zoologi

History

Humans have been fascinated by the other members of the animal kingdom throughout history. In early Europe, they gathered up and catalogued descriptions of strange animals from distant lands or deep seas, such as are recorded in the Physiologus and in the works of Albertus Magnus. His work was based largely on the writings of Aristotle. Magnus' De animalibus libri XXVI is not the only volume of his commentaries on Natural History, but it remains one of the most extensive studies of zoological observation published before modern times.^[2]

The disciplinary study of zoology also found root in Arabia and China. Afro-Arab scholar Al-Jahizz (781–868) wrote the Book of Animals, a predecessor to The Origin of Species. Two great Chinese authors in this field were Su Song (1020-1101) and Shen Kuo(1031-1095) of the Song Dynasty period, yet there were many others.

Scientific zoology really started in the 16th century with the awakening of the new spirit of observation and exploration, but for a long time ran a separate course uninfluenced by the progress of the medical studies of anatomy and physiology. The spirit of inquiry which now for the first time became general showed itself in the anatomical schools of the Italian universities of the 16th century and spread fifty years later to the University of Oxford.

The first founded of surviving European academies, the Academia Naturae Curiosorum (1651) confined itself to the description and illustration of the structure of plants and animals; eleven years later, the Royal Society of London was incorporated by royal charter.

A little later the Academy of Sciences of Paris was established by Louis XIV. Collectors and systematisers reached maturity in the latter part of the 18th century in Linnaeus, other anatomists such as John Hunter also set to work to examine anatomically the whole animal kingdom and to classify its members by aid of the results of careful study. Leeuwenhoek, a Dutch tailor and naturalist, introduced another revolution with his construction of the first microscope.

It was not until the 19th century that the microscope was improved accomplished for zoology what some consider to be its most important service. The perfecting of the microscope led to an improved comprehension of cell structure and the establishment of the Cell Theory:

1. That all organisms are either single cells or built of many cells;
2. That all organisms begin their existence as a single cell, which multiplies by binary fission, the products growing in size and multiplying similarly by binary fission; and
3. That the life of a multicellular organism is the sum of the activities of the cells of which it consists and that the processes of life must be studied in and their explanation obtained from an understanding of the chemical and physical changes which go on in each individual cell of living material or protoplasm.

   Systems of classification

Morphography is the systematic exploration, tabulation and characterization of data concerning animals, existing or extinct. It is similar to ethnography. Groups of people who have contributed to the field include past museum-makers of and their modern descendants, the curators and annotators of zoological collections, early explorers and modern naturalist travelers and writers collectors of fossils and paleontologists.

Subfields of zoology

Morphography is the systematic exploration, tabulation and characterization of data concerning animals, existing or extinct. It is similar to ethnography. Groups of people who have contributed to the field include past museum-makers of and their modern descendants, the curators and annotators of zoological collections, early explorers and modern naturalist travelers and writers collectors of fossils and paleontologists.

Subfields of zoology

Although the study of animal life is ancient, its scientific incarnation is relatively modern. This mirrors the transition from natural history to biology at the start of the nineteenth century. Since Hunter and Cuvier, comparative anatomical study has been associated with morphography shapins the modern areas of zoological investigation: anatomy, physiology, histology, embryology, and animal behaviour. Modern zoology first arose in German and British universities. In Britain, Thomas Henry Huxley was a prominent figure. His ideas were centered on the morphology of animals. Many consider him the greatest comparative anatomist of the latter half of the nineteenth century. Similar to Hunter, his courses were composed of lectures and laboratory practical classes in contrast the previous format of lectures only. This system became widely spread.

Gradually zoology expanded beyond Huxley's comparative anatomy to include the following sub-disciplines:

1. Zoography, also known as descriptive zoology, describes animals and their habitats.
2. Comparative anatomy studies the structure of animals.
3. Animal physiology
4. Molecular Biology studies the common genetic and developmental mechanisms of animals and plants
5. Ethology is the study of animal behaviour.
6. Behavioural ecology
7. Evolutionary biology: See of both animals and plants is considered in the articles on evolution, population genetics, heredity, variation, Mendelism, reproduction.
8. Systematics, cladistics, phylogenetics, phylogeography, biogeography and taxonomy classify and group species via common descent and regional associations.
9. The various taxonomically-oriented disciplines such as mammalogy, herpetology, ornithology identify and classify species and study the structures and mechanisms specific to those groups. Entomology is the study of insects, by far the largest group of animals.
10. Palaeontology

History of biology

Biology is a natural science concerned with the study of life and living organisms, including their structure, function, growth, origin, evolution, distribution, and taxonomy.^[1]

Biology is a vast subject containing many subdivisions, topics, and disciplines.

Among the most important topics are five unifying principles that can be said to be the fundamental axioms of modern biology:^[2]

1. Cells are the basic unit of life
2. New species and inherited traits are the product of evolution
3. Genes are the basic unit of heredity
4. An organism will regulate its internal environment to maintain a stable and constant condition
5. Living organisms consume and transform energy.

Subdisciplines of biology are recognized on the basis of the scale at which organisms are studied and the methods used to study them: biochemistry examines the rudimentary chemistry of life; molecular biology studies the complex interactions of systems of biological molecules; cellular biology examines the basic building block of all life, the cell; physiology examines the physical and chemical functions of the tissues, organs, and organ systems of an organism; and ecology examines how various organisms interrelate with their environment

The term biology in its modern sense appears to have been introduced independently by Karl Friedrich Burdach (1800), Gottfried Reinhold Treviranus (Biologie oder Philosophie der lebenden Natur, 1802), and Jean-Baptiste Lamarck (Hydrogéologie, 1802).^[4][5] It was inspired by the Greek word βίος, bios, "life" and the suffix -λογία, -logia, "study of."

Although biology in its modern form is a relatively recent development, sciences related to and included within it have been studied since ancient times. Natural philosophy was studied as early as the ancient civilizations of Mesopotamia, Egypt, the Indian subcontinent, and China. However, the origins of modern biology and its approach to the study of nature are most often traced back to ancient Greece.^[6] While the formal study of medicine dates back to Hippocrates (ca. 460 BC – ca. 370 BC), it was Aristotle (384 BC – 322 BC) who contributed most extensively to the development of biology. Especially important are his History of Animals and other works where he showed naturalist leanings, and later more empirical works that focused on biological causation and the diversity of life. Aristotle's successor at the Lyceum, Theophrastus, wrote a series of books on botany that survived as the most important contribution of antiquity to botany, even into the Middle Ages. Significant advances in the study and development of biology were promoted through the efforts of such Muslim physicians as the Afro-Arab scholar al-Jahiz (781–869) in zoology,^[7] the Kurdish biologist Al-Dinawari (828–896) in botany,^[8] and the Persian physician Rhazes (865–925) in anatomy and physiology. These philosophers elaborated on, expanded, and improved the Greek biological theories and systematics. Medicine was especially well studied by Islamic scholars working in Greek philosopher traditions, while natural history drew heavily on Aristotelian thought, especially in upholding a fixed hierarchy of life.

Biology began to quickly develop and grow with Antony van Leeuwenhoek's dramatic improvement of the microscope. It was then that scholars discovered spermatozoa, bacteria, infusoria and the sheer strangeness and diversity of microscopic life. Investigations by Jan Swammerdam led to new interest in entomology and built the basic techniques of microscopic dissection and staining.^[9]

Advances in microscopy also had a profound impact on biological thinking itself. In the early 19th century, a number of biologists pointed to the central importance of the cell. In 1838 and 1839, Schleiden and Schwann began promoting the ideas that (1) the basic unit of organisms is the cell and (2) that individual cells have all the characteristics of life, although they opposed the idea that (3) all cells come from the division of other cells. Thanks to the work of Robert Remak and Rudolf Virchow, however, by the 1860s most biologists accepted all three tenets of what came to be known as cell theory.^[10]

Meanwhile, taxonomy and classification became a focus in the study of natural history. Carolus 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.^[11] 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 opposed to evolution, Buffon is a key figure in the history of evolutionary thought; his work would influence the evolutionary theories of both Lamarck and Darwin.^[12]

Serious evolutionary thinking originated with the works of Jean-Baptiste Lamarck. However, it was the British naturalist Charles Darwin, combining the biogeographical approach of Humboldt, the uniformitarian geology of Lyell, Thomas Malthus's writings on population growth, and his own morphological expertise, that created a more successful evolutionary theory based on natural selection; similar evidence led Alfred Russel Wallace to independently reach the same conclusions.^[13]

The discovery of the physical representation of heredity came along with evolutionary principles and population genetics. In the 1940s and early 1950s, experiments pointed to DNA as the component of chromosomes that held genes. A focus on new model organisms such as viruses and bacteria, along with the discovery of the double helical structure of DNA in 1953, marked the transition to the era of molecular genetics. From the 1950s to present times, biology has been vastly extended in the molecular domain. The DNA code was cracked by Har Gobind Khorana, Robert W. Holley and Marshall Warren Nirenberg after DNA was proven to contain codons. Finally, the Human Genome Project was launched in 1990 with the goal of mapping the general human genome. This project was essentially completed in 2003, with further analysis still being published. The Human Genome Project was the first step in a globalized effort to incorporate accumulated knowledge of biology into a functional, molecular definition of the human body and the bodies of other organisms.