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1.11. The Swedish botanist Karl Linnaeus (1707-78), founder of our modern system of binomial nomenclature. Photo: AMNH Library.

1.12. Opening page of the tenth edition of Linnaeus' Systema Naturae (1758), the starting point of zoological nomenclature. Photo: AMNH Library.

1.13. A plate from Maria Sibylla Merian's Metamorphosis Insectorum Surinamensium (1705). Merian's beautiful and detailed works had a strong influence on Linnaeus' later treatment of insects. Photo: AMNH.

1.14. Johann C. Fabricius (1745-1808), student of Linnaeus and the first specialist on entomology. Photo: Deutsche Entomologische Institut.

use of a hand lens. Fabricius' thinking even predated evolutionism: "die nach und nach in Arten übergehende [sic] festen Abänderungen" (p. 24) ["the stable varieties which little by little change into species," as translated by Tuxen (1967a)]. Justifiably, Fabricius is considered the original insect taxonomist, whose study of insects far eclipsed that of his renowned mentor, and even Linnaeus later on accomodated Fabricius' classification of insects into his own.

Another famous entomologist of this era was Pierre André Latreille (1762-1833) (Figure 1.15), who was even called the "foremost entomologist" by luminaries such as Fabricius (Geoffroy Saint-Hilaire et al., 1833; Dupuis, 1974), with whom he was a regular correspondent. Latreille received a formal education and attended seminary, eventually becoming a priest. However, during the formative years of the French Revolution he failed to take the newly instigated civic oath for priests and was therefore condemned for execution and imprisoned. While in prison, Latreille identified a new species of beetle, Necrobia ruficollis and, with the aid of two fellow naturalists, was able to secure his release as an entomologist (perhaps the only time the discovery of a new species saved someone's life!). Latreille relinquished his priesthood and, through a series of teaching positions, arrived at the Museum National d'Histoire Naturelle in Paris, eventually receiving a professorship there at the age of 68. Although Latreille was quite prolific and produced numerous fine volumes on the classification of arthropods, he is most noted for his Précis des Caractères Génériques des Insectes (Latreille, 1796). In this work he attempted a natural classification of the Arthropoda, delimiting within each order for the first time what we would today call families, although he did not formally name them until subsequent publications.

The pursuit of a natural classification during the late 1700s and early 1800s eventually developed into evolutionary theory, methods of phylogenetic reconstruction, and modern predictive classifications that allow us to explore the diversification of life and evolution of biological phenomena. The debates at the time included questions such as, What could be the origin of such apparent "natural affinities"? and What made groups natural? Ideas varied from patterns in nature reflecting the thoughts of a divine creator, to the other extreme with no pattern, all of which was a figment of human imagination (order imposed on an otherwise chaotic world). Other scholars believed that nature was harmonic and fell into mathematical sets, the most famous being the Quinari-ans whose system set nature into groups of five. Naturalists increasingly found that biological traits (characters) of organisms formed hierarchical groups and that these groups did not correspond to harmonic numbers and were not arbitrary. As Darwin (1859) himself noted: "From the most remote period in the history of the world organic beings have been found to resemble each other in descending degrees, so that they can be classed in groups under groups. This classification is not arbitrary like the grouping of the stars in constellations." Another question also plagued naturalists, What was the origin of species? Where did species come from? The answer was simple: from God. For insects, this is best seen in

1.15. The famous French entomologist, Pierre André Latreille (1762-1833). During the French Revolution, Latreille was scheduled to be executed but was spared after he discovered a new species of beetle in his prison cell. Photo: © Bibliothèque Centrale MNHN Paris 2003.

1.16. A plate from Johann Scheuchzer's Physique Sacrée, ou Histoire Naturelle de la Bible (1732), depicting a divine creation of insects (cf. Figure 1.9). Photo: Carl A. Kroch Library, Cornell University.

1.17. Baron Georges Cuvier (1769-1832), the great French morphol-ogist who was the first to carefully document that fossils were the remains of extinct animals. Photo: AMNH Library.

the volume Physique Sacrée, ou Histoire Naturelle de la Bible of the Swiss naturalist, Johann Jacob Scheuchzer (1672-1733). There Scheuchzer depicted creation for many groups, including terrestrial arthropods, but of course he only gleaned the surface (Figure 1.16).

Numerous luminaries contributed to the debates about classification. Georges L. Leclerc, Comte de Buffon (17071788) published a 44-volume series on natural history. Influenced by Sir Isaac Newton and the concept of physical laws, Buffon worked toward the production of a classification of natural classes, which was based on functional morphology, and he was not interested in the systematic methods of his contemporary Linnaeus. In systematic theory, however, two contemporaries at the newly founded Museum National d'Histoire Naturelle in Paris (formed from the collections of Buffon) were to make the greatest contributions, and their debates set the stage for some of the most critical ideas in evolutionary thinking. Georges L. C. F. D. Cuvier (1769-1832) (Figure 1.17), who was eventually made a Baron, decided that the characters that formed natural groups were adaptive. Cuvier in large part continued the tradition of Buffon and worked toward a classification based on functional laws. He also decided that fossils were truly the remains of extinct organisms, although this troubled him because he believed that all species were created at 9 a.m. on the 26th of October

4004 b.c. (as calculated by the theologian Bishop Ussher: Ussher, 1650). Could God change his mind? The notion of the Biblical Flood, however, could easily account for the loss of such animals, and this idea would be carried forward by numerous scientists including William Buckland, who had a significant influence on the young Charles Darwin. Also in the Museum National d'Histoire Naturelle was Etienne Geoffroy St. Hilaire (1772-1844), a gentleman who did the most to develop the concept of homology (although he employed the antonym "analogy" for what we today call "homology") and Jean Baptiste I? A. M. de Lamarck (1744-1829), who developed an alternative explanation. Lamarck considered that God created a few forms, which then transformed into the various kinds we see. This explanation was certainly a precursor to Darwin's theory of evolution; however, Lamarck failed to develop a plausible mechanism by which such transformations might form.

Geology and Evolution Step In

While the French debated homologies and the Scandinavians devised classifications, the British naturalists and geologists, such as William Smith, were making remarkable discoveries about the Earth and its diversity. Among them, Sir Charles Lyell (1797-1875) (Figure 1.18) produced a major synthesis that led to new concepts of the earth. Lyell, building upon his

1.18. Sir Charles Lyell (1797-1875), whose extensive work on the long, slow accretion of geological forces had a major impact on Darwin's concept of evolutionary time. Photo: AMNH Library.

1.19. The title page of volume one of Lyell's Principles of Geology (1830), the work that revolutionized geological thought. Photo: AMNH Library.

extensive travels and historical accounts from around the world, pieced together geological observations and united them with the discoveries of his predecessors and contemporaries. Lyell united ideas on present-day mechanisms such as the accumulation of sediments and erosion, with geological patterns such as continuity of stratigraphic layers and index fossils. As such, he provided the logic for an ancient earth. The publication in 1830 of Lyell's three-volume Principles of Geology (Figure 1.19), revealed that the earth was ancient, and that massive formations accumulated slowly over time by forces still acting today (called uniformitarianism). As is well known, this work had a great impact on another British scientist whose theory of natural selection revolutionized biology.

Darwin and Wallace

Charles R. Darwin (1809-1882) (Figure 1.20) and Alfred Russel Wallace (1823-1913) (Figure 1.21) were naturalists, the systematists of the day, and they synthesized their knowledge of nature into ideas on the minute, everyday increments that accumulate over geological time to produce the diversity of organisms. They noted that forms of life were interrelated in a seemingly hierarchical fashion, and that if the hierarchy of relationships was spread out over geological time it formed a branching tree. If the earth is as old as Lyell suggested, the continuum of life would be over millions of years (today we understand it to be at least 3.8 billion years old). Darwin noted various slow processes that create variations in organisms, such as animal breeding that produces good, bad, or even exotic traits, and how some variations are better adapted to survive than others. Thus, Darwin revisited the question of his time: What is the origin of species? (Figure 1.22). His answer, which was that species come from ancestral species that changed through time to produce new

1.20. Charles R. Darwin (1809-82), the architect of modern evolutionary thought and, among other things, a talented field naturalist. Photo: AMNH Library.

species, was not particularly original. His explanation for the mechanism of evolutionary change was, however, entirely original: It is the result of natural selection. A natural by-product of Darwin and Wallace's mechanism was that, by acting over great expanses of geological time, evolutionary change via natural selection would produce a hierarchy of life. Without altering the practice of systematics, Darwin and Wallace revolutionized the theory behind it. Pre-evolutionary systematists had extensive evidence that evolution had occurred. Darwin and Wallace extracted patterns from sys-tematics and natural history and simply added the evolutionary interpretation to it. This theory and mechanism could then also explain patterns seen in the fossil record, variations among species around the world, the distribution of related organisms, the similarities seen in embryology, etc. Evolution and the mechanism of natural selection further explained the hierarchical nature of life.

Darwin's influence on classification was strictly theoretical. His work had little effect on the day-to-day practice of systematics: "Systematists will be able to pursue their labours as at present" (Darwin, 1859: p. 405). Indeed, nothing needed

1.21. Alfred R. Wallace (1823-1913), adventurer, naturalist, and prolific insect collector. Wallace was coauthor with Darwin on the original paper proposing evolution by means of natural selection. Photo: AMNH Library.

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