- Email: [email protected]
Reindeer on South Georgia: The ecology of an introduced population
TREE vol. 4, no. IO, October
1989
to view the correlation of multilocus heterozygosity with growth in bivalves as evidence for single locus heterosis (while noting that this is not the only interpretation). Not surprisingly, there is more room for argument on topics for which experimental data are few or lacking. Maynard Smith is dubious about the role of peak shifts in speciation, and about the macroevolutionary hypotheses - punctuated equilibrium and species selection that, some argue, flow from this hypothesis. But even though epistatic differences between species do not necessarily imply peak shifts, I do not see why these should be viewed as ‘atypical genetic events’ (p. 2801, given the evidence from fixation of underdominant chromosomes that adaptive valleys are indeed crossed rather often (p. 182). I am not sure who, among the advocates of punctuated equilibrium, supposes that morphological transitions between species are ‘effectively instantaneous and nonadaptive’ (p. 290); Eldredge and Gould’, at least, held that ‘speciation occurs in peripheral isolates by adaptation to
local conditions and the perfection of isolating mechanisms’. These authors and Stanley* argued that long-term morphological trends are due to differential rates of speciation or extinction in lineages with different characters, which Stanley* termed ‘species selection’. Maynard Smith (like some other authors) restricts this term to species-level characters (although he does not explicitly apply such a restriction to group selection), and concludes that because there are few such characters, species selection is largely irrelevant to most morphological evolution. Given his definition of species selection, this is probably true, but his conclusion trivializes what I think is an important distinction between the differential ‘success’ of individual organisms and species. Whether one chooses to call it species selection or not, the longterm trends in horse morphology cannot be understood without reference to the extinction of browsing clades and the persistence of grazing forms, and this, I believe, is qualitatively different from individual selection. As I have indicated elsewhere,
in developing an alternative view of the role in of speciation macroevolution3,4, I share Maynard Smith’s skepticism regarding the mechanisms proposed for punctuated equilibria; but I do think that punctuationist arguments should be portrayed accurately. These, however, are almost the only points on which I have even slight reservation in this excellent and very useful book.
Douglas J. Futuyma Dept of Ecology and Evolution, State University of New York, Stony Brook, NY 11794-5245, USA
Refsnnces 1 Eldredge, N. and Gould, S.J. (1972) in Models in Paleobiology (Schopf, T.J.M., ed.), pp. 82-l 15, Freeman, Cooper&Co. (seep. 111) 2 Stanley, SM. (1975) Proc. NatlAcad.
Sci. USA 72,646-650 3 Futuvma, D.J. (1987)
Am. Nat 130, 465-473 4 Futuyma, D.J. (1989) in Speciation and its Consequences (Otte, D. and Endler, J.A., eds), pp. 557-578, Sinauer
IntroducedSpecies The strengths of this book lie in the Reindeeron SouthGeorgia:TheEcologyof an IntroducedPopulation author’s extensive and thorough research of reindeer on South Georgia. Yet the book is far more than the by N. Leader-Williams, Cambridge usual compilation of previously pubUniversity Press (Studies in Polar Relished papers. Drawing on the vast search Series), 1988. f20.00649.50 literature concerning introduced and hbk (xiv + 319 pages) ISBN 0521 native members of Rangifer taran24277 1 dus (reindeer and caribou), the book minutely examines the comparative Monographs in ecology and evolecology of the species. LeaderWilliams’ elegant synthesis provides ution are increasingly published in clear insight into the particular quesseries. Some series focus on advances in a particular scientific field. tions concerning introductions, and Others organize their titles geogeneral questions of ungulate popugraphically; Reindeer on South lation biology. Georgia is the ninth contribution to Such a comparative study is valuStudies in Polar Research. The title of able for many reasons. In particular, the book and the series in which it both caribou and reindeer are an has been published may mislead important source of protein for man and wolves in the mainland Arctic. biologists. While it may be an important contribution to polar reDespite extensive research, the role search, its importance to biologists is of these two predators in the population regulation of Rangifer is unrevealed by the subtitle: The Ecology clear. Even in studies of a single of an Introduced Population. The population, it is not certain whether book is, in many ways, only Rangifer are limited by predation, nominally about reindeer on South hunting or forage availability’,*. Georgia. Leader-Williams uses his Using data from introduced (predstudy of this single population to Leaderpopulations, illustrate broader ecological patterns ator-free) Williams clearly shows that popuconcerned with the introduction of lation regulation in Rangiferdepends alien species. In its extensive dison complex interactions between cussion of the biology and biological food availability, body condition, fecconseqences of introductions, this is undity, disease and predation. While an important book indeed.
a complex conclusion may dismay game managers, it suggests that ‘quick fix’ solutions (such as shooting wolves) may not always lead to rapid growth of caribou populations. The general topic of introductions is important to conservation for two reasons. First, the introduction of mammals can devastate local animal and plant life (e.g. on Hawai?). Secondly, captive breeding followed by attempts at introduction may often be the last hope for an endangered species4. Regarding the devastating effects of introduced species, Leader-Williams offers some hope. At least on some islands of the southern hemisphere, the negative effects (extinction excepted) of introduced species can often be reversed. If attempts to introduce reindeer to southern islands are indicative of the efforts generally required to establish viable populations of introduced (or reintroduced) animals, we can reach two conclusions. The first is that a relatively high percentage of introductions are successful: 50% of all attempts to introduce Rangifer to oceanic islands have succeeded. (Of course, many of the islands offered an unusual habitat -free of disease, predators and competing herbivores.) Leader-Williams’ discussion 315
TREE vol. 4, no. 10, October
of population irruptions and population cycles underscores a second important point: if, as other authors have suggested5, population cycles are allometrically related to body size, the time-scale over which to measure the ‘success’ of a large mammal reintroduction may be on the order of decades. If the strengths of this book are in its scientific rigour and broad scope, its weaknesses are best described as structural. Placed in a series on polar research, the book is at once too specific in its science to be of great interest to the non-biologist, and often too general in its format and presentation to hold the interest of a biologist. To some extent, this deficiency is mitigated by placing the more technical (and, to me, most important) arguments in nested
paragraphs. Nonetheless, being told that ‘the ovary contains many thousands of primordial follicles at birth, but only a few hundred of these develop into primary follicles’ (p. 63) might be appropriate to an introductory text on reproductive biology, but somehow seems superfluous in a monograph. Chapter summaries have also been reduced to nearly meaningless generalizations. Reindeer on South Georgia is a provocative, thoroughly researched and coherently argued book. In his preface, which in the best tradition I read only after reading the book, Leader-Williams clearly states that the two important themes of the book are the comparative ecology of a widely distributed cervid and the population biology of introduced
1989
species. He achieves great success in his discussion of these themes and anyone interested in comparative ecology or animal (re)introductions would do well to read the book. Pity about the title.
Joshua R. Ginsberg DeptofZoology,Universityof Oxford,SouthParks Road,OxfordOX13PS,UK References 1 Bergerud, A.T. and Ballard, W.B. (1988) J. Wild/. Manage. 52,344-357 2 Bergerud, A.T. (1988) Trends Ecol. Evol. 3,6t3-72 3 Vitousek, P.M., Loope, L.L. and Stone, C.P. (1987) Trends Ecol. Evol. 2.224-227 4 Se& U.S. (1986) Int. Zoo Yeaib. 24/25, 174-179 5 Peterson, R.O., Page, R.E. and Dodge, K.M. (1984) Science224,135D-1352
Use and Abuse of Behaviour Biology and Freedom: An Essay on the Implications of Human Ethology
by S.A. Barnett, Cambridge University Press, 1989. f32.50/$39.50 hbk (xiv + 376 pages) ISBN 0 52135316 5 Why should a link between biology and the concept of freedom exist? Why not between physics and freedom, or geology and freedom? These areas of science may have contributed more to human welfare or risk of extermination (nuclear power, fossil fuels), but few disciplines other than the sweeping term ‘Biology’ are consistently viewed as a major philosophical issue. Biology and Freedom does not really address this question; rather, through elegant prose and slightly outdated examples, it seeks to show the historical and modern misuse of biological, or more specifically behavioural, concepts when applied to our own species. However, the fundamental question of the biological basis of human nature remains unresolved in this book. Barnett, a renowned zoologist and ethologist, accepts that humans are indeed ‘of nature’, organisms operating under biological rules, until we arrive at consciousness, behavioural diversity, or ‘culture’. One trend with respect to humanity emphasizes the ‘human/animal’separation, using components of culture (e.g. Ref. I) - linguistic capacities, tool use and manufacture, reflexive and self consciousness, and societal diversity2. This approach, strongly advocated by Barnett, retains the essential distinction between man
316
and the world he exploits. To blur this distinction would place the exploitative potential of humans at risk, since we could no longer view utilization of other living creatures or resources as outside moral preceptss. Justifiable criticisms4,5 can be leveled at biologists, ethologists and anthropologists who, sometimes through unthinking or sloppy use of human language and sometimes deliberately, see continuities between all behaviour, human and animal.
Obviously, neither complete rejection nor uncritical acceptance of biological concepts is very useful in philosophical debates on the nature of human behaviours. A far more interesting case can be made for exploring how diversity of behaviour is produced in animals as well as humans. One recent focus in behavioural ecology is on principles influencing variability in animal behaviour and societies, not the reductionist determinism so criticized in this book. I was surprised that Bar-
nett, as an ethologist, was willing to state that ‘baboons behave . .I, ignoring the factors influencing the expression of one behaviour out of a range of potential types that may be as complex for baboons as for humans. But such an emphasis has only been developed in the past ten years, and many of the citations in the book to behavioural studies are considerably older. The book is a mixture (at times more of a muddle) of historical perspectives on the issues of man and nature, critiques of popularized behavioural sciences, and genuinely useful approaches to the study of human behaviour. As such, it is at times infuriating, dogmatic and oversimplistic. To reject the theory of natural selection as a tautology when applied to the evolution and function of behaviour needs more serious attention than this book provides. It is relatively easy to dismiss its action on human behaviour when poor examples and out-of-context quotations are jumbled together with extreme statements from the popular press. In darwinian terms, natural selection can only operate through the behaviour of the organism, since this is the interface between the genotype and the environment determining its relative success. It is also easy to lead a naive reader into misunderstandings by confusing the nature of the questions, as in the sections on Homo pugnax, the violent species. Asking questions as to the form of aggression, its causation, its immediate function and its evolutionary origin are all separate issues in ethology7,
1989
to view the correlation of multilocus heterozygosity with growth in bivalves as evidence for single locus heterosis (while noting that this is not the only interpretation). Not surprisingly, there is more room for argument on topics for which experimental data are few or lacking. Maynard Smith is dubious about the role of peak shifts in speciation, and about the macroevolutionary hypotheses - punctuated equilibrium and species selection that, some argue, flow from this hypothesis. But even though epistatic differences between species do not necessarily imply peak shifts, I do not see why these should be viewed as ‘atypical genetic events’ (p. 2801, given the evidence from fixation of underdominant chromosomes that adaptive valleys are indeed crossed rather often (p. 182). I am not sure who, among the advocates of punctuated equilibrium, supposes that morphological transitions between species are ‘effectively instantaneous and nonadaptive’ (p. 290); Eldredge and Gould’, at least, held that ‘speciation occurs in peripheral isolates by adaptation to
local conditions and the perfection of isolating mechanisms’. These authors and Stanley* argued that long-term morphological trends are due to differential rates of speciation or extinction in lineages with different characters, which Stanley* termed ‘species selection’. Maynard Smith (like some other authors) restricts this term to species-level characters (although he does not explicitly apply such a restriction to group selection), and concludes that because there are few such characters, species selection is largely irrelevant to most morphological evolution. Given his definition of species selection, this is probably true, but his conclusion trivializes what I think is an important distinction between the differential ‘success’ of individual organisms and species. Whether one chooses to call it species selection or not, the longterm trends in horse morphology cannot be understood without reference to the extinction of browsing clades and the persistence of grazing forms, and this, I believe, is qualitatively different from individual selection. As I have indicated elsewhere,
in developing an alternative view of the role in of speciation macroevolution3,4, I share Maynard Smith’s skepticism regarding the mechanisms proposed for punctuated equilibria; but I do think that punctuationist arguments should be portrayed accurately. These, however, are almost the only points on which I have even slight reservation in this excellent and very useful book.
Douglas J. Futuyma Dept of Ecology and Evolution, State University of New York, Stony Brook, NY 11794-5245, USA
Refsnnces 1 Eldredge, N. and Gould, S.J. (1972) in Models in Paleobiology (Schopf, T.J.M., ed.), pp. 82-l 15, Freeman, Cooper&Co. (seep. 111) 2 Stanley, SM. (1975) Proc. NatlAcad.
Sci. USA 72,646-650 3 Futuvma, D.J. (1987)
Am. Nat 130, 465-473 4 Futuyma, D.J. (1989) in Speciation and its Consequences (Otte, D. and Endler, J.A., eds), pp. 557-578, Sinauer
IntroducedSpecies The strengths of this book lie in the Reindeeron SouthGeorgia:TheEcologyof an IntroducedPopulation author’s extensive and thorough research of reindeer on South Georgia. Yet the book is far more than the by N. Leader-Williams, Cambridge usual compilation of previously pubUniversity Press (Studies in Polar Relished papers. Drawing on the vast search Series), 1988. f20.00649.50 literature concerning introduced and hbk (xiv + 319 pages) ISBN 0521 native members of Rangifer taran24277 1 dus (reindeer and caribou), the book minutely examines the comparative Monographs in ecology and evolecology of the species. LeaderWilliams’ elegant synthesis provides ution are increasingly published in clear insight into the particular quesseries. Some series focus on advances in a particular scientific field. tions concerning introductions, and Others organize their titles geogeneral questions of ungulate popugraphically; Reindeer on South lation biology. Georgia is the ninth contribution to Such a comparative study is valuStudies in Polar Research. The title of able for many reasons. In particular, the book and the series in which it both caribou and reindeer are an has been published may mislead important source of protein for man and wolves in the mainland Arctic. biologists. While it may be an important contribution to polar reDespite extensive research, the role search, its importance to biologists is of these two predators in the population regulation of Rangifer is unrevealed by the subtitle: The Ecology clear. Even in studies of a single of an Introduced Population. The population, it is not certain whether book is, in many ways, only Rangifer are limited by predation, nominally about reindeer on South hunting or forage availability’,*. Georgia. Leader-Williams uses his Using data from introduced (predstudy of this single population to Leaderpopulations, illustrate broader ecological patterns ator-free) Williams clearly shows that popuconcerned with the introduction of lation regulation in Rangiferdepends alien species. In its extensive dison complex interactions between cussion of the biology and biological food availability, body condition, fecconseqences of introductions, this is undity, disease and predation. While an important book indeed.
a complex conclusion may dismay game managers, it suggests that ‘quick fix’ solutions (such as shooting wolves) may not always lead to rapid growth of caribou populations. The general topic of introductions is important to conservation for two reasons. First, the introduction of mammals can devastate local animal and plant life (e.g. on Hawai?). Secondly, captive breeding followed by attempts at introduction may often be the last hope for an endangered species4. Regarding the devastating effects of introduced species, Leader-Williams offers some hope. At least on some islands of the southern hemisphere, the negative effects (extinction excepted) of introduced species can often be reversed. If attempts to introduce reindeer to southern islands are indicative of the efforts generally required to establish viable populations of introduced (or reintroduced) animals, we can reach two conclusions. The first is that a relatively high percentage of introductions are successful: 50% of all attempts to introduce Rangifer to oceanic islands have succeeded. (Of course, many of the islands offered an unusual habitat -free of disease, predators and competing herbivores.) Leader-Williams’ discussion 315
TREE vol. 4, no. 10, October
of population irruptions and population cycles underscores a second important point: if, as other authors have suggested5, population cycles are allometrically related to body size, the time-scale over which to measure the ‘success’ of a large mammal reintroduction may be on the order of decades. If the strengths of this book are in its scientific rigour and broad scope, its weaknesses are best described as structural. Placed in a series on polar research, the book is at once too specific in its science to be of great interest to the non-biologist, and often too general in its format and presentation to hold the interest of a biologist. To some extent, this deficiency is mitigated by placing the more technical (and, to me, most important) arguments in nested
paragraphs. Nonetheless, being told that ‘the ovary contains many thousands of primordial follicles at birth, but only a few hundred of these develop into primary follicles’ (p. 63) might be appropriate to an introductory text on reproductive biology, but somehow seems superfluous in a monograph. Chapter summaries have also been reduced to nearly meaningless generalizations. Reindeer on South Georgia is a provocative, thoroughly researched and coherently argued book. In his preface, which in the best tradition I read only after reading the book, Leader-Williams clearly states that the two important themes of the book are the comparative ecology of a widely distributed cervid and the population biology of introduced
1989
species. He achieves great success in his discussion of these themes and anyone interested in comparative ecology or animal (re)introductions would do well to read the book. Pity about the title.
Joshua R. Ginsberg DeptofZoology,Universityof Oxford,SouthParks Road,OxfordOX13PS,UK References 1 Bergerud, A.T. and Ballard, W.B. (1988) J. Wild/. Manage. 52,344-357 2 Bergerud, A.T. (1988) Trends Ecol. Evol. 3,6t3-72 3 Vitousek, P.M., Loope, L.L. and Stone, C.P. (1987) Trends Ecol. Evol. 2.224-227 4 Se& U.S. (1986) Int. Zoo Yeaib. 24/25, 174-179 5 Peterson, R.O., Page, R.E. and Dodge, K.M. (1984) Science224,135D-1352
Use and Abuse of Behaviour Biology and Freedom: An Essay on the Implications of Human Ethology
by S.A. Barnett, Cambridge University Press, 1989. f32.50/$39.50 hbk (xiv + 376 pages) ISBN 0 52135316 5 Why should a link between biology and the concept of freedom exist? Why not between physics and freedom, or geology and freedom? These areas of science may have contributed more to human welfare or risk of extermination (nuclear power, fossil fuels), but few disciplines other than the sweeping term ‘Biology’ are consistently viewed as a major philosophical issue. Biology and Freedom does not really address this question; rather, through elegant prose and slightly outdated examples, it seeks to show the historical and modern misuse of biological, or more specifically behavioural, concepts when applied to our own species. However, the fundamental question of the biological basis of human nature remains unresolved in this book. Barnett, a renowned zoologist and ethologist, accepts that humans are indeed ‘of nature’, organisms operating under biological rules, until we arrive at consciousness, behavioural diversity, or ‘culture’. One trend with respect to humanity emphasizes the ‘human/animal’separation, using components of culture (e.g. Ref. I) - linguistic capacities, tool use and manufacture, reflexive and self consciousness, and societal diversity2. This approach, strongly advocated by Barnett, retains the essential distinction between man
316
and the world he exploits. To blur this distinction would place the exploitative potential of humans at risk, since we could no longer view utilization of other living creatures or resources as outside moral preceptss. Justifiable criticisms4,5 can be leveled at biologists, ethologists and anthropologists who, sometimes through unthinking or sloppy use of human language and sometimes deliberately, see continuities between all behaviour, human and animal.
Obviously, neither complete rejection nor uncritical acceptance of biological concepts is very useful in philosophical debates on the nature of human behaviours. A far more interesting case can be made for exploring how diversity of behaviour is produced in animals as well as humans. One recent focus in behavioural ecology is on principles influencing variability in animal behaviour and societies, not the reductionist determinism so criticized in this book. I was surprised that Bar-
nett, as an ethologist, was willing to state that ‘baboons behave . .I, ignoring the factors influencing the expression of one behaviour out of a range of potential types that may be as complex for baboons as for humans. But such an emphasis has only been developed in the past ten years, and many of the citations in the book to behavioural studies are considerably older. The book is a mixture (at times more of a muddle) of historical perspectives on the issues of man and nature, critiques of popularized behavioural sciences, and genuinely useful approaches to the study of human behaviour. As such, it is at times infuriating, dogmatic and oversimplistic. To reject the theory of natural selection as a tautology when applied to the evolution and function of behaviour needs more serious attention than this book provides. It is relatively easy to dismiss its action on human behaviour when poor examples and out-of-context quotations are jumbled together with extreme statements from the popular press. In darwinian terms, natural selection can only operate through the behaviour of the organism, since this is the interface between the genotype and the environment determining its relative success. It is also easy to lead a naive reader into misunderstandings by confusing the nature of the questions, as in the sections on Homo pugnax, the violent species. Asking questions as to the form of aggression, its causation, its immediate function and its evolutionary origin are all separate issues in ethology7,