Persistent populace?
An optimistic Jesse Ausubel tells us we are so clever that we will always figure out a way to beat Malthusian predictions of population catastrophe (26 September, p 38).
It has indeed worked so far, as exponential population growth smacks up against merely linear resource growth. In the end, though, he’s counting on us finding increasingly clever ways to balance on the branch that we’re sawing off. He may be right, of course. If so, perhaps we could all meet and discuss it one day over a nice plate of jellyfish with genetically engineered yeast sauce on the side. Delicious.
From Simon Dicker
Bob Holmes’s article on the effects of global warming paints a bleak picture of the Earth’s future, one in which, as researcher David Jablonski asserts, the weeds and the cockroaches will do well, and humans won’t (3 October, p 32). Holmes describes these species as able to exploit disturbed environments 鈥� but this is exactly what humans do too.
As a species we are massively overusing our planet and I agree that mass starvation will occur, but evolution is about survival of the fittest. After we have wrecked the planet through global warming and overconsumption I think that the most war-loving humans will still be around in huge numbers, sharing Earth with the mosquitoes, cockroaches and Japanese knotweed.
Philadelphia, Pennsylvania, US
From Geoff Kirby
Paul and Anne Ehrlich begin their attack on population growth by drawing attention to the “increasing shortages of food, water and other resources and growing numbers of hungry people” (26 September, p 36).
However, the charts that close part one of your “Blueprint for a better world” series show that hunger, malnutrition, extreme poverty and child mortality have reduced since the early 1990s, and that food supply and access to clean water for drinking and sanitation have improved (12 September, p 30). GDP per capita is steadily rising even in sub-Saharan Africa, which is the benchmark for deprivation. Additionally, Bj酶rn Lomborg wrote in his book The Skeptical Environmentalist that the calories consumed per capita per day in the developing world have risen steadily since 1960.
What a shame that an otherwise interesting article should be based on such unfounded premises.
Weymouth, Dorset, UK
What's the buzz?
Caroline Williams casts doubt on the received wisdom that the bees’ waggle dance is about communicating the direction and distance of a source of food (19 September, p 40). Having kept bees for 37 years, I concur.
Waggle dances can be seen most frequently in early spring. If their purpose is to provide directions, why should that be so? Foraging sources, and therefore their location, change throughout the year, so dances pointing other bees towards them should be equally frequent, whatever the season.
Other observations are also at odds with the conventional explanation of the waggle dance. When I have had occasion to rotate a frame from a hive from vertical to horizontal, bees that were already dancing continued to do so. This change in orientation, which could only confuse their directions, seems not to affect the dance.
When it comes to locating forage sources, vision ought to be sufficient. Bees’ vision is based in the ultraviolet, and shows flowers as star-bright against a grey background.
A bee colony requires a great deal of organisation. The waggle dance and pheromones are not enough to direct day-to-day actions; there must be another method of communication. It might be that bees communicate using their front legs. I have seen them stand on their four back legs and rapidly rub their front legs together in what could be a form of sign language. Or perhaps they rub their antennae together for the same purpose. Any of these methods could be used by the bees to give directions to food sources, if required.
Until there is a better explanation of the waggle dance, perhaps we should accept that the girls just like to dance. Can’t we at least acknowledge the possibility that bees have higher emotions symbolised by dance? With my experience of bees, I can.
From Margaret Woodhouse
The discussion on the interpretation of the bees’ waggle dance missed an important point. Researchers use an observation hive with a glass panel, which allows people to view the bees’ movement.
Within a conventional hive there is almost total darkness, so it is inappropriate to consider bees as “watching” the waggle dance. Researchers need to consider information systems other than sight to understand how bees communicate.
Cardiff, UK
From Ken Green
I kept bees for five years. My hives were set in a line in front of a huge laurel hedge which faced due south. Some 550 metres distant, at 45 degrees to the line of hives, and behind a large block of stables, was a nectar treasure trove of lime trees.
To get to the trees, navigating around the large obstacle, the bees would fly along in a line, before changing direction when they encountered “marker” bees hovering about 1.5 metres above the ground at two points along the route.
Penpathy, Cornwall, UK
No second chance
I agree with Harriet Coleman (22 August, p 24) that the debate about global warming is really about preserving our way of life, and that “in the worst case we will be trying to save enough civilisation not to have to start again from the Stone Age”.
However, I would also add that the chances of us being able to start again from the Stone Age are remote, since we will have blown what is most likely our only chance. Technological civilisation, as I think astronomer once pointed out, is almost certainly a one-shot affair, since it entails using up all the easily available resources and thereby making it virtually impossible for any subsequent civilisation to arise that uses anything other than muscle power, wind, water and burning wood.
Mortality rate
In his article on genetic engineering, Michael Le Page claims that genetically modified Golden Rice will “help to improve health and reduce child mortality, which will ultimately contribute to a reduction in population growth” (12 September, p 37).
I disagree. Surely the population will increase if people live longer because they are healthier, and sick children do not die but live to a ripe and productive age.
Michael Le Page replies:
鈥� According to the child survival hypothesis, the less likely children are to die, the fewer children their parents have, so reducing child mortality rate eventually lowers the fertility rate. The short-term effect of improving child health will be to increase the population, but in the long term it helps reduce population growth.
Relative earnings
The chart on “extreme poverty” at the end of part one of your “Blueprint for a better world” series errs in using the classification of earnings below $1.25 per day (12 September, p 30). This amount, off the tourist trails, in northern India or Chad, for example, would probably buy a whole family a decent meal, but in Europe or the US they would need much more than that for the purpose.
It is not sensible to assess poverty in these monetary terms; it needs to be compared with the local cost of living. I concede that this is often difficult to define, but “$1.25 per day” doesn’t mean anything without comparison.
Improving Earth
I found your “Blueprint for a better world” series interesting (12, 19 and 26 September, and 3 October), as I am involved in an endeavour called , which has similar aims.
To reduce population by 50 per cent while also offering children and parents a better interactive future, I suggest a family system in which a couple has one child and then joins with another couple with one child. The children have companionship, and the burden of raising the children is shared between four adults. Also, if one couple should ever split, the children may still have three adults for support.
To immediately reduce the pollution due to cars, without the need for new types of vehicles or fuels, we could raise the legal driving age to 21. This would not only reduce greenhouse gas emissions, it should also eliminate the injuries and deaths now caused by young drivers.
Geo war
Another plea in your pages for geoengineering (12 September, p 34) makes me wonder if I am alone in my concern about the potential for warlike abuse of these techniques. Several of those now discussed could be used to intentionally damage territories and populations by inciting droughts or floods, or by changing sea or air chemistry.
The 1978 Environmental Modification (ENMOD) convention banned hostile use of geoengineering techniques. With talk of implementing these technologies, isn’t there a case for digging out and updating that convention?
You dirty rat
In Henry Nicholls’s article on taming wild animals, I was intrigued to read that “You can do anything with the tame rats… you can move their arms and legs” (3 October, p 40).
Did those rats that were bred to be aggressive also have arms? Was there interest from the military in the idea of equipping them with tiny weapons?
Elementology
Copernicus was a great scientist and should be commemorated, though Aristarchus of Samos came up with the heliocentric theory 17 centuries earlier. But it seems perverse to name element 112 after Copernicus when there are contributors to the periodic system who have not yet been honoured (25 July, p 7).
For the record
鈥� We misspelled John Cockcroft’s name in our editorial on ITER, sorry (10 October, p 5).
鈥� Apologies also to Georgios Yannakakis whose name we misspelled in our article on adaptive computer games (10 October, p 21).