- Email: [email protected]
Invasion biology: critique of a pseudoscience
BIOLOGICAL CONSERVATION
Biological Conservation 122 (2005) 505–507 www.elsevier.com/locate/biocon
Book reviews I. David (Ed.), Invasion Biology: Critique of a Pseudoscience, Theodoropoulos, Avvar Books, Blythe, California, 237+xiv pages, ISBN 0-9708504-1-7, Price $14.50 This book falls into the very trap it criticizes: pseudoscientific over-statement of case. I tried to enter it with an open mind, hoping to enjoy reviewing and perhaps disputing a reasoned argument, but the first few pages are so extreme as to put off most readers. However, I read it all, to avoid dismissal by the author (henceforth DIT) as a ‘‘believer’’ who would refuse to do so. While accusing invasion biologists of emotional language, DIT claims that ‘‘invasive species hysteria’’ dominates discourse, due to their ‘‘primal fears’’, and that ‘‘psychological forces’’ are at the root of the invasion biology ‘‘pseudoscience’’, which disregards the data and is ‘‘at odds with the rest of biology’’. Compiling a few of the many adjectives that DIT applies to them, invasion biologists may be troubled to discover that they are extremist, reactionary, xenophobic, racist, fascist, conspiracy theorists, whose work is ‘‘financed by some of the worldÕs most destructive corporations’’. One wonders who is the emotional, hysterical, conspiracy theorist here. Throughout the introduction and Part 1 (the ‘‘evidence’’), DIT quotes out of context and selects examples. He sets up straw men one after the other, proceeding to knock them down, which quickly becomes tiresome. To cite some examples: ‘‘invaded areas are monospecific’’; invaders ‘‘are considered in all cases harmful’’; natural assemblages are the most ‘‘diverse expressions of life possible for a site’’ (island biologists know that is not true). DIT points out, as if it were unrecognised, that many invaders integrate into ecosystems without causing obvious change. Actually, most experts accept this, terming those that do not seem to integrate so benignly ÔtransformersÕ. DIT lists 24 ÔclaimsÕ about invasive species, ‘‘not one of . . . [which] . . . is true’’. Here is one: Ôinvasives are a major threat to endangered speciesÕ. Few scientists would dispute that they are a major cause of extinction on islands (avian malaria and Hawaiian birds; brown tree snake and Guam birds, predatory snails and South Pacific land snails, for example), but few would implicate them as such on continents, yet DIT reveals this distinction as if it were his personal insight (while dismissing island
species as ‘‘doomed to extinction’’ in any case). He admits that in ‘‘rare and isolated habitats such as oceanic islands’’ introduced species may have an effect, but that their effect is impossible to distinguish from that of anthropogenic habitat disturbance. That presumably makes them not worth worrying about. Further, DIT gets these two factors a little confused: on p. 32 he blames disturbance and herbivory by domestic animals for much of what is usually blamed on introduced species, not appearing to realize that the livestock belong among the introduced species he is excusing. Although some of his examples that I do not know personally seem convincing, especially regarding the overwhelming importance of disturbance, those I do know personally are presented in a biased way. For example, the section on ‘‘island fallacies’’ (pp. 51–53), which focuses on my local patch, is indeed full of fallacies. I have never heard a Galapagos scientist say, as DIT writes, that the extinction of the mockingbird on Floreana Island was ‘‘certainly’’ due to introduced cats; we think it possible that cats contributed but have no proof and, as DIT points out, the survival of mockingbirds on other islands with introduced cats is puzzling; we are not blind to the paradox. DIT writes that Galapagos tortoises are ‘‘commonly said to be threatened with extinction by introduced species’’, implying that they are not. We know that past hunting reduced their numbers, but we also know that some of these reduced populations are now prevented from successful reproduction by introduced pigs, rats and fire ants. The tortoises might not be so threatened by these animals if their numbers had not been hunted down, but they will not recover unless we deal with the current threat. DIT also criticizes control of so-called native invaders because such invasions result from anthropogenic habitat change, and implies that those carrying out the control do not know this. On the contrary, British reserve managers controlling scrub on chalk grassland well understand the cause of the invasion (change of grazing regime etc.), but recognise that Britain is almost entirely anthropogenic habitat and choose to maintain a particular habitat type. Nothing new there – another straw man down. Part 2 (nearly one third of the book) contributes little of scientific significance and descends into pseudoscientific psycho-babble, stuffed with false or ridiculous
506
Book reviews / Biological Conservation 122 (2005) 505–507
analogy with Nazism in an attempt to condemn our prejudices, such as: ‘‘the study of biological invasions originated in the Third Reich’’. Part 3Õs thesis is that anthropogenic dispersal increases biodiversity, so should be encouraged. DIT states ‘‘man-aided dispersal can in no way be distinguished from natural dispersal’’ but acknowledges a difference in rate, then immediately dismissing that as unimportant. The Galapagos example is worth exploring: vascular plants established there at about one species every 10,000 years. Since discovery in 1535 some 600 have been introduced by humans and survive to date: 10,000 · the natural rate. Is that important? Not according to DIT, because island endemics are doomed to extinction and Galapagos now has a more diverse flora. Unfortunately, some 20% of its endemics are endangered, the main threat being introduced species. DIT claims eradication of newly established species will stop evolution, which depends on population movements. Again he ignores the difference between the high anthropogenic movement (and extinction) rate and the relatively slow compensation by evolution. He claims global biodiversity will continue to rise, as ‘‘adaptive radiation is promoted by species movement’’. Unfortunately, evolution is not as fast as fossil-fuel-driven transport, so
in the ‘‘short’’ term (the next few hundred thousand years), we just might notice a slight temporary decline in diversity. DIT does make some uncontroversial statements, such as ‘‘the true cause of expanding . . . ÔinvadersÕ is nearly always anthropogenic disturbance’’, or that major invasions often result from other changes such as over-hunting of native predators or herbivores. But these are hardly new observations and they are buried in the polemic. DIT has a valid point, that many invasion ‘‘problems’’ have been overstated. But he commits the same error. The invasives issue may indeed have been over-dramatized, but not to the extent that warrants such an irrational counter-fuss. Happily, science works by logic and eventual consensus, and extremists with little new to contribute are forgotten as the evidence overwhelms their arguments. For that reason, I do not consider this a ‘‘dangerous’’ book, as DIT boasts that it has been called; ‘‘misjudged’’ better sums it up. Alan Tye Botany Department, Charles Darwin Research Station Isla Santa Cruz, Galapagos, Ecuador E-mail address: [email protected]
doi:10.1016/j.biocon.2004.08.003
Handbook of the Birds of the World. Broadbills to Tapaculos, vol. 8. Edited by Josep del Hoyo, Andrew Elliott, David Christie, Lynx Edicions, Barcelona, ISBN 84-87334-50-4, p. 845. Price £120 This is the first volume in the series to describe families of passerine birds and the transition from non-passerines to passerines has not been accompanied by a diminution in quality – Volume 8 is just as stunning as its predecessors. The transition has necessitated some changes in formatting as a result of this volume being the first to take a ÔbiteÕ out of a single taxonomic order, compared with previous volumes that easily accommodated smaller orders in toto. The largest order described in an earlier volume was the Charadriiformes in Volume 3 that contained 18 families, compared with the Passeriformes covered in the current volume that contain nearly 100 families. Volume 8 covers birds almost exclusively of the Neotropics including ovenbirds, woodcreepers, gnateaters, antbirds and tapaculos. The series is revered for its high quality photographs and this volume is no exception, there being 477, accompanied by 81 colour plates and 681 distribution maps. The editors acknowledge the photographersÕ considerable skills in providing images of
poorly known species. Especially stunning are the photographs of the pittas that show the resplendent plumage of, for example, the Rainbow (Pitta iris) and Garnet (Pitta granatina) Pittas. As in previous volumes, photographs are also employed effectively to ÔdescribeÕ behaviours as in the sequence of shots portraying a Bicoloured Antbird (Gymnopithys leucaspsis) and its many postural changes as it forages at the front of an ant swarm. The foreword entitled A Brief History of Classifying Birds by Murray Bruce traces the origins of an avian classification system from Aristotle (382–322 BC) right up to the modern molecular phylogenies based upon DNA–DNA hybridization techniques (e.g. Sibley and Ahlquist, 1990). Bruce takes us on an interesting journey through over two millennia of ornithology and en route he describes the contribution of many familiar individuals who helped shape our understanding of the class Aves. Their names persist to the present day, either in the common names (e.g. Franc¸ois Levaillant, William Swainson, Coenraad Jacob Temminck) or as scientific authorities (e.g. John Latham, Carl Linnaeus, Louis Jean Pierre Vieillot) of species. Inevitably, with a series that already comprises eight volumes, each book has been eagerly anticipated, raven-
Biological Conservation 122 (2005) 505–507 www.elsevier.com/locate/biocon
Book reviews I. David (Ed.), Invasion Biology: Critique of a Pseudoscience, Theodoropoulos, Avvar Books, Blythe, California, 237+xiv pages, ISBN 0-9708504-1-7, Price $14.50 This book falls into the very trap it criticizes: pseudoscientific over-statement of case. I tried to enter it with an open mind, hoping to enjoy reviewing and perhaps disputing a reasoned argument, but the first few pages are so extreme as to put off most readers. However, I read it all, to avoid dismissal by the author (henceforth DIT) as a ‘‘believer’’ who would refuse to do so. While accusing invasion biologists of emotional language, DIT claims that ‘‘invasive species hysteria’’ dominates discourse, due to their ‘‘primal fears’’, and that ‘‘psychological forces’’ are at the root of the invasion biology ‘‘pseudoscience’’, which disregards the data and is ‘‘at odds with the rest of biology’’. Compiling a few of the many adjectives that DIT applies to them, invasion biologists may be troubled to discover that they are extremist, reactionary, xenophobic, racist, fascist, conspiracy theorists, whose work is ‘‘financed by some of the worldÕs most destructive corporations’’. One wonders who is the emotional, hysterical, conspiracy theorist here. Throughout the introduction and Part 1 (the ‘‘evidence’’), DIT quotes out of context and selects examples. He sets up straw men one after the other, proceeding to knock them down, which quickly becomes tiresome. To cite some examples: ‘‘invaded areas are monospecific’’; invaders ‘‘are considered in all cases harmful’’; natural assemblages are the most ‘‘diverse expressions of life possible for a site’’ (island biologists know that is not true). DIT points out, as if it were unrecognised, that many invaders integrate into ecosystems without causing obvious change. Actually, most experts accept this, terming those that do not seem to integrate so benignly ÔtransformersÕ. DIT lists 24 ÔclaimsÕ about invasive species, ‘‘not one of . . . [which] . . . is true’’. Here is one: Ôinvasives are a major threat to endangered speciesÕ. Few scientists would dispute that they are a major cause of extinction on islands (avian malaria and Hawaiian birds; brown tree snake and Guam birds, predatory snails and South Pacific land snails, for example), but few would implicate them as such on continents, yet DIT reveals this distinction as if it were his personal insight (while dismissing island
species as ‘‘doomed to extinction’’ in any case). He admits that in ‘‘rare and isolated habitats such as oceanic islands’’ introduced species may have an effect, but that their effect is impossible to distinguish from that of anthropogenic habitat disturbance. That presumably makes them not worth worrying about. Further, DIT gets these two factors a little confused: on p. 32 he blames disturbance and herbivory by domestic animals for much of what is usually blamed on introduced species, not appearing to realize that the livestock belong among the introduced species he is excusing. Although some of his examples that I do not know personally seem convincing, especially regarding the overwhelming importance of disturbance, those I do know personally are presented in a biased way. For example, the section on ‘‘island fallacies’’ (pp. 51–53), which focuses on my local patch, is indeed full of fallacies. I have never heard a Galapagos scientist say, as DIT writes, that the extinction of the mockingbird on Floreana Island was ‘‘certainly’’ due to introduced cats; we think it possible that cats contributed but have no proof and, as DIT points out, the survival of mockingbirds on other islands with introduced cats is puzzling; we are not blind to the paradox. DIT writes that Galapagos tortoises are ‘‘commonly said to be threatened with extinction by introduced species’’, implying that they are not. We know that past hunting reduced their numbers, but we also know that some of these reduced populations are now prevented from successful reproduction by introduced pigs, rats and fire ants. The tortoises might not be so threatened by these animals if their numbers had not been hunted down, but they will not recover unless we deal with the current threat. DIT also criticizes control of so-called native invaders because such invasions result from anthropogenic habitat change, and implies that those carrying out the control do not know this. On the contrary, British reserve managers controlling scrub on chalk grassland well understand the cause of the invasion (change of grazing regime etc.), but recognise that Britain is almost entirely anthropogenic habitat and choose to maintain a particular habitat type. Nothing new there – another straw man down. Part 2 (nearly one third of the book) contributes little of scientific significance and descends into pseudoscientific psycho-babble, stuffed with false or ridiculous
506
Book reviews / Biological Conservation 122 (2005) 505–507
analogy with Nazism in an attempt to condemn our prejudices, such as: ‘‘the study of biological invasions originated in the Third Reich’’. Part 3Õs thesis is that anthropogenic dispersal increases biodiversity, so should be encouraged. DIT states ‘‘man-aided dispersal can in no way be distinguished from natural dispersal’’ but acknowledges a difference in rate, then immediately dismissing that as unimportant. The Galapagos example is worth exploring: vascular plants established there at about one species every 10,000 years. Since discovery in 1535 some 600 have been introduced by humans and survive to date: 10,000 · the natural rate. Is that important? Not according to DIT, because island endemics are doomed to extinction and Galapagos now has a more diverse flora. Unfortunately, some 20% of its endemics are endangered, the main threat being introduced species. DIT claims eradication of newly established species will stop evolution, which depends on population movements. Again he ignores the difference between the high anthropogenic movement (and extinction) rate and the relatively slow compensation by evolution. He claims global biodiversity will continue to rise, as ‘‘adaptive radiation is promoted by species movement’’. Unfortunately, evolution is not as fast as fossil-fuel-driven transport, so
in the ‘‘short’’ term (the next few hundred thousand years), we just might notice a slight temporary decline in diversity. DIT does make some uncontroversial statements, such as ‘‘the true cause of expanding . . . ÔinvadersÕ is nearly always anthropogenic disturbance’’, or that major invasions often result from other changes such as over-hunting of native predators or herbivores. But these are hardly new observations and they are buried in the polemic. DIT has a valid point, that many invasion ‘‘problems’’ have been overstated. But he commits the same error. The invasives issue may indeed have been over-dramatized, but not to the extent that warrants such an irrational counter-fuss. Happily, science works by logic and eventual consensus, and extremists with little new to contribute are forgotten as the evidence overwhelms their arguments. For that reason, I do not consider this a ‘‘dangerous’’ book, as DIT boasts that it has been called; ‘‘misjudged’’ better sums it up. Alan Tye Botany Department, Charles Darwin Research Station Isla Santa Cruz, Galapagos, Ecuador E-mail address: [email protected]
doi:10.1016/j.biocon.2004.08.003
Handbook of the Birds of the World. Broadbills to Tapaculos, vol. 8. Edited by Josep del Hoyo, Andrew Elliott, David Christie, Lynx Edicions, Barcelona, ISBN 84-87334-50-4, p. 845. Price £120 This is the first volume in the series to describe families of passerine birds and the transition from non-passerines to passerines has not been accompanied by a diminution in quality – Volume 8 is just as stunning as its predecessors. The transition has necessitated some changes in formatting as a result of this volume being the first to take a ÔbiteÕ out of a single taxonomic order, compared with previous volumes that easily accommodated smaller orders in toto. The largest order described in an earlier volume was the Charadriiformes in Volume 3 that contained 18 families, compared with the Passeriformes covered in the current volume that contain nearly 100 families. Volume 8 covers birds almost exclusively of the Neotropics including ovenbirds, woodcreepers, gnateaters, antbirds and tapaculos. The series is revered for its high quality photographs and this volume is no exception, there being 477, accompanied by 81 colour plates and 681 distribution maps. The editors acknowledge the photographersÕ considerable skills in providing images of
poorly known species. Especially stunning are the photographs of the pittas that show the resplendent plumage of, for example, the Rainbow (Pitta iris) and Garnet (Pitta granatina) Pittas. As in previous volumes, photographs are also employed effectively to ÔdescribeÕ behaviours as in the sequence of shots portraying a Bicoloured Antbird (Gymnopithys leucaspsis) and its many postural changes as it forages at the front of an ant swarm. The foreword entitled A Brief History of Classifying Birds by Murray Bruce traces the origins of an avian classification system from Aristotle (382–322 BC) right up to the modern molecular phylogenies based upon DNA–DNA hybridization techniques (e.g. Sibley and Ahlquist, 1990). Bruce takes us on an interesting journey through over two millennia of ornithology and en route he describes the contribution of many familiar individuals who helped shape our understanding of the class Aves. Their names persist to the present day, either in the common names (e.g. Franc¸ois Levaillant, William Swainson, Coenraad Jacob Temminck) or as scientific authorities (e.g. John Latham, Carl Linnaeus, Louis Jean Pierre Vieillot) of species. Inevitably, with a series that already comprises eight volumes, each book has been eagerly anticipated, raven-