The Development of Zoology

Overview

Zoology, the branch of biology that studies animals, seeks to understand the sum total of all the properties of animals and animal populations. As a discipline, zoology is similar to others with major subdivisions that include anatomy, physiology, genetics, and interrelationships.

Much of the early information about human anatomy came from the dissection and study of animals, although some efforts were made to understand and classify animals. It was during the Renaissance that the study of zoology began to separate from human anatomy, as great artists who sought to understand the makeup of both men and animals emerged. Great natural scientists, such as Konrad Gesner (1516-1565), recognized as the father of zoology, developed the field as a scientific inquiry. Other investigators, such as Guillaume Rondelet (1507-1566) and Ulisse Aldrovandi (1522-1605), contributed accurate observations of animals. Natural philosopher and theologian John Ray (1627-1705) also sought to understand and classify all known animals.

The classification and physiological studies by these early naturalists provided the foundation upon which the zoology of the nineteenth century was unified by the theory of evolution. Comparison of animals allowed an understanding of how various animals might have developed. Zoology in the late twentieth century developed as a major force behind the understanding of total interrelationships and the ecology movement.

Background

Philosophers and thinkers throughout history have looked at animals and attempted to understand them by classifying and relating anatomy and physiology. Aristotle (384-322 b.c.) first attempted a comprehensive classification of animals. His organization and rational development of thought sought to include all things and established an area of natural philosophy that included living things. He was the first to establish some type of hierarchy of animals based on the logic of structure. Roman scholar Pliny the Elder (a.d. 23-79) wrote a major work on natural history. The great physician Galen (129-199?) dissected only animals for his studies of human anatomy, and his works became the standard for use in medicine throughout the Middle Ages.

In the twelfth century, a remarkable development took place in the southern part of Italy, beginning in the town of Salerno. The idea emerged that medical practice should be made a division of the "natural" part of philosophy, as Aristotle had done. By the mid-thirteenth century natural philosophy was one of the liberal arts that all scholars were required to study, and medicine was a part of this. In Italy major universities began to find in the ideas of Galen and Aristotle an encouragement to investigate. Their inquiries were limited to the intellectuals and wealthy, and did not impact the daily lives of people. These were merely seeds that would sprout at the end of the medieval period and bloom during the Renaissance in the fifteenth and sixteenth centuries.

The same driving forces that were part of the discovery period were present in many areas. Explorations of the New World by Christopher Columbus (1451-1506), the Cabots, and others told of new and unusual plants and animals. In 1453 Byzantium, or Constantinople, the capital of Eastern Christendom, fell to the Turks, forcing Greek scholars to move from the East to the West, bringing with them knowledge and access to ancient works. The explosion in the liberal arts with the discovery of Greek manuscripts brought new interest in all areas of classical thinking. Most important of all was the invention of the printing press with movable type by Johann Gutenberg (1398?-1468) around 1455. This enabled scholars to write about their findings and ideas, and using woodcut drawings, they could illustrate what they saw. Add the new availability of paper and the beginning of writing in the language of the people, and the interest in learning would spread rapidly.

Impact

The intellectual energy of the fifteenth and sixteenth centuries touched the field of zoology. The revival of classical works was evoked by artists seeking to realistically and correctly show the body. Leonardo da Vinci (1452-1519) was motivated to study animals, comparing them to the physical form of man. He was the first to describe the homology, or the arrangements of the bones and joints, of a horse. He noted how they were alike and how they differed from the human. Homology would become an important concept in classifying distinct units, and later play a part in the study of evolution. Although Andreas Vesalius (1514-1564), the great anatomist and illustrator, encouraged the new spirit of investigation by dissecting humans, he also used animal parts to show structures such as the kidney. These artists and early anatomists promoted knowledge through dissection and a new spirit of investigation. Francis Bacon (1561-1626) gave increasing emphasis to direct observation and experiment, which caught on in the seventeenth century.

Zurich, Switzerland, one of the centers of the Protestant Reformation, also emerged as a center for the study of the natural sciences or natural philosophy. In this town Konrad Gesner was born and became the godson of Ulrich Zwingli, the great Protestant reformer. Gesner developed as a person of many talents and interests.

When his godfather Zwingli was killed in the battle of Karpel in 1531, he went to Strasbourg to study theology, but soon became tired of this subject and turned to medicine. An eager scholar, he studied at Bourges and Paris, and received his doctorate at Basel in 1541. As a scholar he was very interested in botany, which at the time was closely related to medicine because of the use of plants and herbs in the treatment of disease.

The search for plants led to the next step. Gesner became an ardent traveler and explored extensive areas. He climbed Mount Pilatus overlooking Lake Lucerne and brought back volumes of information on both alpine plants and animals. He found the love of his life in natural history.

Gesner was the first botanist to grasp the importance of floral structures to establish a systematic key of classification of plants. He drew over 1,500 plates himself for his Opera botanica, published in 1551 and 1571.

Several decades before, Aelian had conceived a work on the history of animals. Patterning his organization after the older document, Gesner worked on Historia animalium for years, ending with a 4,500-page volume. The work was immediately recognized by scholars. Using classification similar to his work with plants, Gesner used animal physiology and structure to group specimens. Some consider him to also be the father of veterinary medicine.

Since Gesner was the first naturalist to sketch fossils, he is considered to the first paleontologist. He also studied crystallography and was one of the first to include printed plates of crystals in his works. His drawings were a major addition to texts. He also had many interests. For example, while stories of sea serpents and monsters had been reported for centuries, he printed the first account of such a monsters—based on hearsay—but with a picture.

Guillaume Rondelet was a French naturalist and physician who contributed substantially to zoology through his description of marine animals, primarily those in the Mediterranean Sea. Rondelet published Libri de Piscibus Marinis (1554), or Book of Marine Fish, which contained detailed descriptions of 250 kinds of marine animals. The book had illustrations of each item. He also included whales, marine invertebrates, and seals. He was a professor of anatomy at the University of Montpellier and served the cardinal of that area.

Ulisse Aldrovandi was a nobleman from Bologna who studied mathematics, Latin, law, and philosophy, then went to Padua to study medicine. He became a professor at Bologna and presented very interesting lectures on natural history as a systematic study. He published numerous works, one of which included a detailed observation of day-to-day changes in the developing chick embryo. His museum of biological specimens was classified according to his own system and left to the city of Bologna at his death. He contributed to the development of animal taxonomy by using structure and formation.

The natural theologians of the period were part of the search for organization of zoology. A person dedicated to taxonomy is interested in establishing an orderly account of species. This fit well into the scheme of the natural theologians who believed in an orderly world. John Ray, a devout Puritan, was an academic scholar at Cambridge. With the restoration of the monarchy, Ray hit unfortunate times and was dismissed because he refused to sign the Act of Uniformity in 1662. Some prosperous friends supported him for 43 years while he continued to work as a naturalist. In 1660 Ray began to catalog plants growing around Cambridge and, after completion of that small area, explored the rest of Great Britain. A turning point in his life occurred when he met Francis Willughby, a fellow naturalist who convinced him to undertake a study of the complete natural history of all living things. Ray would investigate all the plants and Willughby, the animals.

The two searched Europe for flora (plants) and fauna (animals). In 1670 Ray had produced his Catalog of English Plants when Willughby suddenly died, leaving Ray to finish both projects. He published Ornithology and History of Fish, giving all the credit and recognition to Willughby.

Ray correlated science with natural theology. He believed that it was obvious that form and function in organic nature demonstrated there must be an all-knowing God.

Many other people who made famous discoveries were interested in animals. William Harvey (1578-1657) demonstrated the circulation of the blood and function of the heart, arteries, and veins. The invention of the microscope by Anton van Leeuwenhoek (1632-1723) assisted in comparing fine structures that previously could not be seen with the unaided eye. Jan Swammerdam (1637-1680) and Marcello Malpighi (1628-1694), who discovered the role of the capillaries, added to the body of information about animals.

The work of the great naturalists culminated in the work of Carl Linnaeus (1707-1778). His binomial system of nomenclature (genus and species) and Systema naturae (1735) marked the beginning of the modern system of classification and helped define zoology as a distinct discipline of study.

EVELYN B. KELLY

Further Reading

Porter, Roy.The Greatest Benefit to Mankind: A Medical History of Humanity. New York: W.W. Norton, 1997.

Wear, A., R. K. French, and I. M. Lonieed, eds. The Medical Renaissance of the Sixteenth Century. Cambridge: Cambridge University Press, 1985.

THE LAST OF THE AUROCHS

Sixteen twenty-seven is the last year that anyone is known to have seen an aurochs in the wild. The last one was seen somewhere in Europe. In that year, cattle became fully domesticated animals; the aurochs was the wild ancestor of all domesticated cattle. The aurochs used to roam freely across large parts of Europe, Asia, and northern Africa. They were large and relatively docile herd animals that were well suited to domestication, and they were domesticated at some time in human prehistory, probably in what is now the Middle East. When domesticated, aurochs entered the service of humanity as draft animals, sources of milk and dairy products, and sources of meat. In fact, cattle today are among the more valuable food animals, providing us with butter, cheese, milk, and, of course, meat. To provide these benefits, we have made the aurochs over into a bevy of cattle breeds, each a specialist in its own way. And, in so doing, we have increased the productivity of our farms.

P. ANDREW KARAM