The history of zoology before Charles Darwin's 1859 theory of evolution traces the organized study of the animal kingdom from ancient to modern times. Although the concept of zoology as a single coherent field arose much later, systematic study of zoology is seen in the works of Aristotle and Galen in the ancient Greco-Roman world. This work was developed in the Middle Ages by Islamic medicine and scholarship, and their work was in turn extended by European scholars such as Albertus Magnus.
During the European Renaissance and early modern period, zoological thought was revolutionized in Europe by a renewed interest in empiricism and the discovery of many novel organisms. Prominent in this movement were the anatomist Vesalius and the physiologist William Harvey, who used experimentation and careful observation, and naturalists such as Carl Linnaeus and Buffon who began to classify the diversity of life and the fossil record, as well as the development and behavior of organisms. Microscopy revealed the previously unknown world of microorganisms, paving the way for cell theory. The growing importance of natural theology, partly a response to the rise of mechanical philosophy, encouraged the growth of natural history (although it entrenched the argument from design).
Over the 18th and 19th centuries, zoology became an increasingly professional scientific discipline. Explorer-naturalists such as Alexander von Humboldt investigated the interaction between organisms and their environment, and the ways this relationship depends on geography—laying the foundations for biogeography, ecology and ethology. Naturalists began to reject essentialism and consider the importance of extinction and the mutability of species. Cell theory provided a new perspective on the fundamental basis of life. These developments, as well as the results from embryology and paleontology, were synthesized in Charles Darwin's theory of evolution by natural selection. In 1859, Darwin placed the theory of organic evolution on new footing through his discovery of a process by which it could occur, and observational evidence suggesting that it had done so.
Pre-scientific zoology
The earliest humans must have gathered and transmitted knowledge about animals to increase their chances of survival. This may have included unsystematic knowledge of human and animal anatomy and aspects of animal behavior (such as migration patterns). With the Neolithic Revolution (about 10,000 years ago), humans domesticated animals, and in civilizations such as those of ancient Egypt, pastoralism and farming emerged as alternatives to the hunter-gatherer lifestyle. Magner, A History of the Life Sciences, pp 2–3
Ancient eastern cultures The ancient cultures of Mesopotamia, the Indian subcontinent, and China, among others, produced renowned surgeons and students of the natural sciences such as Susruta and Zhang Zhongjing, reflecting sophisticated and independent systems of natural philosophy. Taoist philosophers, such as Zhuangzi in the 4th century BC, expressed ideas related to evolution, such as denying the fixity of biological species and speculating that species had developed differing attributes in response to differing environments. The ancient Indian Ayurveda tradition developed a theory of three humors, resembling but unrelated to the four humors of ancient Greek medicine (and including further complications, such as the body being composed of five elements and seven basic tissues). Ayurvedic writers also classified living things into four categories based on the way they were born (from the womb, from eggs, from seeds, or via heat and moisture) and explained the conception of a fetus in detail. They also made considerable advances in the field of surgery, often without the use of human dissection or animal vivisection.Magner, A History of the Life Sciences, p. 6 One of the first known Ayurvedic treatises was the Sushruta Samhita, attributed to Sushruta in the 6th century BC. It can be considered an early contribution to the materia medica genre, describing 700 medicinal plants, 64 preparations from mineral sources, and 57 preparations based on animal sources. Notwithstanding such developments, the roots of modern zoology are usually traced back to the secular tradition of ancient Greek philosophy.Magner, A History of the Life Sciences, pp 3–9
Ancient Greek traditions
The pre-Socratic philosophers asked many questions about life but produced little systematic knowledge of specifically zoological interest—though the attempts of the atomists to explain life in purely physical terms would recur periodically through the history of zoology. However, the medical theories of Hippocrates and his followers, especially humorism, had a lasting impact.Magner, A History of the Life Sciences, pp 9–27
Aristotelian zoology Aristotle
The philosopher Aristotle created the science of biology, basing its theory on both his metaphysical principles and on observation. He proposed theories for the processes of metabolism, temperature regulation, information processing, embryonic development, and inheritance. He made detailed observations of nature, especially the habits and attributes of animals in the sea at Lesbos. He classified 540 animal species, and dissected at least 50.Mayr, The Growth of Biological Thought, pp 84–90, 135Mason, A History of the Sciences, pp 41–44
Aristotle, and nearly all Western scholars after him until the 18th century, believed that creatures were arranged in a graded scale of perfection rising from plants on up to humans: the scala naturae or Great Chain of Being.Mayr, The Growth of Biological Thought, pp 201–202; see also: Lovejoy, The Great Chain of Being
Hellenistic zoology
A few scholars in the Hellenistic period under the Ptolemies—particularly Herophilus of Chalcedon and Erasistratus of Chios—amended Aristotle's physiological work, even performing experimental dissections and vivisections.Barnes, Hellenistic Philosophy and Science, p 383–384 Claudius Galen became the most important authority on medicine and anatomy. Though a few ancient atomists such as Lucretius challenged the teleological Aristotelian viewpoint that all aspects of life are the result of design or purpose, teleology (and after the rise of Christianity, natural theology) remained central to biological thought until the 18th and 19th centuries.Annas, Classical Greek Philosophy, p 252
Medieval and Islamic zoology
The decline of the Roman Empire led to the disappearance or destruction of much knowledge, though physicians still incorporated many aspects of the Aristotelian tradition into training and practice. In Byzantium and the Islamic world, many of Aristotle's works were translated into Arabic and commented upon by scholars such as Avicenna and Averroes.Mayr, The Growth of Biological Thought, pp 91–94
Medieval Muslim physicians, scientists and philosophers made significant contributions to zoological knowledge between the 8th and 13th centuries during the Islamic Golden Age. The Arab scholar al-Jahiz (781–869) described the idea of a food chain,Frank N. Egerton, "A History of the Ecological Sciences, Part 6: Arabic Language Science - Origins and Zoological", Bulletin of the Ecological Society of America, April 2002: 142–146 and was an early adherent of environmental determinism.Lawrence I. Conrad (1982), "Taun and Waba: Conceptions of Plague and Pestilence in Early Islam", Journal of the Economic and Social History of the Orient 25 (3), pp. 268–307 .
During the High Middle Ages, a few European scholars such as Hildegard of Bingen, Albertus Magnus and Frederick II expanded the natural history canon. Magnus's De animalibus libri XXVI was one of the most extensive studies of zoological observation published before modern times.Albertus Magnus. On Animals: A Medieval Summa Zoologica. The Review of Metaphysics | December 01, 2001 | Tkacz, Michael W.Mayr, The Growth of Biological Thought, pp 91–94: "As far as biology as a whole is concerned, it was not until the late eighteenth and early nineteenth century that the universities became centers of biological research."
Renaissance and early modern
From anatomy to systematic taxonomy
The Renaissance was the age of collectors and travellers, when many of the stories were actually demonstrated as true when the living or preserved specimens were brought to Europe. Verification by collecting of things, instead of the accumulation of anecdotes, then became more common, and scholars developed a new faculty of careful observation. See especially pp. 1022–1024. The Renaissance brought expanded interest in both empirical natural history and physiology. In 1543, Andreas Vesalius inaugurated the modern era of Western medicine with his seminal human anatomy treatise De humani corporis fabrica, which was based on dissection of corpses. Vesalius was the first in a series of anatomists who gradually replaced scholasticism with empiricism in physiology and medicine, relying on first-hand experience rather than authority and abstract reasoning. Bestiaries—a genre that combines both the natural and figurative knowledge of animals—also became more sophisticated. Conrad Gessner's great zoological work, Historiae animalium, appeared in four volumes, 1551–1558, at Zürich, a fifth being issued in 1587. His works were the starting-point of modern zoology. Other major works were produced by William Turner, Pierre Belon, Guillaume Rondelet, and Ulisse Aldrovandi.Mayr, The Growth of Biological Thought, pp 166–171 Artists such as Albrecht Dürer and Leonardo da Vinci, often working with naturalists, were also interested in the bodies of animals and humans, studying physiology in detail and contributing to the growth of anatomical knowledge.Magner, A History of the Life Sciences, pp 80–83
In the 17th century, the enthusiasts of the new sciences, the investigators of nature by means of observation and experiment, banded themselves into academies or societies for mutual support and discourse. The first founded of surviving European academies, the Academia Naturae Curiosorum (1651) especially confined itself to the description and illustration of the structure of plants and animals; eleven years later (1662) the Royal Society of London was incorporated by royal charter, having existed without a name or fixed organisation for seventeen years previously (from 1645). A little later the Academy of Sciences of Paris was established by Louis XIV, later still the Royal Society of Sciences in Uppsala was founded. Systematizing, naming and classifying dominated zoology throughout the 17th and 18th centuries. Carl Linnaeus published a basic taxonomy for the natural world in 1735 (variations of which have been in use ever since), and in the 1750s introduced scientific names for all his species.Mayr, The Growth of Biological Thought, chapter 4 While Linnaeus conceived of species as unchanging parts of a designed hierarchy, the other great naturalist of the 18th century, Georges-Louis Leclerc, Comte de Buffon, treated species as artificial categories and living forms as malleable—even suggesting the possibility of common descent. Though he was writing in an era before evolution was recognized, Buffon is a key figure in the history of evolutionary thought; his "transformist" theory would influence the evolutionary theories of both Jean-Baptiste Lamarck and Charles Darwin.Mayr, The Growth of Biological Thought, chapter 7
Before the Age of Exploration, naturalists had little idea of the sheer scale of biological diversity. The discovery and description of new species and the collection of specimens became a passion of scientific gentlemen and a lucrative enterprise for entrepreneurs; many naturalists traveled the globe in search of scientific knowledge and adventure.See Raby, Bright Paradise