Biology/Citable Version: Difference between revisions
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== Classification == | |||
The evolutionary trees ([[phylogenetic tree]]s) of the organism being classified. Classification is the province of the disciplines of [[systematics]] and [[alpha taxonomy|taxonomy]]. Taxonomy places organisms in groups called [[taxa]], while systematics seeks to define their relationships with each other. This classification technique has evolved to reflect advances in [[cladistics]] and [[genetics]], shifting the focus from physical similarities and shared characteristics to [[phylogenetics]]. | |||
Traditionally, living things have been divided into five kingdoms: | |||
:[[Monera]] -- [[Protist]]a -- [[Fungus|Fungi]] -- [[Plant]]ae -- [[Animal]]ia | |||
However, many scientists now consider this five-kingdom system to be outdated. Modern alternative classification systems generally begin with the [[three-domain system]]: | |||
:[[Archaea]] (originally Archaebacteria) -- [[Bacterium|Bacteria]] (originally Eubacteria) -- [[Eukaryote|Eukaryota]] | |||
These domains reflect whether the cells have nuclei or not, as well as differences in the cell exteriors. | |||
Further, each kingdom is broken down continuously until each species is separately classified. The order is 1) Kingdom, 2) Phylum, 3) Class, 4) Order, 5) Family, 6) Genus, 7) Species. The scientific name of an organism is obtained from its Genus and Species. For example, humans would be listed as ''Homo sapiens''. Homo would be the Genus and Sapiens is the species. Whenever writing the scientific name of an organism it is proper to capitalize the first letter in the genus and put all of the species in lowercase; in addition the entire term would be put in italics. The term used for classification is called Taxonomy. | |||
There is also a series of intracellular [[parasite]]s that are progressively "less alive" in terms of [[metabolism|metabolic]] activity: | |||
:[[virus (biology)|Viruses]] -- [[Viroid]]s -- [[Prion]]s | |||
==Main topics and discoveries== | |||
{{main|List of biology topics}} | |||
*[[Evolution]] | |||
*[[Common descent]] | |||
*[[Homeostasis]] | |||
Major discoveries in biology include: | Major discoveries in biology include: | ||
* [[Cell theory]] | * [[Cell theory]] | ||
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* [[Evolution]] | * [[Evolution]] | ||
* [[DNA]] | * [[DNA]] | ||
[[Category:Biology| ]] | |||
==Disciplines within biology == | ==Disciplines within biology == |
Revision as of 04:17, 7 November 2006
(from Greek βίος λόγος) The word "Biology" is formed by combining the Greek βίος (bios), meaning 'life', and λόγος (logos), meaning 'study of'. "Biology" in its modern use was probably introduced independently by both Gottfried Reinhold Treviranus (Biologie oder Philosophie der lebenden Natur, 1802) and by Jean-Baptiste Lamarck (Hydrogéologie, 1802). Although the word "biology" is sometimes said to have been coined in 1800 by Karl Friedrich Burdach, it appears in the title of Volume 3 of Michael Christoph Hanov's Philosophiae naturalis sive physicae dogmaticae: Geologia, biologia, phytologia generalis et dendrologia, published in 1766.
Biology is the science of life. Biologists study all aspects of living things, including all of the many life forms on earth and the processes in them that enable life. These basic processes include the making and harnessing of energy, the creation and duplication of the materials that make up the body, the healing of injuries, the reproduction of the organism and many other activities.
Life forms have been of interest to all peoples throughout history, and the roots of biology go back to earliest known mankind. Curiosity about the human body and about the bodies of plants and animals remains active in every human society. Much of the interest in living things stems from a wish to better exploit natural resources and to improve health, and has yielded detailed knowledge about plants and animals used to improve the standard of living. Not all plant and animal lore is biologic science, however. Biology differs from simple interest in plants, animals, and the human body by the use of a systematic approach to study that incorporates an understanding of mathematics, physics, chemistry and the other sciences. Importantly, not all interest in gaining knowlege about living things comes about from a desire to apply it, either from outside or within the field of biology. The core of that desire is sparked by the need to understand the human condition and the nature of the world.
Biology asks some of same questions found in religion and philosophy, questions such as "How did life begin?", and "What features seperate something that is alive from something that is not alive?". The biologist approaches these questions using the scientific method. Therefore, the biologists' answers to such questions differ from the answers found in philosophical and religious works. Whether scientific thinking about such great issues as the origin of life on earth is compatable with religious doctrine is itself a contentious issue. Some great thinkers, such as the physicist Albert Einstein, have found no real conflict on the varying teachings in science and religion, but consider Divinity and the Natural Universe to be one and the same (see Albert Einstein for detailed discussion with references).
There are many independent scientific fields that make up Biology, and all are related. Natural History, (the study of individual species like white-tailed deer, sugar maple trees, and timber wolves) was one of the first areas of biology to develop. In natural history, whole organisms are studied in an attempt to make sense of the order of Nature. When the natural histories of plants and animals are considered in a context of how each affects the other and their environment, then the biologist's focus is on ecology. Some fields of biology are focused on the natural history of living organisms and their interactions within a certain realm of the earth, as in marine biology, and other fields of biology focus on particular aspects of the bodies of living organisms, like their structure (Anatomy) and function (Physiology). Biologic studies of animals fall under the field ofzoology, where as the biologic study of plants is called botany. Medicine and the Health Sciences apply biology to understanding and improving health, and to curing and assuaging the effects of disease. Many of the distinct academic disciplines that make up the field of biology are listed at the bottom of this article along with a brief description. Further information about each is provided through links to other articles within Citizendium.
The Development of Biology
This is a brief outline of selected landmarks in the development of Biology. (For more information please see History of Biology)
- Roots of Biology in the Ancient World
The natural history of plants and animals was the first area of biology to develop.
- Early Biology : The Establishment of the Scientific Method
A workable classification of living things was made practical by Linneas using a form of systematic nomenclature he invented. This nomenclauture not only provides a unique name for each kind of plant and animal, but organizes all of them into a classification scheme that stresses similarities of physical features.
- First Glimpses of the Microscopic World
The features of plants and animals have often been understood on an entirely different levels with technological advances that provided new means for examination. For example, the simple microscope in the hands of Antoni van Leeuwenhoek in the Seventeenth Century, suddenly revealed details of structure in the bodies of organisms that had never even been suspected.Not only was the structure of flesh and plants seen on a new level, but whole new types of organisms were also revealed: micro-organisms that could not be detected with the naked eye. (reference: Anton van Leeuwenhoek." Encyclopedia of World Biography, 2nd ed. 17 Vols. Gale Research, 1998. Reproduced in Biography Resource Center. Farmington Hills, Mich.: Thomson Gale. 2006. http:/galenet.galegroup.com.ezproxy.med.nyu.edu/servlet/BioRC) Further developments led to the modern compound microscope by the end of the 19th century, with much higher resolution and reproducibility, and eventually the late 20th century electron microscopes.
As with every important technological advance in biology, the use of the microsocope led to new ideas about living things. The concept that tissues were composed of cells was clarified, the entire field of microbiology was born, and the ground was prepared for the germ theory of disease, an idea that helped bring the traditional practice of western medicine (sometimes called allopathy) into the field of health science and modern medicine.
Classification
The evolutionary trees (phylogenetic trees) of the organism being classified. Classification is the province of the disciplines of systematics and taxonomy. Taxonomy places organisms in groups called taxa, while systematics seeks to define their relationships with each other. This classification technique has evolved to reflect advances in cladistics and genetics, shifting the focus from physical similarities and shared characteristics to phylogenetics.
Traditionally, living things have been divided into five kingdoms:
However, many scientists now consider this five-kingdom system to be outdated. Modern alternative classification systems generally begin with the three-domain system:
These domains reflect whether the cells have nuclei or not, as well as differences in the cell exteriors.
Further, each kingdom is broken down continuously until each species is separately classified. The order is 1) Kingdom, 2) Phylum, 3) Class, 4) Order, 5) Family, 6) Genus, 7) Species. The scientific name of an organism is obtained from its Genus and Species. For example, humans would be listed as Homo sapiens. Homo would be the Genus and Sapiens is the species. Whenever writing the scientific name of an organism it is proper to capitalize the first letter in the genus and put all of the species in lowercase; in addition the entire term would be put in italics. The term used for classification is called Taxonomy.
There is also a series of intracellular parasites that are progressively "less alive" in terms of metabolic activity:
Main topics and discoveries
Major discoveries in biology include:
Disciplines within biology
- Anatomy: The study of structure
- Biochemistry: The chemistry of living things is a field of both biology and chemistry
- Cell Biology: The study of the components of cells
- Genetics: The study of the inheritance of characteristics, genes and DNA
- Marine Biology: The study of life in the seas and oceans
- Behavior:
- Biodiversity:
- Biogeography:
- Botany:
- Developmental biology:
- Ecology:
- Ethology:
- Evolutionary biology:
- Molecular biology:
- Physiology:
- Zoology:
Selected External links
The following links have been reviewed and are recommended because, at the time of their inclusion, they provided accurate information and portals to additional excellent web resources . Many other excellent links have been omitted through no fault of their own.
Plain & Technical Language
- The American Institute of Biological Sciences (ABIBS) Virtual Library is free to all visitors
- The Bio-Web reviews and gives access to information in Cell and Molecular Biology, includes "news" in plain language
- Cell and Molecular Biology Online is a resource for professionals that includes links and some information for all
- Kimball's Biology Pages represent an online biology textbook