When votes count
Ian Stewart’s article on the mathematics of voting seems to take pleasure in the fact that no voting system is perfect, while failing to acknowledge that the relative merits of voting systems should be investigated and qualitatively assessed (1 May, p 28).
To my mind, the voting system here in Australia has several advantages, not least of which is that preference voting means every vote counts. You can vote for a minor party, assured that if it turns into a race between the two major parties then your order of preference, and your vote, counts.
In addition, enforcing mandatory voting means that the result is truly representational of the total electorate. Political parties must attempt to appeal to everyone 鈥� as everyone will vote. This encourages politicians to consider the effects of policies over the whole socioeconomic spectrum. With this system everyone votes, and every vote counts.
Mandatory voting affects results far more than the exceptional cases given prominence by Stewart’s article. He would also do well to consider the preferential, proportional system used in the Australian Senate, and the advantages that brings to a government’s second house.
No system is perfect, but some are a lot better than others.
From David Goddard
Ian Stewart predicts an ordering paradox arising from a preferential voting system. It is not a paradox at all; it is merely a dead heat. Each notional candidate has received an equal number of first, second and third preference votes, so surely it would be something of a flaw if the system were to identify a victor in such circumstances.
While a draw would provide a practical challenge were it to happen, with a realistic number of voters such a result becomes vanishingly unlikely.
Perth, UK
From David Monkman
There are difficulties in turning the total national party votes into a proportional number of MPs for each party. The solution lies in giving each MP multiple votes when they come to vote in parliament. The number of votes a particular MP could wield would be calculated by taking all the votes for their party, from every constituency, and sharing them evenly between all its MPs.
Every party that had at least one MP elected would be proportionally represented, and the important MP-constituency link is maintained. Vitally, voter turnout would probably increase, because no vote, even in a safe seat, would be wasted. Above all else the result would be fair.
Ramsey St Mary’s, Cambridgeshire, UK
On biodiversity
It is a major oversight that your article on biodiversity mentions micro-organisms only fleetingly (24 April, p 32).
Furthermore, you report that “our best estimates so far give the number of species between 1.4 and 1.9 million”. These numbers ignore David Hawksworth’s widely accepted estimate of , with the number of already named species closer to 100,000 than your value of 70,000.
All the larger organisms upon which this feature focused so closely have intimate interactions with numerous microbes. Thus for each plant species that goes extinct, diverse microbial symbionts may also be doomed.
As Tom Curtis stated: “If the last blue whale choked to death on the last panda it would be disastrous but not the end of the world. But if we accidentally poisoned the last two species of ammonia-oxidisers, that would be another matter. It could be happening now and we wouldn’t even know” ().
There is more to biological conservation than simply animals and plants.
The editor writes:
鈥� There is no central catalogue for recording species descriptions and there may be considerable double counting, hence the current estimate. Microbial numbers are particularly uncertain: the American Society of Microbiology published a questioning the notion of species at this level, given the degree of horizontal gene transfer.
From John Morris
Your article on biodiversity fails to mention the effects of geology, topography and soils. While working in land development in North Borneo (now part of Malaysia) in the 1950s and 1960s, I saw aerial photographs of the natural forest prior to its destruction. It was possible to identify areas of land with particular soils by marking the boundaries of the different natural forest species groups. The forest species groups that occupied soils derived from basalts differed from those on soils derived from andesites, and on those derived from various sedimentary rocks in the region.
Not only were certain groups of tree species to be found on the differing soil types, but the orchids and other species growing in the tree crowns varied similarly.
Regrettably all this has now been destroyed so that scientists can no longer examine these absolutely minute natural species groups and their relation to the underlying rocks and soils.
Horsham, West Sussex, UK
From Mike Hancock
Discussing biodiversity in the tropics, Emma Young mentions that it was found that “tropical species had more than twice the rate of molecular evolution” compared with species from cooler regions.
As a 16-year-old doing my O-level exams back in 1955, I was taught that chemical reaction rates roughly double for every 10 掳C rise in temperature. Later I learned that the Arrhenius equation implies much the same. Perhaps the increased biodiversity in the tropics is partly related to simple chemical reaction rates.
St Austell, Cornwall, UK
Heavy lifting
In her article on how much a human can lift, Jessica Marshall begins by mentioning Andy Bolton’s record for the heaviest dead lift (17 April, p 34). Bolton holds this record in power lifting, but the heaviest dead lift record belongs to Benedikt Magn煤sson of Iceland, who lifted 498.9 kilograms using straps.
Marshall also lists short limbs as favourable to strength. This is true 鈥� except in the case of the dead lift. As a weightlifter, I have found that those of us with longer limbs are actually at an advantage compared with our stockier competitors, because we need to pull shorter distances. In fact, different limb and torso lengths result in different aptitudes for lifts.
Pond life
I found the explanation for Minnesotan frog deformities put forward in Jessica Griggs’s article somewhat implausible (13 March, p 48).
Griggs correctly states that there are perfectly natural reasons why some of the frogs may have had limb irregularities, and suggests parasites and dragonfly larvae as causes for the extra and missing legs respectively. However, it is extremely unlikely that these two unrelated factors were the causes of deformity in 50 per cent of the frogs in the same pond. It is more likely that both deformities have the same underlying cause.
If the deformities are indeed down to some form of parasite or larva, then the increased numbers of these organisms at the pond site will be the result of environmental changes, most likely increased pollution. To shrug one’s shoulders and say that the pond just had bad luck is an intellectual cop-out.
The editor writes:
鈥� Research by Brandon Ballengee, Stanley Sessions and associates found deformities in amphibians in Asia, Australia, Europe and North America. As pollution levels varied in each area, Sessions’s team has proposed the parasite/larva explanation as the most likely. However, many labs are researching amphibian limb irregularities and no consensus has yet been reached.
Carcasses for crops
Sam Little recounts how donkey carcasses used to be planted beneath asparagus fields to improve yields (1 May, p 25). It was traditional when constructing a vinery in Victorian times to bury a large animal, even a carthorse if available, in the bed where the vines were to be planted. In later times when planting a new vine a pig or sheep was buried in the bed.
Traffic hack
Nic Fleming envisages a future of self-driving cars that communicate with each other about road conditions (3 April, p 34).
If this vision becomes reality, each car will in effect form part of a self-optimising system. Unfortunately, when such systems contain no slack, they can fail spectacularly if a single component goes wrong; traffic jams are a perfect example.
I would guess that we can look forward to a future of 200-car pile-ups. They might be rare, but they will certainly get headlines.
Fleming did not discuss the potential for this interdependent, computer-driven network to be hacked, or even poisoned by a few cars being deliberately used to feed it false information. There are many who might profit from causing, or threatening to cause, widespread traffic disruption in a major city.
For the record
鈥� Jeffrey Macklis, whose studies of brain-cell generation we mentioned (3 April, p 29), is at Harvard University, not MIT. Contrary to what we stated, many groups apart from his own have found so-called “progenitor” cells, possibly left over from brain development, in parts of the brain in which new neurons are not normally produced. In mice, Macklis has found molecular controls that tip these progenitor cells into becoming corticospinal motor neurons.
鈥� We seem to be having a little trouble with our geography… the Matterhorn is of course on the Swiss-Italian border (1 May, p 17). Issaquah is in Washington, US (1 May, p 25). The US deserts we mention in our article on leaf shape are in the West, not the Midwest (8 May, p 6).
鈥� Not to mention timescales. In 5 to 6 months you could get to one of the asteroids mentioned in the diagram 鈥� and back (1 May, p 12).
鈥� And finally names. We misspelled George Michelsen Foy’s name in our review of Zero Decibels: The quest for absolute silence (1 May, p 44). And we renamed the director of public relations at Medimmune, who is in fact Karen Lancaster, based in at the firm’s headquarters in Gaithersburg, Maryland, US (UK and US editions, 1 May, p 46).