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American Zoologists

  1. AMERICAN HOLIDAYS
  2. Changes in response to experience. Scientific American, 226,22-29.
  3. Gibson E. J., & Walk R. D. (1960). The «visual cliff». Scientific American, 202, 67-71.
  4. Outcome studies. American Psychologist, 32, 752-760.
  5. The American Political System
  6. The phonetic system of American variants of the English language.

Thomas Say (1787-1834), sometimes called "the father of American entomology," and Joseph Leidy (1823-1891), probably the first American paleozoologist, were early outstanding zoologists in the United States. Other wellknown zoologists include Joel Asaph Allen (1838-1921), a specialist in mammals and birds, and one of the founders of the Audubon Society; Thomas Barbour (1884-1946), the herpetologist and ornithologist who developed zoological research at the first American tropical-research stations in Cuba and Panama; and Alexander Wetmore (1886-1978), who specialized in the study of birds from Central and South America and the Caribbean.

Other American zoologists contributed greatly to knowledge of extinct forms of life. Othniel Charles Marsh (1831-1899), whose reconstruction of the evolution of horses became the standard illustration in biological textbooks during the twentieth century, and Edward Drinker Cope (1840-1897), author of a peculiar version of the evolutionary theory, were competitors in the search for dinosaur fossils. Between them they discovered and described more than 100 new species of dinosaurs. Henry Fairfield Osborn (1857-1935) reconstructed the phylogeny of elephants among many contributions to paleozoology. A specialist in fossil mammals, William Diller Matthew (1871-1930) wrote Climate and Evolution (1915), arguing against explaining animal distribution only in terms of connections between land masses. Although many ideas put forward by these researchers have been revised or even rejected, their work contributed significantly to the general advancement of zoology and paleontology.

Some zoologists wrote very influential books: Philip Jackson Darlington (1904-1983), an entomologist, published a widely read Zoogeography (1957); and Libbie Henrietta Hyman (1888-1969) published a six-volume monograph, The Invertebrates (1940-1967), that remains the standard reference work. The best known American women zoologists are, undoubtedly, Rachel Louise Carson (1907-1964), the author of one of the most influential books published during the twentieth century, Silent Spring (1962); and Dian Fossey (1932-1985), who wrote Gorillas in the Mist (1983), about her experiences studying gorillas in Central Africa.

Zoologist and geneticist Theodosius Dobzhansky (1900-1975); ornithologist Ernst Mayr (1904-) and mammalogist and paleozoologist George Gaylord Simpson (1902-1984) are among the developers of the contemporary version of Darwin's evolutionary theory, known as the "synthetic theory of evolution" (it "synthesizes" systematics, Genetics, ecology, and paleontology). Their three great books Genetics and the Origin of Species (1937), Systematics and the Origin of Species (1942), and Tempo and Mode in Evolution (1944), respectively, have become classics of twentieth-century biological literature. Simpson's The Meaning of Evolution (1949), a popular presentation of the synthetic theory, was widely read in the United States and translated into several languages.

Perhaps the best known contemporary American zoologists are Stephen Jay Gould (1941-2002), a paleozoologist, author of many books and articles on the history of zoology, and one of the creators of the evolutionary theory of "punctuated equilibrium," and Edward Osborne Wilson (b. 1929), an ant specialist and an active promoter of conservationist policies and attitudes, as well as the author of Sociobiology: The New Synthesis (1975).

From earliest times animals have been vitally important to man; cave art demonstrates the practical and mystical significance animals held for prehistoric man. Early efforts to classify animals were based on physical resemblance, habitat, or economic use. Although Hippocrates and Aristotle did much toward organizing the scientific thought of their times, systematic investigation declined under the Romans and, after Galen's notable contributions, came to a virtual halt lasting through the Middle Ages (except among the Arab physicians). With the Renaissance direct observation of nature revived; landmarks were Vesalius' anatomy and Harvey's demonstration of the circulation of blood. The invention of the microscope and the use of experimental techniques expanded zoology as a field and established many of its branches, e.g., cytology and histology. Studies in embryology and morphology revealed much about the nature of growth and the biological relationships of animals. The system of binomial nomenclature (see classification) was devised to indicate these relationships; Linnaeus was the first to make it consistent and apply it systematically. Paleontology, the study of fossil organisms, was founded as a science by Cuvier c.1812. Knowledge of physiological processes expanded greatly when physiology was integrated with the chemical and other physical sciences. The establishment of the cell theory in 1839 and the acceptance of protoplasm as the stuff of life 30 years later gave impetus to the development of genetics. Lamarck, Mendel, and Darwin presented concepts that revolutionized scientific thought. Their theories of evolution and of the physical basis of heredity prompted research into all life processes and into the relationships of all organisms. The classic work of Pasteur and Koch opened up bacteriology as a field. Modern zoology has not only concentrated on the cell, its parts and functions, and on expanding the knowledge of cytology, physiology, and biochemistry, but it has also explored such areas as psychology, anthropology, and ecology.

For much of the sixteenth century, as in earlier periods, animals were valued for use or for their symbolic or allegorical meaning. Medieval bestiaries, based on the Natural History of Pliny and the encyclopedic works of such early church fathers as Isidore of Seville, mingled naturalistic description, uses, and symbolic significance in their accounts of animals, and did not clearly demarcate real from mythological beasts. Conrad Gessner's Historia Animalium (Description of animals) of 1551, the era's most comprehensive text on animals, continued this mode of description, still evident fifty years later in Edward Topsell's revised translation, A History of Four-Footed Beastes (1607). Animals were classified in hierarchical terms centered on the notion of the great chain of being. However, the voyages of discovery and the intellectual changes associated with the scientific revolution began to strip away the layers of symbol and allegory from animals and made them objects of study in themselves.

Animals had been used as surrogates for humans in the training of physicians and surgeons since the twelfth century. Even after human dissection began to be practiced in the fourteenth century, medical schools continued to use animals, especially pigs, dogs, and cats, to teach human anatomy by means of both dissection and vivisection. The beginnings of comparative anatomy are usually dated to the appearance in 1551 of Pierre Belon's (1517-1564) work on the anatomy of cetaceans, soon followed by his comparison of a human skeleton to that of a bird (1555). Volker Coiter (1534-1576) established comparative anatomy as an autonomous field of study in the 1570s, and while animals continued to function as human proxies, numerous works appeared on animal anatomy and physiology as well.

Exotic animals were a form of diplomatic exchange dating back to Roman times. Medieval monarchs established menageries such as that at the Tower of London, which during the sixteenth century included lions, leopards, a tiger, a lynx, an eagle, and a porcupine. Animals in menageries were often used for sport in the form of animal combats or baiting. Louis XIV of France established a menagerie at his palace at Versailles; when the animals died, they were dissected before the Paris Academy of Sciences, and many of them were described in Claude Perrault's (1613-1688) Mémoires pour servir à l'histoire naturelle des animaux (1671-1676; Memoirs for a natural history of animals). After death, these animals graced natural history cabinets (among which Gessner's was famous), which also included plants, antiquities, minerals, and curiosities. These predecessors of the modern natural history museum attempted to make sense of a rapidly expanding world by means of analogies, etymologies, and seemingly odd juxtapositions and also served important social and cultural roles in an aristocratic society based on status and patronage.

The work of Perrault's team and others such as Edward Tyson (1651-1708) made great strides in comparative anatomy. However, the main use of animals in science from the end of the sixteenth century onward was to demonstrate aspects of human (and animal) anatomy and physiology, for instruction and especially for research. William Harvey (1578-1657) demonstrated the circulation of the blood, published in 1628, by means of hundreds of experiments on live animals ranging from fish to dogs. Experimenters in universities and academies all over Europe embraced Harvey's experimental techniques, which included injection and inflation as well as vivisection. Notable examples included the work of Marcello Malpighi (1628-1694) on the structure of the lungs and the capillary circulation, Robert Hooke (1635-1704) on the process of respiration, Regnier de Graaf (1641-1673) on the glands, and Nicolaus Steno (1638-1686) on the structure of the muscles. Hooke and Robert Boyle (1627-1691) placed small animals in a vacuum pump of their design and demonstrated the body's need for fresh air to sustain life. Antoni van Leeuwenhoek (1632-1723) revealed the possibilities of the microscope, also used successfully by Malpighi and Hooke.

Most seventeenth-century natural philosophers regarded animals as machines, although few went as far as René Descartes (1596-1650) in denying their mental capacity to experience pain. Vitalist philosophies revived in the eighteenth century, although the mechanical philosophy continued to influence views of animal function. The work of Stephen Hales (1671-1767) on blood pressure was mechanistic, but by mid-century, Albrecht von Haller (1708-1777) exemplified the new emphasis on vital function with his work on the sensibility and irritability of the nerves. At the beginning of his 1752 treatise on this topic, Haller also displayed a new sensibility toward animals when he apologized for causing them pain.

By the end of the seventeenth century, concepts of classification had reached a crisis. The seemingly chaotic organization of cabinets and collections reflected a lack of consensus on classification schemes. The great influx of animals from the New World and other areas disrupted the old notion of a chain of being that was both full and complete, but there was little agreement about what might be a proper criterion for classification. Although Aristotle had attempted to establish a natural system of classification based on essential features and natural affinities, he also believed in a natural hierarchy. Various theories of plant classification multiplied, but the classification of animals lagged behind. At the end of the seventeenth century, John Ray (1627-1705) attempted a natural classification of animals, but its complexity did not bode well for future endeavors. In 1735, Carl Linnaeus (1707-1778) described a classification of plants based on sexual parts in his Systema Naturae (System of nature), which also presented a scheme for classifying animals, organizing them in six broad classes. In the 1779 edition of Systema Naturae, he described nearly six thousand species of animals. His system was artificial, aimed at establishing order rather than reproducing nature's plan, and its use of the binomial nomenclature was widely adopted.

Linnaeus's system of classification was challenged by Georges-Louis Leclerc, comte de Buffon (1707-1788), whose Histoire naturelle (1749-1788; Natural history) was the most comprehensive (and best-known) work on natural history in the eighteenth century. Buffon argued that any system of classification was by definition arbitrary and artificial, and that reality resided in individuals, not in species. While he modified his views over the course of his life, adopting many Linnaean categories, Buffon is especially important for introducing the concept of time into the discussion of taxonomy, finding variability of species over time but constancy of form at higher taxonomic levels.

By the end of the eighteenth century, animals had lost much of their earlier symbolic meaning. But in both laboratories and natural history museums they were, more than ever, objects of scientific scrutiny.

 



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