鈥� A character defect appeared in our article on personality and health: we misspelled the name of immunologist Daniel Davis (24 January, p 10).