Zoologists work in all areas of animal life, studying both simple and complex processes. For example, a zoologist might examine the overall structure of a cat or just the microscopic cells in its brain.
Zoologists study the origin and development of animal species, the habits and behavior of animals, and the interaction between animals and their environment. They also do research to learn how animal diseases develop and how traits are passed from generation to generation.
Today, zoology has diversified as a field of science. With new technologies and discoveries, zoology has branched into subjects like biochemistry, genetics, and ecology. These fields deal with different areas of science and apply the acquired knowledge to study the animal kingdom. The main branches of zoology are taxonomy, physiology, and morphology.
Animal-related industries produce food (meats and dairy products), hides, furs, wool, organic fertilizers, and miscellaneous chemical byproducts. There has been a dramatic increase in the productivity of animal husbandry since the 1870s, largely as a consequence of selective breeding and improved animal nutrition.
Since the nineteenth century, the field encompassed by zoology has grown so large that it eventually became divided up into many other fields or branches. Some of these are broad subject areas, like embryology, which studies the development of individual animals, and anatomy that studies the structure of an animal's body.
Zoology includes the study of every type of animal, from the 180-ton blue whale to the one-celled bacteria. Animals make up the largest of the five kingdoms that were created by biologists to organize and describe the living world.
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.
The study and classification of animals as a scientific discipline began with the ancient Greek philosopher Aristotle (384–322 BC) in the fourth century BC. Aristotle's works combined the conventional wisdom of Greek society with his own investigations (which included dissections) and those of others.
Zoology is the study of animal life from molecules to whole animal societies and ecologies, from physiological and reproductive processes that take less than a second to evolutionary histories that extend over many millions of years. Zoology is one of the oldest scientific disciplines and one close to human interest, since animals play an important role as pets, beasts of burden, and livestock.
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.