Outside Eye on the Hominid Beat How Green Was the Devonian Valley?

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_7111______BOOK REVIEWS------_:..::NA~JU~RE==-V:...=O=L.~31::...2::.:20/:...=27:...:DECEMBER==::.::...:'=984 sal; Neogene climates and geology; evolu balance, but the descriptive part of the Outside eye on the tionary theory; molecular-based phylo book is unduly biased towards North genies; taphonomy; ecological theory and American and western European species. hominid beat more. Lewin also steers a clear and even Past research was indeed more or less handed course through such contentious confined to these areas, but Devonian Leonard Krishtalka issues as phyletic gradualism versus punc floras have been recorded from the Soviet Human Evolution: An Dlustrated tuated equilibrium, molecular versus Union since the 1950s, and there has Introduction. palaeontological divergence clocks, the recently been considerable interest in By Roger Lewin. status of Australopithecus ajarensis, socio China. The resulting descriptions are Blackwell Scientific/W.H. Freeman: biology and so on. usually brief, but in some instances more 1984. Pp.104. Hbk $22.36; pbk £6.80, This is not a personal work. Lewin is the could have been added at least for floristic comparisons; for example, no mention is $14.95. journalist throughout, reporting the con sensus and disagreements, and deferring in made of the important genus Arch most instances to the conclusions of the aeopteris occurring in China. Also, in PALAEOANTHROPOLOGY is familiar terrain principal investigators in each field. And my opinion the authors have not placed to Roger Lewin. With Richard Leakey, he the presentation is balanced: comprehen enough importance on dispersed spores in wrote Origins and People of the Lake, and sive yet concise, not overly technical for the the interpretation of Devonian floras. he regularly covers the hominid beat, general reader yet meaty enough for most Reference is made to them only in passing among other subjects, for Science. Not students of human origins. The index is in the discussion of heterospory, and in the surprisingly, Human Evolution: An lllu detailed and the selected bibliography ade in situ spore studies, yet the sculptute and strated Introduction is a testament to quate. construction in certain dispersed spores Lewin's expertise at science journalism. My one quibble concerns the illustra can confidently be used to give further The writing is deft, the science lucid and the tions. They complement and supplement information on age and geographic distri attitude no-nonsense. the text, but curiously are not numbered; butions of floras. Similarly, the section on All of the main characters in palaeo nowhere are they tied to the written Devonian floras is too short with the anthropology are here - Aegyptopithe material. Although most of the figures ap Middle Devonian landscape restricted to cus, Ramapithecus, Sivapithecus, the pear near the appropriate text, the usual in less than a page. australopithecines and Homo - along text references to figure so and so would There are other points worth question with the basic plot: the origin and evolution have been helpful. Also, a few of the figure ing. The authors refer to Cooksonia as the of hominids, bipedalism, large brain size, captions could be more explanatory, only undoubted vascular plant found in the tool technology and social structures. especially for those illustrations taken from Late Silurian, but the evidence is not con Lewin ties the fossil record, morphology technical research papers. clusive that Cooksonia is a vascular plant. and, as appropriate, the archaeology of the Over the past few years palaeoanthro Even less so is Steganotheca, which they various taxa to reconstructions of their evo pology has matured into a vigorous multi include within the vascular family Rhyni lutionary relationships, palaeoecology and disciplinary science. Lewin's Human aceae, though earlier they mention it within cultural adaptations. This core informa Evolution is a concise primer on the subject the possible vascular plants. Why, one tion occupies only 70 or so of the 99 pages. which a wide variety of readers will find wonders, aren't Rhynia gwynne-vaughanii The remainder are devoted to first prin rewarding. D and Rhynia major given separate treat ciples and to the auxiliary disciplines that ment, rather than being lumped under Leonard Krishtalka is Associate Curator in the impinge on hominid palaeontology: high Section of Vertebrate Fossils, Carnegie Rhynia, for the "xylem" of R. major is lights of the evolution of life on Earth; Museum ofNatural History, Pittsburgh, Penn clearly very different from that in R. primate origins, diversification and disper- sylvania. gwynne-vaughanii? Baragwanathia longi folia is included in the section on Lower and Middle Devonian fossils, when Devonian. All the ensuing activity was evidence now suggests that the lower How green was the reflected in the enormous increase in Baragwanathia horizon is Upper Silurian species described, particularly during the (to be fair, this latest dating may have been Devonian valley? past 25 years. But while books have published after the book went to press). It appeared recently on both Precambrian would, too, have been preferable for the Keith Allen life and angiosperm origins, one or two descriptions of the rhyniophytes to have Plant Life in the Devonian. brief summaries apart there has been preceded rather than followed the trimero By Patricia G. Gensel and Henry N. nothing on Devonian floras. This new phytes; after all, they are less complex, and Andrews. volume by Gensel and Andrews partly it seems likely that they gave rise to the Praeger ..· 1984. Pp.380. $29.95, £32.95. satisfies the need for a detailed account of trimerophytes. Finally, I am not convinced the subject. that a book on Devonian floras should Viewing the book as an entity, it seems include a detailed account of selected WITHIN palaeobotany, three areas of to me that the authors couldn't decide Lower Carboniferous seeds. major and exciting evolutionary change whether to make it a monograph (though In this review I have concentrated on the can be distinguished. First, the origin and they indicate that it isn't) or a more general shortcomings of the book, but, all in all, early evolution of life in the Precambrian; work. Much of the book (pp.36-314) con Gensel and Andrews have done well in secondly, the rise of vascular land plants in tains good, readable descriptions in partial compiling such a readable volume. Lib the Upper Silurian and Devonian; and monographic form of selected species, to raries will doubtless be the main market, thirdly the origin and evolution of the gether with discussions of heterospory and though palaeobotanists and taxonomists angiosperms in the Lower Cretaceous. early seeds, and more general comments. will be pleased to own a personal copy. For In 1921 E.A. Newell Arber wrote a small An early chapter reviews pre-Devonian the next edition the authors might consider book on Devonian floras. Arber's work plants, particularly the microfloral evi including more information on palaeoecol supported the growing concept that dence from the Upper Ordovician and ogy, floras and evolutionary trends, which Devonian land plants included the most Silurian, and later chapters briefly discuss would broaden the potential readership to primitive of vascular plants, and that this palynology and Devonian floras. include third-year undergraduates. D system was one of great evolutionary In a volume which is assembled from change, thereby encouraging an increasing sifting through an enormous number of Keith Allen is Senior Lecturer in Botany at the number of research workers to study the papers there is bound to be some lack of University of Bristol.