Guillaume Lecointre Classification Essay

As the book review editor, it is obvious that I would request from the publisher a copy of any book with this title, with the intention of then sending it on to a reviewer. However, I just couldn't make myself do it in this case—I loved the book too much to be able to part with it. So, I am writing the review myself, and all of you will have to buy your own copies.

There are, of course, a number of books around that try to provide an overview of biodiversity, listing the different taxonomic groups, along with an illustrated description of their distinguishing features, the best known being that of Margulis and Schwarz (1997). If nothing else, all introductory biology textbooks also do this, although they never seem to present the other parts of biology in the same style. This is a poor way to explain biodiversity, because it smacks too much of natural history. Natural history is a very valuable thing, as centuries of human study will attest, but it should never be confounded with science. Science is about testing hypotheses, and in our business these hypotheses are about evolutionary history. It has taken biologists a long time to explicate the simple idea that it is the study of biodiversity that makes biology different from other sciences—the nature and scale of the interrelationships among organisms is something that has never been conceived of within physics and chemistry. Evolutionary history is our explanation for the origin of that biodiversity, and so the best way to present biodiversity is in the context of phylogenetic trees. That is what this new book does.

So, what makes this book different is its strictly (almost relentless) phylogenetic perspective. It is based on trees, not only as metaphors but as the primary means of communication—the text and the many excellent line drawings are purely adjuncts to the trees. The book itself is arranged as a set of nested clades, with each section introduced by a tree along with a list of synapomorphies. The clades within that tree then follow on the subsequent pages, presented in the same manner, until the limit of resolution of the book is reached. All of the putatively monophyletic groups are numbered, for ease of locating them within the book, and almost all of them are named. Paraphyly and polyphyly are strictly excluded, no matter how familiar the names of such groups might be.

This book thus demonstrates the art of making something very difficult look surprisingly easy. This is not a feature of all books, because it requires great expertise from the authors, but it would surely be a useful synapomorphy if we could achieve it. In this case, the straightforward arrangement, the simple writing style (translated well) and the direct presentation of phylogenetic information all make the book accessible to the reader, both expert and non-expert alike. In short, the book is unique. It not only represents the first thorough attempt to portray life from a purely phylogenetic perspective, it is an excellent implementation of that idea.

As an added bonus, there is a 35-page introduction to phylogenetic systematics. This is among the best such introductions in any language. The candid and unadorned writing style comes to the fore, so that the ideas and information are comprehensible to the uninitiated without alienating the experts by oversimplification. None of the complications in phylogeny reconstruction are avoided (although the methodology concentrates on parsimony analysis), and yet the concepts are presented in a straightforward and logical manner, with suitable illustrated examples. The strengths and weaknesses of our current methods are presented without excuses, and the consequent classifications are presented without apologies to the traditional approaches. Only long experience in this line of work could produce a synthesis of this type. If you ever need to explain phylogenetic systematics to an interested member of the general public, then you can safely direct them to this essay.

In the main body of the book, the authors have stuck their necks out to produce one set of trees, and thus “a” classification (as the title accurately indicates), rather than taking a more Bayesian view of life and explicitly recognizing uncertainty in phylogeny reconstruction. You will therefore not be hard-pressed to find trees with which you disagree—these are majority-rule trees, not strict-consensus trees. In their favor, they are mostly based on contemporary evidence, so that they reflect current opinion rather than established tradition. On the other hand, the overall impression is given that there is no contention concerning any of the trees, which we all know to be a distorted viewpoint (as do the authors). Nevertheless, the trees have plenty of polychotomies, and even the occasional dashed line, thus showing where we are currently ignorant about relationships.

The authors also do not entertain the notion that the history of life might not be particularly tree-like but may instead be an anastomosing plexus of interrelationships. The latter is certainly not a new idea, especially in microbiology and botany. The conception has even crept into vertebrate biology. However, perhaps it is enough that the authors have dealt so well with trees, without asking them to delve into alternative metaphors such as networks.

Among the most practically useful parts of the book are those appendices entitled “Where are They?” which indicate the position of most of the paraphyletic/polyphyletic common names that still populate the biological literature (algae, coelomates, reptiles, etc). This is a real boon for non-experts in the particular groups concerned, or for those who are too young to have been brought up with the older names (or are too lazy to learn them). Interestingly, the named groups are indicated as either including or not including their most recent common ancestor, so that paraphyly and polyphyly are clearly distinguished from each other.

Most books on biodiversity still subscribe to the Great Chain of Being, with evolutionary advancement proceeding inexorably from bacteria (at the beginning of the book) to human beings (at the end). Phylogeneticists will have no truck with this, however, as all branches on a phylogenetic tree can be rotated ad libitum. So, although bacteria are primal in this book, humans are penultimate, with the ultimate lifeform being ray-finned fishes. This neatly illustrates the fact that “Fishes” is a paraphyletic group and thus fish should not be lumped together. It has taken until the new millennium to get a general-purpose book with a Darwinian-tree view of life rather than an Aristotelian-linear one.

Nevertheless, the thing that will infuriate more readers than anything else is the serious level of imbalance in the treatments of the various clades. For example, the Hexapoda get two pages in the main text and one page in an appendix, whereas the Angiospermae get two pages of main text and four pages of appendix. In even sharper contrast, the Mollusca get 30 pages of main text, and the Vertebrata get more than 150 pages. Although this edition of the book is expanded from previous ones, where the imbalances generated some pointed comments (e.g., Wendel, 2003), the primary expertise of the authors still dominates the information content. The authors justify the imbalance with the claim that they are focusing on “groups that are most important for teaching purposes” (page 7), but that depends very much on what it is that you are teaching. We can hardly claim that we shouldn't be teaching about insects when we are teaching about biodiversity, because they dominate it at the macroscopic level. Only some serious excision of vertebrate taxa would allow the treatments of the other groups to be expanded (the book is large enough as it is).

Although most of the information seems to be accurate, there are, as with any book, errors that will annoy you as well as idiosyncrasies that may dismay you. These include family names are not given initial capitals (contrary to the codes of nomenclature), the page on Arachnida has almost no common names (not even to note that the Acari are ticks and mites), and in an appendix there is the descriptive example “Proteaceae (plane)” (neither aeroplanes, woodworking planes, nor plane trees are in that particular plant family). Among the idiosyncrasies are a sequence alignment that uses hyphens for identical residues and asterisks for gaps (which is the convention in some parts of molecular biology but not in phylogenetics), the failure to mention coccidiosis as a disease caused by Apicomplexans (it is more widespread than the other diseases listed), and some quaint cartoons to illustrate Homo sapiens that are unfortunately all male. Interestingly, the Tree of Life (page 49) remains unrooted, so that technically none of the subsequent trees refer to monophyletic groups!

For some of these quibbles, the authors should be asked to stand in the corner of the classroom, facing the wall, for a couple of hours; after that, they can correct the offending items in the next edition. For future editions there will surely be—there have already been three French editions (2001, 2002, 2006), an Italian edition (2003), and a German one (2005). This first English edition has therefore been long overdue (see Wenzel, 2003).

This is a solidly constructed book that is clearly intended for a long life even when subjected to frequent consultation, which is its purpose. Nevertheless, its undoubted usefulness will ensure that future editions are on the way, with revised and updated classifications. There have already been a number of stylistic changes throughout the editions, notably in the current French and English editions, so that this version is well thought out and very user friendly. All that really needs to happen in the future is for the book to remain up-to-date in a field that prides itself on constant change. So (unlike me), buy yourself a copy, and thus encourage the authors to keep up their good work. You never know, they may even branch out into the multimedia world, as did Margulis and Schwarz (2002).

References

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La classification phylogénétique du vivant

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2001

Paris

Éditions Belin

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La classification phylogénétique du vivant

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2002

2e édition

Paris

Éditions Belin

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La sistematica della vita: Una guida alla classificazione filogenetica

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2003

Zanichelli, Bologna

,  . 

Biosystematik: Alle Organismen im Überblick

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2005

Berlin

Springer-Verlag

,  . 

La classification phylogénétique du vivant

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2006

3e édition

Paris

Éditions Belin

,  . 

Five kingdoms: An illustrated guide to the phyla of life on Earth

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1997

3rd edition (revised)

New York

W.H. Freeman

,  . 

Five kingdoms: A multimedia guide to the phyla of life on Earth (Win/Mac CD-ROM), version 2.0.

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2002

Berlin

Springer-Verlag

© 2007 Society of Systematic Biologists

The Darwinian theory of evolution is itself evolving and this book presents the details of the core of modern Darwinism and its latest developmental directions. The authors present current scientific work addressing theoretical problems and challenges in four sections, beginning with the concepts of evolution theory, its processes of variation, heredity, selection, adaptation and function, and its patterns of character, species, descent and life. 

The second part of this book scrutinizes Darwinism in the philosophy of science and its usefulness in understanding ecosystems, whilst the third section deals with its application in disciplines beyond the biological sciences, including evolutionary psychology and evolutionary economics, Darwinian morality and phylolinguistics. The final section addresses anti-Darwinism, the creationist view and issues around teaching evolution in secondary schools. 

The reader learns how current experimental biology is opening important perspectives on the sources of variation, and thus of the very power of natural selection. This work examines numerous examples of the extension of the principle of natural selection and provides the opportunity to critically reflect on a rich theory, on the methodological rigour that presides in its extensions and exportations, and on the necessity to measure its advantages and also its limits. 

Scholars interested in modern Darwinism and scientific research, its concepts, research programs and controversies will find this book an excellent read, and those considering how Darwinism might evolve, how it can apply to the human sciences and other disciplines beyond its origins will find it particularly valuable.

Originally produced in French (Les Mondes Darwiniens), the scope and usefulness of the book have led to the production of this English text, to reach a wider audience.

This book is a milestone in the impressive penetration by Francophone scholars into the world of Darwinian science, its historiography and philosophy over the last two decades.

Alex Rosenberg, R. Taylor Cole Professor of Philosophy, Duke University

Until now this useful and comprehensive handbook has only been available to francophones. Thanks to this invaluable new translation, this collection of insightful and original essays can reach the global audience it deserves.

Tim Lewens, University of Cambridge

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