Beware of amateur scientists

By all means listen, but paying undue attention to amateur opinion hinders progress

THE MODERN world pays much attention to amateur opinion, and the media give just about equal weight to amateur and expert analysis in an increasing number of areas of significant public interest.

Poorly informed amateur opinion is often sharply at odds with expert analysis on a range of environmental and other scientific issues, sometimes winning the public argument and often causing great delay before the expert analysis is adopted. This occurs on issues such as waste incineration, genetically modified food, nuclear power, immunisation of infants, and many more. I believe that the weight accorded to an argument should be proportional to the expertise behind it.

An example of the conflict between amateur and expert analysis is outlined by Anthony Trewavas, a plant scientist at the University of Edinburgh, in Trends in Biotechnology(2008). Current conventional agriculture can support 1,000 people per square kilometre, compared with one person per square kilometre supported by hunter-gathering. The application of science and technology in agriculture has more than doubled crop yields in the past 50 years in western countries, thereby providing food security. And, in many developing countries, the "green revolution" has saved more than a billion from starvation.

As Trewavas outlines, however, since the 1950s agricultural policy has been increasingly interfered with by unqualified groups, backed by a few scientists marginal to agriculture. These have attempted to change agricultural policy, exaggerating minor problems and encouraging public anxieties about supposed dangers associated with food and, with some success, have opposed the implementation of agricultural research results sought by experts.

Frustration of mainline agricultural science is dangerous. World population will increase by 2.5 billion by 2050, which will require two- or threefold increase in agricultural yields. This can be achieved only by the intense application of science and technology.

Amateur environmentalist analysis of agriculture is deeply flawed. The GM crops condemned by environmentalists facilitate no-till farming, which conserves topsoil and reduces greenhouse- gas emissions by two-thirds. Also, genetic modification of crops facilitating their expression of insecticidal proteins allows a huge reduction in the use of chemical pesticides and leads to the recovery of natural pest predators. Many new GM crops are under development, including drought- and virus- resistant varieties, improved nutritional varieties, crops that produce vaccines, and more. Also, genetic modification disturbs the biochemistry of plants less than conventional plant-breeding methods.

Organic farming is promoted by many environmentalists on the basis that dangerous traces of synthetic pesticides remain on food after conventional farming. But, as Trewavas points out, this is to ignore the fact that higher plants synthesise more than 100,000 natural pesticides in order to kill insect herbivores. Many of these natural pesticides, when tested like synthetic pesticides, are equally toxic. Only 0.1 per cent of the total herbicide we ingest from eating plants is synthetic herbicide.

Widespread amateur campaigning against immunisation with the MMR vaccine on the basis of one flawed 1998 study, subsequently retracted, linking the vaccine to autism and bowel disease, caused a significant reduction in uptake of the vaccine despite strong reassurances from mainline medicine that the vaccine is safe. Reduced uptake of the vaccine caused several outbreaks of measles. The reduced uptake has yet to be fully reversed.

The media has an important responsibility here. When publishing conflicting analyses from amateur and professional sources, the relevant qualifications and experience of both sides should be highlighted. Also, their evidence should be carefully compared. In many cases the amateur “evidence” will contain more than a little intuition, fear, anecdote and ideology, and scientific support is usually limited to one or two scientists peripherally associated with the issue. Often the amateur position will have little support in the mainline peer-reviewed literature.

Amateur bodies must be free to critically interrogate the experts. If genuine questions and doubts surface, they must be dealt with by mainline science. But apart from this, paying undue attention to amateur opinion hinders progress. If I suffer from a heart problem I am quite prepared to listen politely to the opinion of my butcher, but I will make my mind up on the basis of the advice of my cardiologist.

PROF WILLIAM REVILLE

is a member of staff of the biochemistry department and public awareness of science officer at UCC. understandingscience.ucc.ie