Tag Archives: botany

The Press Reads: Trees of Life

Our occasional Friday series on the blog, The Press Reads, features short excerpts from recent JHUP books. We hope to whet your appetite and inspire additions to your reading list.  Today’s selection is drawn from the preface of Trees of Life: A Visual History of Evolution by Theodore W. Pietsch. Trees of Life, embraced by reviewers across many disciplines, is now available in trade paperback.

 

Ernst Haeckel's family tree of the mammals, from 1866.

Ernst Haeckel’s family tree of the mammals, from 1866.

This is a book about  trees—not the transpiring, photosynthesizing kind, but tree-like branching diagrams that attempt to show the interrelationships of organisms, from viruses and bacteria to birds and mammals, both living and fossil. It is not intended as a treatise about the philosophy or science behind tree construction, nor is it a defense or refutation of the various relationships depicted among organisms. It is rather a celebration of the manifest beauty, intrinsic interest, and human ingenuity revealed in trees of life through time.

A phylogeny of elephants constructed by Henry Fairfield Osborn in 1926, this one a "pictogram," showing relationships, but also an indication of relative size, and the remarkable convergence of general body shape among modern forms descended from markedly different ancestors.

A phylogeny of elephants constructed by Henry Fairfield Osborn in 1926, this one a “pictogram,” showing relationships, but also an indication of relative size, and the remarkable convergence of general body shape among modern forms descended from markedly different ancestors.

The emphasis is on the images, arranged chronologically, two hundred and thirty chosen from among thousands of possibilities, dating from the mid-sixteenth century to the present day. The descriptive text is kept to a  minimum—just enough to provide context.

The frontispiece of William King Gregory's two-volume Evolution Emerging.

The frontispiece of William King Gregory’s two-volume Evolution Emerging.

The focus of this book is on diagrams that resemble trees in the botanical sense, images with parts analogous to trunks, limbs, and terminal twigs, but other configurations are also explored as precursors and variations on the theme of biosystematic iconography. These various related images include bracketed  tables—trees laid on their  side—similar to modern-day analytical keys; maps, or so-called archipelagos, that hypothesize relationships analogous to the juxtaposition of geographical territories; webs or networks, in which individual taxa or chains of taxa are interconnected by lines of affinity or resemblance; and various numerical, symmetrical and geometric systems.

Dinosaur tree by Paul Callistus Sereno, emphasizing the sharp dichotomy between the two orders, the Ornithischia on the left and the Saurischia on the right.

Dinosaur tree by Paul Callistus Sereno, emphasizing the sharp dichotomy between the two orders, the Ornithischia on the left and the Saurischia on the right.

While their choice of imagery varied considerably, most all eighteenth- and early nineteenth-century naturalists were working toward the same goal: to construct classifications of plants and animals that were “natural.” Their thought was that organisms brought together in “natural classifications” ought to share “natural affinities.” But just exactly what was meant by “natural affinity,” remained an unresolved question. It was Darwin’s theory of evolutionary change by means of natural selection that provided the missing context and unified the work of biosystematists in their pursuit of a natural system of classification. The phylogenetic tree as we know it today was one conspicuous result.

A universal tree of life based on ribosomal RNA sequences, sampled from about 3,000 species from throughout biodiversity, and constructed by David Mark Hillis and colleagues at the University of Texas at Austin.

A universal tree of life based on ribosomal RNA sequences, sampled from about 3,000 species from throughout biodiversity, and constructed by David Mark Hillis and colleagues at the University of Texas at Austin.


Brain Pickings posted a review of Trees of Life, which you can read here.

“A luminous book . . . For classroom use, the brevity and simplicity of the introductory remarks will serve instructors who wish to teach these images’ and their authors’ significance to the history of biology and the history of scientific illustration. Biologists, historians of science, scholars interested in the intersections between art and design and science will find an abundance of images and wise commentary that reveals new details with each reading.”

— Christine Manganaro, Journal of the History of Biology

“With the concept of evolution now often iconified to the point of misrepresentation, Trees of Life reminds us that both the idea and its representation were—and are—fluid, debated, and reconstructed.”

—Camillia Matuk, Science

“Trees of Life commemorates the tree as a visual representation of life; science buffs will revel in this dazzling forest of transformation.”

—Jen Forbus, Shelf Awareness

pietsch_JACKET COMP5.inddTheodore W. Pietsch is Dorothy T. Gilbert Professor in the School of Aquatic and Fishery Sciences and Curator of Fishes at the Burke Museum of Natural History and Culture at the University of Washington in Seattle. He is the author of more than a dozen books, including The Curious Death of Peter Artedi: A Mystery in the History of Science and Oceanic Anglerfishes: Extraordinary Diversity in the Deep Sea.

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Filed under Animals, Botany, Conservation, Evolution

Spring smells of lilacs

 Guest Post by Holly DuganLilac drawing

Early spring is, famously, cruel. The bite of winter is still sharp, even “whan that Aprille with his shoures soote / the droghte of Marche hath perced to the roote” (“when that April with his sweet showers pierce the drought of March”). Chaucer’s famous opening lines of the Canterbury Tales emphasize the sensory contradictions of this time of year, especially its flowers. Spring is a botanical paradox, one as poetic as it is perfumed. It is a season of renewal and rebirth. And for many, including T.S. Eliot, it smells of lilacs.

Eliot’s “Wasteland” begins by echoing Chaucer’s opening lines, defining the “cruelty” of April through its “breeding” of lilacs “out of the dead land / mixing memory and desire / stirring dull roots with spring rain.” Eliot’s poem expertly crafts an elegy for the modern age out of poetry from the past, yet in doing so, it also (perhaps unintentionally) emphasizes a historical anomaly: there were no lilacs in medieval England. Chaucer may have been describing the scent of spring, but he was not describing lilacs. Yet, for Eliot, the two are entwined.

A flower that depends upon a heavy frost in order to bloom, lilacs thrive in eastern North American and central European climates. One of the first flowers of spring, and heavy with indole (an aromatic compound found in both flowers and feces), lilacs can smell fresh at first and then, quickly thereafter, decayed and rotten. Both Walt Whitman and Eliot use this to great effect in their poetry, tempering the promise of spring with an indolic hint of decay and desolation. In Whitman’s famous elegy for Lincoln, the poet longs for the promise of an “ever-returning spring,” a time “when lilacs last in the door-yard bloom’d.” With “heart-shaped leaves of rich green,” lilacs “rise delicately” with their “perfume strong,” a smell the poet “loves.” Yet that smell becomes a powerful reminder of mourning: since the lilac “blooms the first,” the poet “breaks, breaks the sprigs from bushes,” and comes “with loaded arms” to pour them on the coffin and to mourn and “perfume the grave of him I love.” Eliot does something similar with the smell of lilacs in his own elegiac riff on Chaucer.

This is the stuff of great poetry, which may seem separate from history, yet all three poems offer a unique way to approach the history of olfaction. How and when did lilacs become associated with the smell of spring? That the “smell of spring” has a history may seem counterintuitive; olfaction, deemed the most fleeting and most subjective of all the senses, is often assumed to have no history. Smell is difficult to describe as well to historicize, and yet it is for this reason that poetry seems a particularly useful archive for capturing its meanings in the past. That the smell of lilacs signals early spring may seem intuitive. When we smell lilacs, we don’t think of the long history of science and trade that made lilacs recognizable to us; we think even less of the history of gardening and the ways it has shaped our homes and our leisure time. More likely we’re rooted in something much closer to us and much more subjective: our own sensory history—personal, powerful, and much more visceral connections to our material world. Yet as Whitman and Eliot’s poems suggest, these visceral connections are entwined with aesthetic traditions that precede us. The smell of lilacs, like other smells, represents a perfect amalgamation of both our shared cultural histories and of our own subjectivity, rooted in our perception of the world around us.

Lilac, as a scent of spring, has a history, one that begins in antiquity in Persian gardens, expands in the Renaissance through the rise of global trade—especially trade of biological matter—and becomes naturalized in Europe during the Enlightenment through gardening, so much so that, by the nineteenth century, it signals a lost connection to the natural world, one rapidly receding with the rise of industrialism. It is a tale of enlightenment breakthroughs in perfumery, including the process of enfleurage, as well as modernist breakthroughs in chemistry, including synthetic aroma-chemicals that approximated its scent and rendered it more readily available as a “note” in commercial perfumes. By the mid-twentieth century, the smell of spring was available all year round, bottled in laundry and dish detergents.

When we smell a lilac, we may reflect on some of these aspects of history, but more likely, we are transported to a different time and place—our garden, the funeral of a friend, or our grandmother’s perfume. This is what scientists now describe as a “Proustian” memory: an involuntary sensory memory that is triggered not only by a molecule the nose is designed to recognize but also by whether or not we’ ve encountered that molecule before. That science turned to literature to describe this process should not surprise anyone who has read Proust, Chaucer, Whitman or Eliot. As the Nobel Assembly of the Karolinska Institute noted when they awarded the 2005 Nobel Prize in physiology to Dr. Richard Axel and Dr. Linda Buck for their groundbreaking research on the science of olfaction, smell is essential to human life, both its survival as well as more ephemeral pleasures, like enjoying fine wine or “appreciating a beautiful lilac” in spring.

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dugan_RGBHolly Dugan is  the author of The Ephemeral History of Perfume: Scent and Sense in Early Modern England, published by Johns Hopkins. She is an assistant professor of English literature at the George Washington University.

 

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Filed under Literature, Poetry