Journals weed out straw men

'Heretical' ecological views must be logical and cogent to merit publication, says Daniel Simberloff

Philosopher Mark Sagoff has published his controversial theses on invasion biology in the American Chronicle of Higher Education and in the house organ of his own Institute for Philosophy and Public Policy. But he has found refereed scientific journals unwilling to print his arguments that nothing is inherently harmful about introduced species as a group and that invasion biologists and conservationists have hyped up threats of biological invasions.

His response -to see a conspiracy -is not unusual, particularly for non-scientists aiming to publish heretic views in the scientific literature. Also standard fare is his reasoning for the resistance of so many scientists to his ideas -it results not from weaknesses in his data or arguments, nor from scientists' stated concerns (ecological and economic damage), but from conscious or subconscious psychological factors (aesthetics and perhaps xenophobia). Finally, Sagoff uses a routine rhetorical device -he erects a man of straw.

Here the straw man is Sagoff's assumption that invasion biologists see introduced species as generically bad. They make no such claim, and major policy documents based on their research (such as article 8h of the Rio Biodiversity Convention) explicitly target only introduced species that may cause damage, which scientists recognise as a minority.

That Sagoff is not blacklisted -that is, he could publish in scientific journals if his arguments stood up -is demonstrated by the series of scientific publications by Mark Davis, a biologist who also contends that threats posed by introduced species are overblown. His views remain those of a small minority of scientists but, with his co-authors, he has presented them with sufficiently robust logic and enough data that they have passed muster with experts.

It is noteworthy that Davis shares key rhetorical devices with Sagoff. He, too, erects a straw man -that ecologists claim competition from introduced species threatens biodiversity. In fact, even early research on introduced species recognised that competition between species has much less effect than their feeding patterns or their impact on habitat.

Like Sagoff, Davis searches for covert psychological reasons why invasion biologists do not adopt his views. He says they "reveal their feelings" by the nature of the metaphors they choose: for example, Charles Elton, the British ecologist revered as the founder of the field, was motivated by his wartime fear of German invasion and used martial metaphors. In short, both Sagoff and Davis propose a social construction of invasion biology.

It is nothing new that a tiny minority of scientists (and non-scientists) should get disproportionate press coverage. That such individuals can influence policy is also unsurprising. One need only think of the US response to global climate change that ostensibly rests on "scientific uncertainty" about whether it will happen.

The introduced species issue in the US is similarly politicised, with an administration that sees free trade as the solution to all ills and is hesitant to impede movement of species or products on which species might hitchhike. Further, powerful industries have opposed measures to hinder the arrival of invasive species.

Mainstream scientists can do little to prevent this problem. Certainly, they should not blacklist iconoclasts simply because they are dissidents - and invasion biologists do not. Rather, a steady stream of high-quality research, plus a willingness to explicate results for the media and policymakers, is the best response.

In invasion biology, this is happening, and it will lead to better policy in the long run.

Daniel Simberloff is an ecologist at the University of Tennessee (Knoxville) and is on the editorial board of Biological Invasions as well as a number of other journals with an ecological and/or conservation biological focus.