Letters: Prior Gaia
Fred Pearce bemoans the possible disappearance of the word ‘Gaia’ because
Lovelock is considering the advisability of replacing it with ‘global geophysiology’
(Forum, 28 May). I only want to point out that the word ‘Gaia’ was used
long before Lovelock. In 1931, at the University of Leiden in The Netherlands,
the biologist L. G. M. Baas Becking gave an inaugural lecture with the title:
‘Gaia or Life and Earth’. It dealt with the adaptation of organisms to all
possible environments on earth, but not, of course, with the more far-fetched
ideas that Lovelock later connected with that name.
N. G. van Kampen Tienhoven, The Netherlands
Letters: Diving doodlebugs
In the interests of technical and historical accuracy, I feel I must
comment on David Bullivant’s letter (2 July) concerning the V-1.
The pulse-jet, or Argus Duct, is appropriately described as ‘jet-like’
because, unlike a true jet, combustion is intermittent rather than continuous.
In some senses it was intermediate between a piston engine, albeit with
a gas ‘piston’, and a true jet. Its great merit was its extreme simplicity
compared to other engines.
The duration of flight of the V-1 was naturally limited by its fuel
but was not governed by it. The V-1 carried a ‘log’, a small propeller fitted
to the nose, which drove a revolutions counter. When a preset number of
revolutions had passed, corresponding to a given distance, the counter interrupted
the controls to the elevator, causing the tabs to lock over, and forcing
the rocket into a dive.
The ‘wing tipping’ manoeuvre is still widely debated and remains controversial.
There are doubts as to whether the wings of the two aircraft (fighter and
missile) actually touched or whether the effect was produced by aerodynamic
forces. What is clear is that the sudden movement caused the V-1’s gyro
to topple, with the result that it went out of control, diving or spiralling
to earth. I have never heard of a V-1 being made to reverse course and I
would be very interested if anyone can produce evidence of this.
What your correspondent, and many writers on the subject of the V-1
and V-2, tend to ignore is the economic aspect of the campaign. Both missiles
delivered about 1 tonne of high explosive. The manufacturing cost of the
V-2 was over 100 times that of the V-1. The V-2 required expensive alcohol
and liquid oxygen fuels; the V-1 required low grade kerosene and peroxide
for the launching catapult. In very rough terms, 100 tonnes of explosive
could be delivered by V-1 for the same cost as l tonne by the V-2.
Had the V-1 been launched in greater quantities, the British air defences
would not have been able to cope and the disruption to the Allied war effort
could have been considerable. We were very fortunate that the V-1 project
was never given adequate resources, was further disrupted by rivalry with
the army (the V-2 was an army project, the V-1 Luftwaffe), and was further
disrupted when the SS tried to take over both projects.
Cris Whetton Loddon, Norfolk
* * *
This correspondence is now closed – Ed
Letters: Slow boat to Boroko
What a pleasant surprise it was to receive 11 New 杏吧原创 binders
yesterday. On checking the invoices I noted the postage date was 20 August
1990. I asked some of my more long-standing colleagues about the binders.
It seems that 12 were ordered four years ago and one binder arrived shortly
after.
It is true that Papua New Guinea is a long way from Britain, but at
this rate the average speed for the other binders would have been less than
half a kilometre an hour. They obviously came on the slow boat, possibly
to China first.
Still, thanks to IPC Magazines for getting them here in the end. We’ll
be needing some more now.
Russell Jackson Boroko, Papua New Guinea
Letters: Grades of failure
Can anyone explain why there are only three grades of pass for GCSE,
that is, A, B and C but there are five grades of failure, that is D, E,
F, G and U.
Could it be that it is now considered politically incorrect to suggest
that a candidate has simply failed an exam?
Kay Bagon Radlett, Hertfordshire
* * *
Correction: Bill Cockburn and colleagues are developing plants that
produce antibodies at the University of Leicester, not at the University
of Birmingham as stated in the article ‘How tobacco can fight pollution’
(Technology, 16 July). We apologise for any confusion this error may have
caused.
Letters: Pointless protocol
It was disappointing to read Abby Munson’s advocacy that vaccines, foods,
plants, clean-up bugs and all the other uses of living organisms should
be stigmatised by the additional regulatory hurdle of an international ‘Biosafety
Protocol’ if they have benefitted from the application of modern genetics
to make them safer and more precise in their intended action (Forum, 25
June).
There is indeed need to regulate very carefully products such as vaccines
(genetically modified or not, the issues are the same), and to control by
quarantine laws the movement of exogenous species of plants, seeds, pests
and so on. Where it matters (for example, medicines and pesticides), there
are also and rightly various international harmonisation efforts and achievements.
The UN Environment Programme expert group Munson refers to did not unanimously
back a protocol, but produced a split report; the members with the strongest
biotech experience and background being generally least convinced that stigmatising
biotechnology in this way would serve any useful purpose, for conserving
biodiversity or anything else; rather the contrary. The report of Expert
Panel IV is available from the Geneva secretariat of the Intergovernmental
Committee on the Convention on Biological Diversity; thanks to the fairness
of our Danish chairman, it fully records the arguments for and against.
As we come up to the 20th anniversary of the Asilomar conference (which
recommended a moratorium on recombinant DNA research), there are no solid
grounds to revise the OECD’s 1986 subsequent conclusion, ‘that there is
no scientific basis for specific legislation to regulate the use of recombinant
DNA organisms’.
Munson is a policy researcher in the Cambridge Centre for Global Security,
and well aware of the challenge of feeding 10 billion people, achieving
far better than current health status for this increased population, and
simultaneously reversing the degradation of the planet. Those three challenges
are far beyond our current technologies and practices. Let’s not waste
time and resources witch-hunting the scientific innovations most needed
to improve them.
Mark Cantley Brussels
Letters: Dangerous deserts
In dealing with desertification, Fred Pearce still seems to be focusing
on past history and old news such as the inadequacies of the physical database
while ignoring the social and emerging political realities of this problem
(This Week, 25 June).
The UN Environment Programme is happy to explain the basis of the figures
we use, but should not be blamed for those we do not. Our claim that over
900 million people are at risk (not affected) from desertification is based
on the figures of the Food and Agriculture Organization for the population
that is economically dependent on agriculture for a living. Included are
those living in the rural areas of the arid, semi-arid and dry sub-humid
zones of the non-polar areas of the world.
We do believe that desertification is a major cause of human misery
because when people have no other means of support and their land will no
longer support them, they have to beg or migrate or starve. Good social
data is as sparse as good physical data, but there is increasing empirical
evidence of the effects. UNEP strongly supports the call for more science,
but then we are also accused of being self-serving and trying to perpetuate
‘institutional myths’. The UN has no need to create imaginary challenges;
there are more than enough out there which are brought to us by governments.
We most certainly do not believe that ‘the UN is best placed to prevent
desertification’ – quite the reverse. It is the people faced daily with
the problem who suffer most and who are best placed to do something about
it. The UN can only encourage and support them. As we have repeatedly said
over the last few years, any successful action will depend on the commitment
of national governments to create an enabling environment within which people
will be able to maintain the productivity of their land. The text of the
convention to combat desertification requires such a commitment.
We have gone further and suggested there is an implicit human right
which we called the Right to Remain (the right to stay on their land for
those who wish to do so) – a reference to the implicit responsibility of
governments to support their most marginalised citizens faced with adverse
circumstances. The ‘bottom up’ approach is now much sought after, but is
also clearly a national and local responsibility.
Franklin Cardy UNEP Desertification Control Programme Activity Centre
Nairobi, Kenya
Letters: Defending Darwin
How should we greet Sue Armstrong’s review of Philip Johnson’s Darwin
on Trial (2 July)? Shock? Horror? Incredulity? Fury? Surely a science journalist
realises (accepts? believes? understands?) that Darwin’s ideas come in two
packages: the fact of evolution and the theory of natural selection. There
is vigorous discussion about the mechanisms involved in evolution (that
is, about the mechanisms of natural selection) but, among scientists, very
little about the fact of evolution.
The great tautologists, creation scientists, persist in wilfully confusing
fact with theory. Sue Armstrong has given them some comfort. It would be
nice to shrug and simply treat such a review as unimportant confusion, but
all such misstatements of evolution provide ammunition for the creationists
who pose a real threat to the teaching of science in schools.
Peter Spencer Dundas, NSW, Australia
Letters: Defending Darwin
Armstrong is surely naive when she considers legal eagles as ‘ . . .
fine-tuned to finding flaws in intellectual arguments’. Their talent is
usually for twisting the truth and bamboozling the gullible. This half-baked
attack on Darwin is a case in point, and not the first to have come from
a lawyer.
Of course the first stages of an evolving eye are of benefit – ask a
flatworm or a nautilus. As for a rudimentary wing, ask a sugar glider or
flying squirrel. The key to the development of complex structures is often
pre-adaptation, evolution for a simple use before further adaptation to
a more complex and perhaps quite different one.
Feathers developed first for insulation, perhaps later for display,
and only then did they become adapted first for gliding, then for flight.
If Johnson’s book is an example of incisive legal thinking, no wonder our
legal system is in such a state.
Michael Walsley Hereford
Letters: Defending Darwin
As for the fossil record, it is known to be incomplete in certain areas.
Accordingly these incomplete areas cannot be used to prove or disprove Darwinism.
Darwinism is supported by the more complete areas of the fossil record,
and the observation of evolution in living species. It has ousted competing
theories, such as Lamarckian evolution and the Biblical Creation.
Darwinism is the best theory available and its basic principles are
correct. It may need extending, like Newtonian mechanics has been extended
by the special theory of relativity. This does not make Darwinism invalid;
on the contrary, it becomes more powerful.
Glyn Phillips Leigh-On-Sea, Essex
Letters: Getting wetter
I have carried out a number of studies on the wetlands and estuary of
the Indus Valley in the past four years, and can reassure readers that wetlands
as a whole are not disappearing from Pakistan (‘Can we stop the wetlands
from drying up?’, 2 July). In fact the appearance or expansion of some of
the largest wetlands, such as Beroon Kirthar and Hamal Lake, are a direct
result of the development of irrigation and river management. The adverse
effects of these activities – extensive growth of waterlogging and soil
salinisation, referred to in Pakistan as ‘the twin menace’ – have actually
provided more extensive wetland areas than existed previously.
Most of the existing wetlands are comparatively recent in origin, and
are actually a direct result of the recent expansion of irrigation in the
Indus Valley. Only a few permanent waters, such as Lake Manchar and Sindh
Dhoro, predate the modern wetlands, and these are generally relict river
meanders.
The inefficient management of irrigation leads to widespread waterlogging
and the development of seasonal saline shallow pools. These pools are of
enormous value to waterfowl, waders and other birds using the Indus flyway.
Every large dam that is created eventually spawns its own crop of new irrigation-related
‘problem’ wetlands. As some wetlands are reclaimed by drainage, others appear
elsewhere. Environmental assessments of water storage developments in Pakistan
have generally failed to take into account the positive value of the appearance
of new wetlands, being almost entirely obsessed with the evaluation of human
food production interests.
Douglas Cross Honiton, Devon
Letters: Getting wetter
Few would disagree with the sentiments expressed in your report. It
is noteworthy, though, that the majority of the projects outlined are large-scale
and outside the day-to-day experience of most of us. We can bemoan the situation
but actually do very little about it for ourselves.
Increasingly, we need to address the problems of the ‘ordinary landscapes’,
in which most of us live, work and recreate. Within these landscapes, we
can find our own local wetlands, which include farmland ponds, meres and
lakes. In addition to offering significant habitats, they have a wider,
day-to-day amenity value as diversified landscape.
Most farmland ponds derive from past commercial practices, such as marl
extraction. Before the intensification of agriculture in the postwar period,
many counties had thousands of such ponds. Though they have been largely
eliminated in the ‘cereal belt’, these ‘ordinary wetlands’ persist across
large tracts of the country: north-west England is estimated to have 30
000 such ponds in addition to its lakes, meres and ‘true’ wetlands. But
ponds have halved in number since the 1940s and their annual rate of decline
is almost 2 per cent. This rate does not appear to be slowing down.
To protect ‘ordinary’ wetlands in such numbers requires both a strategic
policy (such as Cheshire County Council’s ‘new-for-old’ policy towards developments
which threaten ponds) and the enrolment of the public to a monitoring and
conservation programme, such as the Parish Pond Warden scheme being developed
in Cheshire. But perhaps above all we need to address politically the causes
of such loss: it is significant that, while transport development, urban
growth and benign neglect have certainly taken their toll, the biggest active
cause of pond loss has been intensified agricultural production.
John Boothby John Moores University Liverpool
Letters: Allah's singularity
The evidence in favour of the big bang theory continues to pile up.
There could now be little or no doubt in people’s minds that the Universe
was created from a singularity with a big bang and that the Universe is
expanding. In this connection the following three verses of the Koran which
was revealed some fourteen hundred years ago, are vital.
Chapter 59, Verse 24: He is Allah, the Creator, the Shaper out of naught
(original singularity), the Fashioner.
Chapter 21, Verse 30: Do not the unbelievers see that the heavens and
the earth were joined together (original singularity) then We clove them
asunder (big bang) and We got every living thing out of the water (origin
of DNA?). Will they then not believe?
Chapter 51, Verse 47: The heaven, We have built it with power (big bang).
Verily we are expanding it (expanding Universe).
The words in parentheses are mine.
I. A. McDoom University of the West Indies St Augustine, Trinidad
Letters: Seed sovereignty
The battle for control over the world’s seed banks in the international
agricultural research centres (This Week, 2 July) results from the failure
of the Convention on Biological Diversity to resolve the issue of the status
of existing ex situ germplasm collections. These extremely valuable collections,
on which the ‘green revolution’ was based, are now in limbo; not covered
by the convention, and at present beyond the control of the country of
origin.
The need now is not for some public, accountable organisation to take
charge of the IARC gene banks, but to introduce national sovereignty over
samples in IARC gene banks for which the country of origin can be determined
– that is, the great majority of samples. In contrast, the present IARC
and FAO policy is to establish free access to samples under the auspices
of the FAO Intergovernmental Commission, rather than promote national sovereignty.
For once, the World Bank is to be congratulated. By approaching the
GATT world trade organisation on the future of the IARC collections, the
bank may be able to rescue seed samples from an uncertain future. Under
this GATT provision, the IARCs and FAO could assist developing countries
to re-establish national sovereignty over samples in IARC collections and
enable them to negotiate financial or technology-transfer agreements in
exchange for licensing commercial use of national germplasm.
David Wood Gillingham, Kent
Letters: Control is crucial
While acknowledging the contributions of Tilahun Yilma (and others)
in the development of recombinant vaccines, we have to disagree with the
article’s prescriptions for the global eradication of rinderpest (‘Man with
a mission’, 18 June, and Letters, 16 July). The article fails to take account
of either the merits of the currently licensed rinderpest vaccine, or, more
importantly, the organisation and management required to plan and implement
an effective animal disease eradication campaign.
The Plowright rinderpest tissue culture vaccine is an excellent product,
conferring lifelong immunity while being safe, cheap and having a very long
track record. While generally requiring a cold chain for distribution, it
is not as fragile as may be implied by the advocates of recombinant vaccines.
Using modern production methods the freeze-dried vaccine has a halflife
of thirty days at 37 degree C. Thermo-stability, which was highlighted as
a major problem in your article, is not a major constraint in the disease
campaign, but the quality control of the manufactured vaccine is and this
is now being given high priority.
Eradication depends much more on organisation, management and social
order than on the type of vaccine in use. Indeed, many countries (including
Britain) eradicated the disease before to the development of vaccine. Conversely,
under less favourable conditions, eradication may fail, despite ample resources,
including effective cold chains.
The suggestion that responsibility for vaccination should be left to
farmers on a ‘do-it-yourself’ basis is untenable. If vaccine is to be used
in an area, the target must be to ensure that a very high proportion of
the population is protected. This requires central control of vaccine delivery.
Perhaps more importantly, the eradication strategy requires that vaccination
be withdrawn as soon as this is appropriate, because continued partial vaccination
of populations may serve to conceal foci of infection. An important advantage
of a vector vaccine, however, could be that it would allow us to distinguish
between vaccinated animals and those which have recovered from natural infection.
We would question the view that eradication of rinderpest per se would
allow livestock keepers to manipulate herd sizes either up or down (the
text and the captions disagree on the likely direction). Rinderpest is only
a small part of the total risk faced by livestock farmers and the need for
sustainable management of grazing resources hardly requires emphasis. The
economic benefits of rinderpest eradication are very real, however, as once
the disease is eradicated, control costs are saved in perpetuity. There
are also important intangible benefits such as the removal of the fear
of periodic epidemics.
Disease control decision makers will continue to take into account a
very wide range of technical, managerial and social issues in developing
and implementing the coordinated programmes required to push the rinderpest
virus into oblivion. The ‘old guard’ may be cautious but their responsibilities
are great. Certainly the suggestion that they know nothing of developments
in molecular biology and are ‘downright antagonistic’ to new ideas is unworthy
of you and is far from our own experience.
Lindsay Tyler, Jonathan Rushton University of Reading