- Email: [email protected]
A cultured debate
Update Tethys Sea during the earlier Jurassic. Hence, they are but one example of subterranean faunas surviving from ‘deep time’. Today, subterranean faunas are at risk from global warming, hydrologic alteration and pollution, quarrying of host rocks and human visitors. The authors provide a useful overview of these various threats in relation to the rarity and vulnerability of subterranean species. Increased extraction of groundwater, and its pollution by the deadly cocktails of dense nonaqueous phase liquids (DNAPL) has had major impacts on aquatic faunas globally. Diversion of surface waters for irrigation and domestic water supply has also impacted on cave biologies. Sadly, when new caves are discovered, the biology is often the first element to suffer profound impact through trampling, unless minimal impact caving guidelines are followed. The challenge for
Trends in Ecology and Evolution Vol.24 No.10
cave biologists in this century is to develop adequate methods of assessing rarity, realistic models of reserve design and effective monitoring strategies to preserve a diverse and poorly known component of global biodiversity. This well-illustrated book surveys a range of scientific literature on the cryptic and rare species of subterranean habitats. As such, it will find ready acceptance among academic researchers and senior undergraduate students. Because it is written in a clear and engaging style, it will also be of great use to the large body of professional cave managers and protected area managers around the world. If you are only going to buy one book on cave biology, then this is the one to have. 0169-5347/$ – see front matter ß 2009 Elsevier Ltd. All rights reserved. doi:10.1016/j.tree.2009.06.003 Available online 10 August 2009
Book Review
A cultured debate The Question of Animal Culture edited by Kevin N. Laland and Bennett G. Galef. Harvard University Press, 2009. US$49.95/£36.95 hbk (360 pages) ISBN 13: 978 0 674 03126 5.
Michael Kru¨tzen Anthropological Institute and Museum, University of Zurich, Winterthurerstr. 190, 8057 Zurich, Switzerland
Over the past few years, an apparent divide appears to have arisen among researchers studying animal culture, broadly defined as socially transmitted information or innovations that are stable over multiple generations. Apart from a few minor skirmishes fought, for instance, over definitions of culture, two major battlegrounds appear to have emerged. First, do comparative data from longitudinal primate and cetacean studies (e.g. Refs [1–3]) show unequivocally that animal cultures are a widespread phenomenon? And second, if this is the case, could the occurrence of culture, especially in primates, serve as a model to explain the more fully developed cultures in humans? Although these matters have been debated (e.g. Refs [4–6]), it seems that only small steps have been taken towards their resolution. As a consequence, Kevin Laland and Ben Galef have assembled a range of both advocates and sceptics to address The Question of Animal Culture, and their book provides a helpful, albeit not definitive, contribution to this debate. The aim of the book was to ‘capture the current breadth of opinion and to get to the heart of the issues’. Undeniably, the editors have been successful with the former, although an inclusion of a larger number of social anthropologists might have provided a more detailed overview on issues to which biologists usually turn a blind eye. Yet, having finished The Question of Animal Culture, I am left with the vague unease that the debate remains, and that more Corresponding author: Kru¨tzen, M. ([email protected]).
530
empirical data and theoretical inputs are needed. Thus, the book provides yet another, albeit significant, stepping stone towards appeasement. Some chapters (e.g. by van Schaik, Whitehead, and Laland et al.) in particular break new ground in that they provide analytical methods that might enable empirical studies to be successful. Being faced with gathering appropriate data from wild great apes and cetaceans to address the question of animal culture myself, I found these chapters particularly helpful. The Question of Animal Culture starts out with a brief yet comprehensive summary of the animal cultures debate, followed by an introduction of arguments that have been put forward by either side. This sets the scene for contributions from biological anthropologists, primatologists, as well as evolutionary biologists and psychologists, most of whom have made significant contributions to the field. The individual chapters are organised sequentially from the strongest advocates of animal culture to the strongest sceptics. Incidentally, this seems to reflect fairly well the nature of the work: most field workers appear to have a positive attitude towards animal culture, whereas those undertaking controlled experimental work in captivity are generally more sceptical. I wonder whether this is a mere coincidence, yet feel that most contributors are fairly comfortable with the least common denominator that social learning through imitation does have a much larger role in non-humans than was previously thought. The strongest scepticism is expressed by Hill in one of the last chapters. He argues that animals do not show ‘socially learned law, ethics, rituals, religion or morality [...]’, which
Update he deems universal and crucial for human culture. He claims that animals behave like ‘psychopaths’ in that they show no remorse, empathy, anxiety, or guilt. This latter statement flies in the face of much modern primate biology, although there are no doubt interesting differences that need to be mapped more carefully, rather than assumed. Sterelny, in the last chapter, recognises ‘the complaint (by some contributors of this volume) that as soon as an apparently distinctive human capacity is found not be distinctive after all, it ceases to count as a criterion of culture’. I concur, and see it as a positive sign, as cleverly designed experiments and impressive longitudinal datasets seem to be constantly refining the mapping of these boundaries. What remains to be done? Studying the interactions between the three main sources of geographic variation in behaviour (genetic predispositions, ecological conditions and social transmission of innovations) in nature is a priority. Having established that observational forms of social learning have a role in geographic variation in great ape behaviour, how do we estimate its relative importance? Of all suggestions put forward in the book, two are most promising. First, a cultural approach requires that the behavioural variants begin as rare innovations – an assumption that should now be tested with naı¨ve animals in captivity [7]. Second, correlations between pairs of animals (of the same or different populations) in their repertoires of behavioural variants can be used to reveal the relative importance of genetic similarity, ecological overlap or social association. Future work on animal culture would benefit from rigorously addressing ecological and genetic factors. That kind of data will be available soon
Trends in Ecology and Evolution
Vol.24 No.10
for great apes and cetaceans, and will undoubtedly move the debate forward. On an ultimate level, culture can only have lasting evolutionary consequences if it leaves a genetic legacy behind, for instance, trait changes occurring potentially as a result of interactions of organisms with their environment. The book does not cover these aspects of cultural evolution at all, but perhaps the time is not yet ripe. With the advent of new genomic tools, such as nextgeneration sequencing, decoupling variation in behaviour caused by genetic selection and drift from that generated through social learning might become a realistic target on a much finer scale. With these exciting developments at hand, I hope that Laland and Galef can entitle their next collaborative effort ‘The Answers to Animal Culture Questions’. References 1 Whiten, A. et al. (1999) Culture in chimpanzees. Nature 399, 682–685 2 van Schaik, C.P. et al. (2003) Orangutan cultures and the evolution of material culture. Science 299, 102–105 3 Kru¨tzen, M. et al. (2005) Cultural transmission of tool use in bottlenose dolphins. Proc. Natl. Acad. Sci. U. S. A. 102, 8939–8943 4 Laland, K.N. and Janik, V.M. (2006) The animal cultures debate. Trends Ecol. Evol. 21, 542–547 5 Kru¨tzen, M. et al. (2007) The animal cultures debate: response to Laland and Janik. Trends Ecol. Evol. 22, 6–16 6 Fragaszy, D.M. and Perry, S., eds (2003) The Biology of Traditions. Models and Evidence, Cambridge University Press, (Cambridge, UK) 7 van Schaik, C.P. et al. (2006) Innovation in wild Bornean orangutans (Pongo pygmaeus wurmbii). Behaviour 143, 839–876 0169-5347/$ – see front matter ß 2009 Elsevier Ltd. All rights reserved. doi:10.1016/j.tree.2009.06.004 Available online 10 August 2009
Book Review
Snaking through primate evolution The Fruit, the Tree, and the Serpent: Why We See So Well by Lynne A. Isbell. Harvard University Press, 2009. US$45.00/£33.95 hbk (224 pages) ISBN 13: 978 0 674 03301 6
Alison K. Surridge Department of Zoology, University of Cambridge, Downing Street, Cambridge, CB2 3EJ, UK
Adaptations that have occurred throughout the course of primate evolution and those that are ultimately thought to ‘make us human’ hold a fascination for many. Tool use, language, large brain size and enhanced visual acuity are among such traits that are studied extensively by anthropologists, but it is the latter that is the focus of The Fruit, the Tree, and the Serpent. The author’s research interests in social dispersal led her to the discovery that Asian primates have a retrovirus closely related to that carried by the venomous Russell’s viper [1], indicating a shared antagonistic history. So began a ten-year investigation into Corresponding author: Surridge, A.K. ([email protected]).
the influence of snakes on primate evolution in general and primate visual adaptations in particular. For many people, snakes evoke irrational feelings of fear, despite having no previous negative experiences. Among primates, humans are not unique in this response. Winding its way through the central thesis of The Fruit, the Tree, and the Serpent is the ‘snake detection theory,’ which argues that our morbid fascination with snakes and their prominence in religion and folklore is a consequence of a long evolutionary history of predation. It is an interesting concept that a fear of snakes and an ability to react rapidly to them was hard-wired into our neural circuitry early in primate evolution. Isbell argues that selection by snakes as predators lead to a large number of neural and visual adaptations and (rather tenuously) might even have led to the origins of pointing and language. The theory is a 531
Trends in Ecology and Evolution Vol.24 No.10
cave biologists in this century is to develop adequate methods of assessing rarity, realistic models of reserve design and effective monitoring strategies to preserve a diverse and poorly known component of global biodiversity. This well-illustrated book surveys a range of scientific literature on the cryptic and rare species of subterranean habitats. As such, it will find ready acceptance among academic researchers and senior undergraduate students. Because it is written in a clear and engaging style, it will also be of great use to the large body of professional cave managers and protected area managers around the world. If you are only going to buy one book on cave biology, then this is the one to have. 0169-5347/$ – see front matter ß 2009 Elsevier Ltd. All rights reserved. doi:10.1016/j.tree.2009.06.003 Available online 10 August 2009
Book Review
A cultured debate The Question of Animal Culture edited by Kevin N. Laland and Bennett G. Galef. Harvard University Press, 2009. US$49.95/£36.95 hbk (360 pages) ISBN 13: 978 0 674 03126 5.
Michael Kru¨tzen Anthropological Institute and Museum, University of Zurich, Winterthurerstr. 190, 8057 Zurich, Switzerland
Over the past few years, an apparent divide appears to have arisen among researchers studying animal culture, broadly defined as socially transmitted information or innovations that are stable over multiple generations. Apart from a few minor skirmishes fought, for instance, over definitions of culture, two major battlegrounds appear to have emerged. First, do comparative data from longitudinal primate and cetacean studies (e.g. Refs [1–3]) show unequivocally that animal cultures are a widespread phenomenon? And second, if this is the case, could the occurrence of culture, especially in primates, serve as a model to explain the more fully developed cultures in humans? Although these matters have been debated (e.g. Refs [4–6]), it seems that only small steps have been taken towards their resolution. As a consequence, Kevin Laland and Ben Galef have assembled a range of both advocates and sceptics to address The Question of Animal Culture, and their book provides a helpful, albeit not definitive, contribution to this debate. The aim of the book was to ‘capture the current breadth of opinion and to get to the heart of the issues’. Undeniably, the editors have been successful with the former, although an inclusion of a larger number of social anthropologists might have provided a more detailed overview on issues to which biologists usually turn a blind eye. Yet, having finished The Question of Animal Culture, I am left with the vague unease that the debate remains, and that more Corresponding author: Kru¨tzen, M. ([email protected]).
530
empirical data and theoretical inputs are needed. Thus, the book provides yet another, albeit significant, stepping stone towards appeasement. Some chapters (e.g. by van Schaik, Whitehead, and Laland et al.) in particular break new ground in that they provide analytical methods that might enable empirical studies to be successful. Being faced with gathering appropriate data from wild great apes and cetaceans to address the question of animal culture myself, I found these chapters particularly helpful. The Question of Animal Culture starts out with a brief yet comprehensive summary of the animal cultures debate, followed by an introduction of arguments that have been put forward by either side. This sets the scene for contributions from biological anthropologists, primatologists, as well as evolutionary biologists and psychologists, most of whom have made significant contributions to the field. The individual chapters are organised sequentially from the strongest advocates of animal culture to the strongest sceptics. Incidentally, this seems to reflect fairly well the nature of the work: most field workers appear to have a positive attitude towards animal culture, whereas those undertaking controlled experimental work in captivity are generally more sceptical. I wonder whether this is a mere coincidence, yet feel that most contributors are fairly comfortable with the least common denominator that social learning through imitation does have a much larger role in non-humans than was previously thought. The strongest scepticism is expressed by Hill in one of the last chapters. He argues that animals do not show ‘socially learned law, ethics, rituals, religion or morality [...]’, which
Update he deems universal and crucial for human culture. He claims that animals behave like ‘psychopaths’ in that they show no remorse, empathy, anxiety, or guilt. This latter statement flies in the face of much modern primate biology, although there are no doubt interesting differences that need to be mapped more carefully, rather than assumed. Sterelny, in the last chapter, recognises ‘the complaint (by some contributors of this volume) that as soon as an apparently distinctive human capacity is found not be distinctive after all, it ceases to count as a criterion of culture’. I concur, and see it as a positive sign, as cleverly designed experiments and impressive longitudinal datasets seem to be constantly refining the mapping of these boundaries. What remains to be done? Studying the interactions between the three main sources of geographic variation in behaviour (genetic predispositions, ecological conditions and social transmission of innovations) in nature is a priority. Having established that observational forms of social learning have a role in geographic variation in great ape behaviour, how do we estimate its relative importance? Of all suggestions put forward in the book, two are most promising. First, a cultural approach requires that the behavioural variants begin as rare innovations – an assumption that should now be tested with naı¨ve animals in captivity [7]. Second, correlations between pairs of animals (of the same or different populations) in their repertoires of behavioural variants can be used to reveal the relative importance of genetic similarity, ecological overlap or social association. Future work on animal culture would benefit from rigorously addressing ecological and genetic factors. That kind of data will be available soon
Trends in Ecology and Evolution
Vol.24 No.10
for great apes and cetaceans, and will undoubtedly move the debate forward. On an ultimate level, culture can only have lasting evolutionary consequences if it leaves a genetic legacy behind, for instance, trait changes occurring potentially as a result of interactions of organisms with their environment. The book does not cover these aspects of cultural evolution at all, but perhaps the time is not yet ripe. With the advent of new genomic tools, such as nextgeneration sequencing, decoupling variation in behaviour caused by genetic selection and drift from that generated through social learning might become a realistic target on a much finer scale. With these exciting developments at hand, I hope that Laland and Galef can entitle their next collaborative effort ‘The Answers to Animal Culture Questions’. References 1 Whiten, A. et al. (1999) Culture in chimpanzees. Nature 399, 682–685 2 van Schaik, C.P. et al. (2003) Orangutan cultures and the evolution of material culture. Science 299, 102–105 3 Kru¨tzen, M. et al. (2005) Cultural transmission of tool use in bottlenose dolphins. Proc. Natl. Acad. Sci. U. S. A. 102, 8939–8943 4 Laland, K.N. and Janik, V.M. (2006) The animal cultures debate. Trends Ecol. Evol. 21, 542–547 5 Kru¨tzen, M. et al. (2007) The animal cultures debate: response to Laland and Janik. Trends Ecol. Evol. 22, 6–16 6 Fragaszy, D.M. and Perry, S., eds (2003) The Biology of Traditions. Models and Evidence, Cambridge University Press, (Cambridge, UK) 7 van Schaik, C.P. et al. (2006) Innovation in wild Bornean orangutans (Pongo pygmaeus wurmbii). Behaviour 143, 839–876 0169-5347/$ – see front matter ß 2009 Elsevier Ltd. All rights reserved. doi:10.1016/j.tree.2009.06.004 Available online 10 August 2009
Book Review
Snaking through primate evolution The Fruit, the Tree, and the Serpent: Why We See So Well by Lynne A. Isbell. Harvard University Press, 2009. US$45.00/£33.95 hbk (224 pages) ISBN 13: 978 0 674 03301 6
Alison K. Surridge Department of Zoology, University of Cambridge, Downing Street, Cambridge, CB2 3EJ, UK
Adaptations that have occurred throughout the course of primate evolution and those that are ultimately thought to ‘make us human’ hold a fascination for many. Tool use, language, large brain size and enhanced visual acuity are among such traits that are studied extensively by anthropologists, but it is the latter that is the focus of The Fruit, the Tree, and the Serpent. The author’s research interests in social dispersal led her to the discovery that Asian primates have a retrovirus closely related to that carried by the venomous Russell’s viper [1], indicating a shared antagonistic history. So began a ten-year investigation into Corresponding author: Surridge, A.K. ([email protected]).
the influence of snakes on primate evolution in general and primate visual adaptations in particular. For many people, snakes evoke irrational feelings of fear, despite having no previous negative experiences. Among primates, humans are not unique in this response. Winding its way through the central thesis of The Fruit, the Tree, and the Serpent is the ‘snake detection theory,’ which argues that our morbid fascination with snakes and their prominence in religion and folklore is a consequence of a long evolutionary history of predation. It is an interesting concept that a fear of snakes and an ability to react rapidly to them was hard-wired into our neural circuitry early in primate evolution. Isbell argues that selection by snakes as predators lead to a large number of neural and visual adaptations and (rather tenuously) might even have led to the origins of pointing and language. The theory is a 531