Green Life Through Time

EVOLUTION

Green Life Through Time Jonathan P. Wilson

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ne may be forgiven for thinking that the field of paleobotany, with its focus on nonmotile, largely extinct organisms, should never be described as “fast-moving” except with tongue firmly in cheek. However, the molecular phylogenetics revolution, new fossil discoveries, and reinterpretations of existing mate- Preserved since the Permian. Stomatal complexes in the rial have catapulted our understand- cuticle of the seed fern Dicroidium irnensis (bar = 50 µm). ing of plant evolution ahead, leaving behind hypotheses and interpretations climate and patterns of major adaptive radiathat were as good as fact a mere ten years ago. tions, such as the explosive diversifications of Thankfully, Paleobotany: The Biology and polypodiaceous ferns in tandem with angioEvolution of Fossil Plants captures the current sperm trees during the Late Cretaceous and state of fossil plant anatomy and morphol- Early Paleogene. Taylor, Taylor, and Krings ogy. For this second edition, Michael Krings split the difference by beginning with the (Ludwig Maximilians University, Munich) enigmatic fossils of the Archean Eon and prohas joined the earlier work’s authorial duo of ceeding along each lineage from its appearThomas and Edith Taylor (University of Kan- ance: fungi, nonvascular plants, lycopods, sas). With the field’s major texts long out of ferns, seed plants, and angiosperms. The print and commanding three (or even four) encyclopedic coverage is weighted toward figures online, and molecular, developmental, the last five groups. The authors describe in and paleontological studies locked in various detail vegetative and reproductive structures, stalemates (1–4), this up-to-date, encyclope- where known; summarize variation; and offer dic treatment of fossil plants is a splendid gift comparisons. They give orphaned organ taxa for anyone interested in the evolution of ter- (particularly foliage and seeds) individual restrial life. chapters, in which they note tentative or specAny book that includes two ulative associations with other major thematic axes—increasfossil groups. Paleobotany ing evolutionary diversity and The authors synthesize the The Biology and Evolution complexity on one hand, and recent discoveries that have of Fossil Plants. 2nd ed. time on the other—faces a formade paleobotany crucial to the by Thomas N. Taylor, Edith L. midable organizational chalunderstanding of plant relationTaylor, and Michael Krings lenge. Many environmental ships and diversity. The most Academic (Elsevier), events simultaneously affect welcome additions come from Burlington, MA, 2009. disparate taxonomic groups, descriptions of early angio1252 pp. $125, £62.99, €91.95. whereas evolutionary innovasperm fossils (5, 6), Mesozoic ISBN 9780123739728. tions may lead to within-group seed ferns that almost certainly specializations that deserve to (albeit cryptically) represent the be discussed separately. Simply treating events lineage that led to the origin of flowering plants stratigraphically risks giving short shrift to (7), and Paleozoic plants that demonstrate evolutionary trends, such as the increasingly novel variations on reproductive and vegetarococo reproductive structures of the arbo- tive biology absent in living plants (8). Orgarescent lycopods through the Carboniferous. nisms that the previous edition limited to a few However, a temporal framework makes it eas- pages now occupy complete chapters. Furtherier to portray the effects of large changes in more, the demise of the anthophyte hypothesis (which linked angiosperms to the living seed plants Gnetum, Ephedra, and Welwitschia) has The reviewer is at the Division of Geological and Planetary left a vacuum that could be crippling to a book Sciences, California Institute of Technology, 1200 East focused on the evolution of plants. However, California Boulevard, Pasadena, CA 91125, USA. E-mail: the authors took this development as an [email protected]

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tunity to recapitulate many of the hypotheses that have circulated in the literature over the past hundred years (some fanciful, others quite interesting) along with the available evidence for and against each. By opening the door to a diversity of ideas, the authors turned what could have been a gaping void into an agenda for many a lab meeting or conference session. On opening the cover, two features jump out. The pages are dominated by large color photographs—a first for any textbook on the evolution of plants. And, to preserve the field’s roots, many of these images are photographs (both candid and posed) or paintings of paleobotanical researchers, going back to the early 19th century. (It appears that paleobotanical ideas and facial topiary evolved in parallel.) The color photographs are important because they present morphological details that are crucial to the use of plant fossils in stratigraphy, systematics, and—especially—understanding physiology and function. For example, a comparison of the fascinating wood anatomy of the arborescent lycopods, the Paleozoic sphenophyte Sphenophyllum, and the early fern Zygopteris illinoiensis yields a powerful illustration of the effects of convergent evolution on plant form. For anyone interested in the development, evolution, or impact of plants, this volume deserves to be within arm’s length. It reveals the fossil record of terrestrial plants from the humblest fungal hyphae to the loftiest rainforest trees. Nevertheless, readers, especially those unfamiliar with botany or geology, may find the book daunting. The authors have smoothed the road with chapters on plant morphology, anatomy, and preservation and a useful glossary of terms. The vast amount of anatomical and descriptive detail, however, is staggering. The relative scarcity of cladograms throughout the text may disappoint those having an eye toward the evolutionary relationships of fossil plants. I would urge a closer look: numerous species of virtually every fossil plant genus are fully described and, in most cases, illustrated. A more beneficial and durable data set would be difficult to imagine. Taylor, Taylor, and Krings provide the most accurate, useful, and well-illustrated comprehensive account of fossil plants now in print. Their new edition has caught up with recent discoveries and the progress of thoughts about plant evolution. It points the way toward the most promising avenues for future research. References

1. M. W. Frohlich, M. W. Chase, Nature 450, 1184 (2007). 2. E. M. Friis, K. R. Pedersen, P. R. Crane, Am. J. Bot. 96, 252 (2009). 3. S. Mathews, Am. J. Bot. 96, 228 (2009).

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CREDIT: HANS KERP/WESTFÄLISCHE WILHELMS-UNIVERSITÄT MÜNSTER

BOOKS ET AL.

BOOKS ET AL. 4. G. W. Rothwell, W. L. Crepet, R. A. Stockey, Am. J. Bot. 96, 296 (2009). 5. E. M. Friis, J. A. Doyle, P. K. Endress, Q. Leng, Trends Plant Sci. 8, 369 (2003). 6. G. Sun et al., Science 296, 899 (2002). 7. E. L. Taylor, T. N. Taylor, H. Kerp, E. I. Hermsen, J. Torrey Bot. Soc. 133, 62 (2006). 8. W. E. Stein, F. Mannolini, L. V. Hernick, E. Landing, C. M. Berry, Nature 446, 904 (2007). 10.1126/science.1174659

EXHIBITIONS: ART

An Unsung Refrain of Science Harriet Coles

CREDIT: SICHOV/SIPA/ASSOCIATED PRESS

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lifelike model of an art collector floats face down, dead in a pool while his naked lover (a live model) lounges indoors listening to music. Elsewhere, an artist swings a mallet at huge giltframed mirrors, sending shards of glass flying. These elaborate installations (Michael Elmgreen and Ingar Dragset’s The Collectors and Michelangelo Pistoletto’s Twenty-Two Less Two, respectively) on show at this year’s Venice Biennale either parody or epitomize contemporary art as an exercise in navelgazing—it’s your choice. Amid the buzz of the art world, however, there is another theme: the clear if unsung refrain of the influence of science and technology on contemporary art. It is there in the use of scientific imagery, methods, and technology and in an engagement with cutting-edge science. Since its inception in 1895, Venice’s Biennale has emerged as the world’s biggest and most celebrated art fair. And the 2009 exhibition is the largest yet. Seventy-seven countries show works by their chosen representatives, there are 44 “collateral events” around the city, and there is much more. Venice and its islands are laden with thousands of pieces on display until mid-November. Anatomical images abound. These no longer represent the Renaissance struggle to define and celebrate humanist values but are employed to shock or to explore the darker side of being human. Bruce Nauman’s exhibit in the U.S. Pavilion (winner of the Golden Lion for the best national participation) has a discrete measure of flayed body parts. Jan Fabre, however, is less restrained in his From the Feet to the Brain, which includes corpses, bottled brain, flayed The reviewer is a freelance science writer in London. E-mail: [email protected]

heads, and a resin fountain of ejaculate. Fewer artists set out to explicitly explore The exception to the rule is Bill Viola’s scientific themes. Portugal’s representatives masterly use of contemporary clinical imag- do so in their show named after Joseph Priesting for aesthetic ends. His video diptych Bod- ley’s Experiments and Observations on Differies of Light gently scans an Adam and Eve ent Kinds of Air—a brave venture worth viewpair of figures. Over 21 minutes, a light inter- ing if only to see how science is seen from the mittently sweeps them; four cycles reveal outside. Historic preservationist Jorge Oterothem naked, then their vasculature, their mus- Pailos brings experimental method to his Ethculature, and finally their bones. Here, state- ics of Dust, which shares its title with a pecuof-the-art medical scanning is employed for liar series of lectures John Ruskin published art’s sake. Whereas a doctor in 1865. Otero-Pailos has would employ the technolconserved pollution from Fare Mondi / Making Worlds ogy for clinical enlightena wall at the Doge’s Palace 53rd International Art Exhibition ment, Viola uses it to dimly on a huge latex sheet. The visualize the “tree of vesdust alone creates a specDaniel Birnbaum, Director sels” (da Vinci’s descriptacular sight and becomes Venice Biennale, the Giardini, the tion of vasculature). The a valued cultural product Arsenale, and various other venues, darkened figures are mesin its own right. Venice, Italy. To 22 November 2009. merizing and bring an aesMy favorite among sevwww.labiennale.org/en/art/ thetic to images we take for eral works that play with granted in a scientific conthe psychology of perceptext. Bodies of Light is on show at In-finitum, tion was the Lithuanian Pavilion housed in a superb exhibition at the equally wonderful the Scuola Grande della Misericordia, where Palazzo Fortuny. Žilvinas Kempinas uses video tape to create a Numerous artists use other scientific imag- 20-or-so-meter-long louvered tunnel. Visitors ery either consciously or unwittingly. One of can walk through Tube to great effect: their the most striking results is by Argentinian movements are revealed to them by the apparTomas Saraceno. He explores how complex ent motion of the tunnel walls. It is a threegeometry enables black widow spiders’ silk dimensional extension of Bridget Riley’s Op to suspend considerable weight. Two huge Art of the 1960s. polyhedra of elastic rope are anchored to the The 2009 Venice Biennale offers rich walls, floor, and ceiling of a large room. But pickings and much entertainment. Although would this engineered piece be most at home many of these works are one-trick ponies, all in a science museum, with the art of the piece are part of a great spectacle. 10.1126/science.1177564 taking a back seat?

At the International Pavilion. Saraceno’s Galaxies Forming Along Filaments, Like Droplets Along the Strands of a Spider’s Web.

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