- Email: [email protected]
Nearly everything you might need to know about marine mammals
Update
TRENDS in Ecology and Evolution
organisms. This is demonstrated most spectacularly by the role of the gene Pax-6 and its homologues in the development of eyes within a multitude of phyla whose common ancestor lacked them, and the role of Distalless in the formation of limbs and a diversity of other outgrowths that evolved independently in protostomes and deuterostomes. Much of Wilkin’s book is devoted to the elaboration of the concept of developmental pathways as a means to understand how different body plans were established among multicellular organisms, and how modifications of these pathways have resulted in their continuing evolution. In their simplest form, developmental pathways can be essentially linear, with a particular gene being activated, which influences a series of down-stream genes that together result in processes such as cell differentiation, movement, or adhesion, leading to the development of particular tissues or structures. Changes in the pathway can occur at many levels: the nature and/or sequence of bases in the exons encoding particular polypeptides or proteins, the modification of cis regulatory elements (as emphasized by Carroll et al. [3]), differences in mRNA resulting in different patterns of protein splicing, the introduction of new genes, or even the integration of previously distinct pathways. Examples of changes in developmental pathways are used to explain sex determination, the evolution of segmental patterns in insects, and the origin of the tetrapod limb. Wilkins specifically emphasizes the recruitment (or co-opting) of new genes into previously existing pathways. As an example, he cites the many new structures in vertebrates (e.g. neural crest, paired sensory organs,
Vol.18 No.3 March 2003
111
pharyngeal skeleton, and paired fins) that have evolved through integration of Distalless. While such cases of gene recruitment might have led to the origin of entirely new structures, body plans, and ways of life, changes within the coding region of individual genes, and especially the modification of cis regulatory elements, might be the ultimate source of small-scale, quantitative changes, including those seen in evolution at the population and species level, such as the differences in bill size among the Galapagos finches [6]. In this book, Wilkins shows how increasing knowledge of the elements of inheritance and development has the potential for explaining the underlying molecular basis for all evolutionary change. This opens up a whole new scale of evolutionary phenomena that can be investigated at all taxonomic levels, in all groups of multicellular organisms. References 1 Raff, R.A. (1996) The Shape of Life: Genes, Development, and the Evolution of Animal Form, University of Chicago Press 2 Gehring, J.J. (1998) Master Control Genes in Development and Evolution: The Homeobox Story, Yale University Press 3 Carroll, S. et al. (2001) From DNA to Diversity: Molecular Genetics and the Evolution of Animal Design, Blackwell Science 4 Davidson, E.H. (2001) Genomic Regulatory Systems: Development and Evolution, Academic Press 5 Arthur, W. (1997) The Origin of Animal Body Plans: A Study in Evolutionary Developmental Biology, Cambridge University Press 6 Grant, P.R. (1999) Ecology and Evolution of Darwin’s Finches, Princeton University Press 0169-5347/03/$ - see front matter q 2002 Elsevier Science Ltd. All rights reserved. PII: S0169-5347(02)00037-X
Nearly everything you might need to know about marine mammals Marine Mammal Biology. An Evolutionary Approach edited by A. Rus Hoelzel, Blackwell Science, 2002. £29.95 pbk (x þ 432 pages) ISBN 0 632 05232 5
Ian McLaren Department of Biology, University of Dalhousie, Halifax, Nova Scotia, Canada B3H 4J1
Unqualified ‘biology’ in a book title is ambitious. Marine Mammal Biology reflects the immense expertise of the 25 authors of the 14 chapters in subjects ranging from molecular systematics to cognitive psychology. The book is well integrated, not only by the ‘evolutionary approach’, but also because marine mammalogists often move among disciplines, and hence are given to lateral thinking. For the nonspecialist, there are appropriate boxes about current concepts, methodologies and terminology. Understanding deepens with new methodologies, for example molecular techniques to elucidate geographical, Corresponding author: Ian McLaren ([email protected]). http://tree.trends.com
social and sexual relationships, fatty acid signature analysis to assess recent diets, and attachable instrumentation, such as GPS, time-depth recorders and even miniature camcorders, to follow animals into the hitherto unknown. Some long-disputed issues are discussed. For example, Boyd’s rigorous survey of energetics concludes that small marine mammals operate well above and large ones close to predictions (accordingly unhelpful) of basal metabolic rates for terrestrial mammals, a situation perhaps driven by flipper surface areas. Schusterman and Kastak, acknowledging that ‘proper interpretation…may never be put to rest’, again argue that artificial language skill does not mean innate understanding of syntax per se, but is an extension of widespread (and adaptive) abilities to form equivalence relations. Others argue that some major controversies are not settled, in spite of recent wide
Update
112
TRENDS in Ecology and Evolution
acceptance of singular views. For example, Heyning and Lento conclude that the precise origins of cetaceans and pinnipeds are still obscured in rapid radiations of their broader ancestral groups. Only rarely might one wish that authors had gone a bit further in their assignments. Bowen et al., in considering roles of marine mammals in communities and ecosystems, describe the well documented top-down effects of sea otters and bottom-up effects of El Nin˜o events in the eastern tropical Pacific, without critical assessment of more elaborate approaches [1,2]. In their chapter about life history and reproductive strategies, Boness et al. do not really get far into life-history strategies in the usual sense [3], although they extensively tabulate and discuss the appropriate parameters (except life span, which remains elusive, or even undefined). There are (to me) many novel observations and hypotheses in the book. For example, Dehnhardt describes how a blindfolded harbour seal can use its whiskers to track hydrodynamic trails as long as 40 m. Bowen et al. suggest that sea otters had decoupled a coevolutionary arms race involving algal antifeedants and invertebrate grazing; hence the devastation when sea otters were removed. Boness et al. hypothesize that the prevailing defence on land of territorial boundaries by otariid males and of females by phocid males is related to the poorer mobility of the latter. Marine Mammal Biology ends with a chapter about conservation and management in which the authors believe that ‘answers to the questions of why conservation is important will come at least partly from the normative realm (religion, ethics, etc.) rather than from science alone’.
Vol.18 No.3 March 2003
Surely, though, the largely ‘pure’ science in this book enhances the charisma of these wonderful animals, which should go some way towards aiding their conservation. In short, this book successfully surveys the whole of marine mammal biology. Previous attempts are dated [4] or less sweeping [5], and so I recommend that all marine mammalogists own or at least have access to this book. Biologists distracted by other taxa (birds, fish or primates) might also find inspiration therein. Those with novel technical expertise might look for things to do with seals or cetaceans. It might be too overwhelming for classes in marine mammal biology, for which there are more studentfriendly texts [6]. However, instructors of such classes cannot ignore this book for amplification (and sometimes contradiction) of textbook wisdom. References 1 Bundy, A. (2001) Fishing on ecosystems: the interplay of fishing and predation in Newfoundland – Labrador. Can. J. Fish. Aquat. Sci. 58, 1153 – 1167 2 Yodzis, P. (1998) Local trophodynamics and the interactions of marine mammals and fisheries in the Benguala ecosystem. J. Anim. Ecol. 67, 635 – 658 3 Roff, D.A. (1992) The Evolution of Life Histories, Chapman & Hall 4 (1969) In The Biology of Marine Mammals (Andersen, H.T., ed.), Academic Press 5 (1999) Biology of Marine Mammals (Reynolds, J.E. III, Rommel, S.A. eds), Smithsonian Institution Press 6 Berta, A. and Sumich, J.L. (1999) Marine Mammals: Evolutionary Biology, Academic Press 0169-5347/03/$ - see front matter q 2002 Elsevier Science Ltd. All rights reserved. PII: S0169-5347(02)00042-3
Endeavour
the quarterly magazine for the history and philosophy of science Online access to Endeavour is FREE to BioMedNet subscribers, providing you with a collection of beautifully illustrated articles in the history of science, book reviews and editorial comment. featuring Gardens of paradise by Staffan Mu¨ller-Wille Crookes, carbolic and cattle plague by William H. Brock Benjamin West’s portrait of Joseph Banks by Patricia Fara British cell theory on the eve of genetics by Marsh L. Richmond Humphrey Davy: science and social mobility by David M. Knight Replanting Eden: John Evelyn and his gardens by Sandra Sherman Biochemistry comes of age: a century of endeavour by Keith L. Manchester The ethics of vaccine usage in society: lessons from the past by Herve´ Bazin Genetics, eugenics and the medicalization of social behaviour by Garland E. Allen Artists as scientists: nature and realism in early-modern Europe by Pamela H. Smith Elegant hypothesis and inelegant fact in developmental biology by Nicholas A.M. Monk Exotic abortifacients: the global politics of plants in the 18th century by Londa Shiebinger Designing nature reserves: adapting ecology to real-world problems by Sharon Kingsland Ramo´n y Cajal: a century after the publication of his masterpiece by Pedro J. Andres-Barquin The understanding of monsters at the Royal Society in the 18th century by Palmira F. da Costa and much, much more Locate Endeavour in the extensive BioMedNet Reviews collection. Log on to http://reviews.bmn.com, hit the ‘Browse Journals’ tab and scroll down to Endeavour BOOKMARK TODAY http://tree.trends.com
TRENDS in Ecology and Evolution
organisms. This is demonstrated most spectacularly by the role of the gene Pax-6 and its homologues in the development of eyes within a multitude of phyla whose common ancestor lacked them, and the role of Distalless in the formation of limbs and a diversity of other outgrowths that evolved independently in protostomes and deuterostomes. Much of Wilkin’s book is devoted to the elaboration of the concept of developmental pathways as a means to understand how different body plans were established among multicellular organisms, and how modifications of these pathways have resulted in their continuing evolution. In their simplest form, developmental pathways can be essentially linear, with a particular gene being activated, which influences a series of down-stream genes that together result in processes such as cell differentiation, movement, or adhesion, leading to the development of particular tissues or structures. Changes in the pathway can occur at many levels: the nature and/or sequence of bases in the exons encoding particular polypeptides or proteins, the modification of cis regulatory elements (as emphasized by Carroll et al. [3]), differences in mRNA resulting in different patterns of protein splicing, the introduction of new genes, or even the integration of previously distinct pathways. Examples of changes in developmental pathways are used to explain sex determination, the evolution of segmental patterns in insects, and the origin of the tetrapod limb. Wilkins specifically emphasizes the recruitment (or co-opting) of new genes into previously existing pathways. As an example, he cites the many new structures in vertebrates (e.g. neural crest, paired sensory organs,
Vol.18 No.3 March 2003
111
pharyngeal skeleton, and paired fins) that have evolved through integration of Distalless. While such cases of gene recruitment might have led to the origin of entirely new structures, body plans, and ways of life, changes within the coding region of individual genes, and especially the modification of cis regulatory elements, might be the ultimate source of small-scale, quantitative changes, including those seen in evolution at the population and species level, such as the differences in bill size among the Galapagos finches [6]. In this book, Wilkins shows how increasing knowledge of the elements of inheritance and development has the potential for explaining the underlying molecular basis for all evolutionary change. This opens up a whole new scale of evolutionary phenomena that can be investigated at all taxonomic levels, in all groups of multicellular organisms. References 1 Raff, R.A. (1996) The Shape of Life: Genes, Development, and the Evolution of Animal Form, University of Chicago Press 2 Gehring, J.J. (1998) Master Control Genes in Development and Evolution: The Homeobox Story, Yale University Press 3 Carroll, S. et al. (2001) From DNA to Diversity: Molecular Genetics and the Evolution of Animal Design, Blackwell Science 4 Davidson, E.H. (2001) Genomic Regulatory Systems: Development and Evolution, Academic Press 5 Arthur, W. (1997) The Origin of Animal Body Plans: A Study in Evolutionary Developmental Biology, Cambridge University Press 6 Grant, P.R. (1999) Ecology and Evolution of Darwin’s Finches, Princeton University Press 0169-5347/03/$ - see front matter q 2002 Elsevier Science Ltd. All rights reserved. PII: S0169-5347(02)00037-X
Nearly everything you might need to know about marine mammals Marine Mammal Biology. An Evolutionary Approach edited by A. Rus Hoelzel, Blackwell Science, 2002. £29.95 pbk (x þ 432 pages) ISBN 0 632 05232 5
Ian McLaren Department of Biology, University of Dalhousie, Halifax, Nova Scotia, Canada B3H 4J1
Unqualified ‘biology’ in a book title is ambitious. Marine Mammal Biology reflects the immense expertise of the 25 authors of the 14 chapters in subjects ranging from molecular systematics to cognitive psychology. The book is well integrated, not only by the ‘evolutionary approach’, but also because marine mammalogists often move among disciplines, and hence are given to lateral thinking. For the nonspecialist, there are appropriate boxes about current concepts, methodologies and terminology. Understanding deepens with new methodologies, for example molecular techniques to elucidate geographical, Corresponding author: Ian McLaren ([email protected]). http://tree.trends.com
social and sexual relationships, fatty acid signature analysis to assess recent diets, and attachable instrumentation, such as GPS, time-depth recorders and even miniature camcorders, to follow animals into the hitherto unknown. Some long-disputed issues are discussed. For example, Boyd’s rigorous survey of energetics concludes that small marine mammals operate well above and large ones close to predictions (accordingly unhelpful) of basal metabolic rates for terrestrial mammals, a situation perhaps driven by flipper surface areas. Schusterman and Kastak, acknowledging that ‘proper interpretation…may never be put to rest’, again argue that artificial language skill does not mean innate understanding of syntax per se, but is an extension of widespread (and adaptive) abilities to form equivalence relations. Others argue that some major controversies are not settled, in spite of recent wide
Update
112
TRENDS in Ecology and Evolution
acceptance of singular views. For example, Heyning and Lento conclude that the precise origins of cetaceans and pinnipeds are still obscured in rapid radiations of their broader ancestral groups. Only rarely might one wish that authors had gone a bit further in their assignments. Bowen et al., in considering roles of marine mammals in communities and ecosystems, describe the well documented top-down effects of sea otters and bottom-up effects of El Nin˜o events in the eastern tropical Pacific, without critical assessment of more elaborate approaches [1,2]. In their chapter about life history and reproductive strategies, Boness et al. do not really get far into life-history strategies in the usual sense [3], although they extensively tabulate and discuss the appropriate parameters (except life span, which remains elusive, or even undefined). There are (to me) many novel observations and hypotheses in the book. For example, Dehnhardt describes how a blindfolded harbour seal can use its whiskers to track hydrodynamic trails as long as 40 m. Bowen et al. suggest that sea otters had decoupled a coevolutionary arms race involving algal antifeedants and invertebrate grazing; hence the devastation when sea otters were removed. Boness et al. hypothesize that the prevailing defence on land of territorial boundaries by otariid males and of females by phocid males is related to the poorer mobility of the latter. Marine Mammal Biology ends with a chapter about conservation and management in which the authors believe that ‘answers to the questions of why conservation is important will come at least partly from the normative realm (religion, ethics, etc.) rather than from science alone’.
Vol.18 No.3 March 2003
Surely, though, the largely ‘pure’ science in this book enhances the charisma of these wonderful animals, which should go some way towards aiding their conservation. In short, this book successfully surveys the whole of marine mammal biology. Previous attempts are dated [4] or less sweeping [5], and so I recommend that all marine mammalogists own or at least have access to this book. Biologists distracted by other taxa (birds, fish or primates) might also find inspiration therein. Those with novel technical expertise might look for things to do with seals or cetaceans. It might be too overwhelming for classes in marine mammal biology, for which there are more studentfriendly texts [6]. However, instructors of such classes cannot ignore this book for amplification (and sometimes contradiction) of textbook wisdom. References 1 Bundy, A. (2001) Fishing on ecosystems: the interplay of fishing and predation in Newfoundland – Labrador. Can. J. Fish. Aquat. Sci. 58, 1153 – 1167 2 Yodzis, P. (1998) Local trophodynamics and the interactions of marine mammals and fisheries in the Benguala ecosystem. J. Anim. Ecol. 67, 635 – 658 3 Roff, D.A. (1992) The Evolution of Life Histories, Chapman & Hall 4 (1969) In The Biology of Marine Mammals (Andersen, H.T., ed.), Academic Press 5 (1999) Biology of Marine Mammals (Reynolds, J.E. III, Rommel, S.A. eds), Smithsonian Institution Press 6 Berta, A. and Sumich, J.L. (1999) Marine Mammals: Evolutionary Biology, Academic Press 0169-5347/03/$ - see front matter q 2002 Elsevier Science Ltd. All rights reserved. PII: S0169-5347(02)00042-3
Endeavour
the quarterly magazine for the history and philosophy of science Online access to Endeavour is FREE to BioMedNet subscribers, providing you with a collection of beautifully illustrated articles in the history of science, book reviews and editorial comment. featuring Gardens of paradise by Staffan Mu¨ller-Wille Crookes, carbolic and cattle plague by William H. Brock Benjamin West’s portrait of Joseph Banks by Patricia Fara British cell theory on the eve of genetics by Marsh L. Richmond Humphrey Davy: science and social mobility by David M. Knight Replanting Eden: John Evelyn and his gardens by Sandra Sherman Biochemistry comes of age: a century of endeavour by Keith L. Manchester The ethics of vaccine usage in society: lessons from the past by Herve´ Bazin Genetics, eugenics and the medicalization of social behaviour by Garland E. Allen Artists as scientists: nature and realism in early-modern Europe by Pamela H. Smith Elegant hypothesis and inelegant fact in developmental biology by Nicholas A.M. Monk Exotic abortifacients: the global politics of plants in the 18th century by Londa Shiebinger Designing nature reserves: adapting ecology to real-world problems by Sharon Kingsland Ramo´n y Cajal: a century after the publication of his masterpiece by Pedro J. Andres-Barquin The understanding of monsters at the Royal Society in the 18th century by Palmira F. da Costa and much, much more Locate Endeavour in the extensive BioMedNet Reviews collection. Log on to http://reviews.bmn.com, hit the ‘Browse Journals’ tab and scroll down to Endeavour BOOKMARK TODAY http://tree.trends.com