Biology deals with the study of life and organisms.

Biology is the natural science that studies life and living organisms, including their physical structure, chemical processes, molecular interactions, physiological mechanisms, development and evolution.[1] Despite the complexity of the science, there are certain unifying concepts that consolidate it into a single, coherent field. Biology recognizes the cell as the basic unit of life, genes as the basic unit of heredity, and evolution as the engine that propels the creation and extinction of species. Living organisms are open systems that survive by transforming energy and decreasing their local entropy[2] to maintain a stable and vital condition defined as homeostasis.[3]

Sub-disciplines of biology are defined by the research methods employed and the kind of system studied: theoretical biology uses mathematical methods to formulate quantitative models while experimental biology performs empirical experiments to test the validity of proposed theories and understand the mechanisms underlying life and how it appeared and evolved from non-living matter about 4 billion years ago through a gradual increase in the complexity of the system.[4][5][6] See branches of biology.


A drawing of a fly from facing up, with wing detail
A Diagram of a fly from Robert Hooke's innovative Micrographia, 1665
Ernst Haeckel's pedigree of Man family tree from Evolution of Man
Ernst Haeckel's Tree of Life (1879)

The term biology is derived from the Greek word βίος, bios, "life" and the suffix -λογία, -logia, "study of."[7][8] The Latin-language form of the term first appeared in 1736 when Swedish scientist Carl Linnaeus (Carl von Linné) used biologi in his Bibliotheca Botanica. It was used again in 1766 in a work entitled Philosophiae naturalis sive physicae: tomus III, continens geologian, biologian, phytologian generalis, by Michael Christoph Hanov, a disciple of Christian Wolff. The first German use, Biologie, was in a 1771 translation of Linnaeus' work. In 1797, Theodor Georg August Roose used the term in the preface of a book, Grundzüge der Lehre van der Lebenskraft. Karl Friedrich Burdach used the term in 1800 in a more restricted sense of the study of human beings from a morphological, physiological and psychological perspective (Propädeutik zum Studien der gesammten Heilkunst). The term came into its modern usage with the six-volume treatise Biologie, oder Philosophie der lebenden Natur (1802–22) by Gottfried Reinhold Treviranus, who announced:[9]

The objects of our research will be the different forms and manifestations of life, the conditions and laws under which these phenomena occur, and the causes through which they have been effected. The science that concerns itself with these objects we will indicate by the name biology [Biologie] or the doctrine of life [Lebenslehre].

Although modern biology 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.[10][11] While the formal study of medicine dates back to Hippocrates (ca. 460–370 BC), it was Aristotle (384–322 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 the plant sciences, even into the Middle Ages.[12]

Scholars of the medieval Islamic world who wrote on biology included al-Jahiz (781–869), Al-Dīnawarī (828–896), who wrote on botany,[13] and Rhazes (865–925) who wrote on anatomy and physiology. 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 Anton van Leeuwenhoek's dramatic improvement of the microscope. It was then that scholars discovered spermatozoa, bacteria, infusoria and the diversity of microscopic life. Investigations by Jan Swammerdam led to new interest in entomology and helped to develop the basic techniques of microscopic dissection and staining.[14]

Advances in microscopy also had a profound impact on biological thinking. In the early 19th century, a number of biologists pointed to the central importance of the cell. Then, in 1838, Schleiden and Schwann began promoting the now universal 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.[15][16]

Meanwhile, taxonomy and classification became the focus of natural historians. 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.[17] Georges-Louis Leclerc, Comte de Buffon, treated species as artificial categories and living forms as malleable—even suggesting the possibility of common descent. Although he was opposed to evolution, Buffon is a key figure in the history of evolutionary thought; his work influenced the evolutionary theories of both Lamarck and Darwin.[18]

Serious evolutionary thinking originated with the works of Jean-Baptiste Lamarck, who was the first to present a coherent theory of evolution.[19] He posited that evolution was the result of environmental stress on properties of animals, meaning that the more frequently and rigorously an organ was used, the more complex and efficient it would become, thus adapting the animal to its environment. Lamarck believed that these acquired traits could then be passed on to the animal's offspring, who would further develop and perfect them.[20] However, it was the British naturalist Charles Darwin, combining the biogeographical approach of Humboldt, the uniformitarian geology of Lyell, Malthus's writings on population growth, and his own morphological expertise and extensive natural observations, who forged a more successful evolutionary theory based on natural selection; similar reasoning and evidence led Alfred Russel Wallace to independently reach the same conclusions.[21][22] Although it was the subject of controversy (which continues to this day), Darwin's theory quickly spread through the scientific community and soon became a central axiom of the rapidly developing science of biology.

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 the trait-carrying units that had become known as genes. A focus on new kinds of 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 genetic code was cracked by Har Gobind Khorana, Robert W. Holley and Marshall Warren Nirenberg after DNA was understood 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,[23] 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.

Other Languages
Afrikaans: Biologie
Alemannisch: Biologie
አማርኛ: ሥነ ሕይወት
Аҧсшәа: Абиологиа
العربية: علم الأحياء
aragonés: Biolochía
armãneashti: Biologie
arpetan: Biologia
অসমীয়া: জীৱ বিজ্ঞান
asturianu: Bioloxía
azərbaycanca: Biologiya
تۆرکجه: جانلی بیلیم
Bahasa Banjar: Biologi
Bân-lâm-gú: Seng-bu̍t-ha̍k
Basa Banyumasan: Biologi
башҡортса: Биология
беларуская: Біялогія
беларуская (тарашкевіца)‎: Біялёгія
भोजपुरी: जीव बिज्ञान
Bislama: Baeoloji
български: Биология
Boarisch: Biologie
bosanski: Biologija
brezhoneg: Bevoniezh
буряад: Биологи
català: Biologia
Чӑвашла: Биологи
Cebuano: Biyolohiya
čeština: Biologie
Chamoru: Bioloyia
chiShona: Unenamhenyu
corsu: Biologia
Cymraeg: Bywydeg
dansk: Biologi
Deutsch: Biologie
ދިވެހިބަސް: ދިރުމާބެހޭ އިލްމު
eesti: Bioloogia
Ελληνικά: Βιολογία
español: Biología
Esperanto: Biologio
estremeñu: Biologia
euskara: Biologia
Fiji Hindi: Jiu vigyan
føroyskt: Lívfrøði
français: Biologie
Frysk: Biology
furlan: Biologjie
Gàidhlig: Bith-eòlas
galego: Bioloxía
Gĩkũyũ: Bayorojĩ
ગુજરાતી: જીવવિજ્ઞાન
客家語/Hak-kâ-ngî: Sâng-vu̍t-ho̍k
хальмг: Биолог
한국어: 생물학
Hawaiʻi: Kālaimeaola
Արեւմտահայերէն: Կենսաբանութիւն
hornjoserbsce: Biologija
hrvatski: Biologija
Ilokano: Biolohia
Bahasa Indonesia: Biologi
interlingua: Biologia
Interlingue: Biologie
ᐃᓄᒃᑎᑐᑦ/inuktitut: ᐆᒪᔅᓱᓯᖃᕐᑐᓕᕆᓂᖅ
Ирон: Биологи
isiXhosa: IBayoloji
íslenska: Líffræði
italiano: Biologia
עברית: ביולוגיה
Jawa: Biologi
kalaallisut: Uumassusililerineq
Kapampangan: Biologia
ქართული: ბიოლოგია
kaszëbsczi: Biologijô
қазақша: Биология
kernowek: Bywonieth
Kiswahili: Biolojia
Kreyòl ayisyen: Biyoloji
kurdî: Biyolojî
Кыргызча: Биология
Ladino: Biolojiya
لۊری شومالی: زئشت
Latina: Biologia
latviešu: Bioloģija
Lëtzebuergesch: Biologie
лезги: Биология
lietuvių: Biologija
Ligure: Biologia
Limburgs: Biologie
Lingua Franca Nova: Biolojia
Livvinkarjala: Biolougii
la .lojban.: mivyske
Luganda: Essomabiramu
lumbaart: Biolojia
magyar: Biológia
македонски: Биологија
Malagasy: Biolojia
მარგალური: ბიოლოგია
Bahasa Melayu: Biologi
Mìng-dĕ̤ng-ngṳ̄: Sĕng-ŭk-hŏk
Mirandés: Biologie
монгол: Амин судлал
မြန်မာဘာသာ: ဇီဝဗေဒ
Nāhuatl: Yolizmatiliztli
Nederlands: Biologie
Nedersaksies: Biologie
नेपाली: जीवशास्त्र
नेपाल भाषा: जीवशास्त्र
日本語: 生物学
Napulitano: Biologgia
нохчийн: Биологи
Nordfriisk: Biologii
Norfuk / Pitkern: Biiolojii
norsk: Biologi
norsk nynorsk: Biologi
Nouormand: Biologie
Novial: Biologia
occitan: Biologia
олык марий: Биологий
Oromoo: Baayoloojii
oʻzbekcha/ўзбекча: Biologiya
ਪੰਜਾਬੀ: ਜੀਵ ਵਿਗਿਆਨ
Pälzisch: Biologie
پنجابی: جیون پڑھت
Papiamentu: Biologia
Patois: Bailoji
ភាសាខ្មែរ: ជីវវិទ្យា
Piemontèis: Biologìa
Tok Pisin: Save long laip
Plattdüütsch: Biologie
polski: Biologia
português: Biologia
Qaraqalpaqsha: Biologiya
qırımtatarca: Ayatiyat
română: Biologie
rumantsch: Biologia
Runa Simi: Kawsay yachay
русиньскый: Біолоґія
русский: Биология
саха тыла: Биология
Gagana Samoa: Paiolo
संस्कृतम्: जीवशास्त्रम्
sardu: Biologia
Scots: Biology
Seeltersk: Biologie
Sesotho sa Leboa: Thutaphedi
shqip: Biologjia
sicilianu: Bioluggìa
Simple English: Biology
سنڌي: حياتيات
SiSwati: Ibhayoloji
slovenčina: Biológia
slovenščina: Biologija
Soomaaliga: Bayoloji
کوردی: ژینناسی
српски / srpski: Биологија
srpskohrvatski / српскохрватски: Biologija
Basa Sunda: Biologi
suomi: Biologia
svenska: Biologi
Tagalog: Biyolohiya
தமிழ்: உயிரியல்
Taqbaylit: Tasnudert
татарча/tatarça: Биология
tetun: Biolojia
ትግርኛ: ባዮሎጂ
тоҷикӣ: Зистшиносӣ
Türkçe: Biyoloji
Türkmençe: Biologiýa
Thuɔŋjäŋ: Piöcëpïr
ᨅᨔ ᨕᨘᨁᨗ: ᨅᨗᨕᨚᨒᨚᨁᨗ
українська: Біологія
اردو: حیاتیات
ئۇيغۇرچە / Uyghurche: بىئولوگىيە
vèneto: Biołogia
Tiếng Việt: Sinh học
Volapük: Lifav
Võro: Bioloogia
文言: 生物學
West-Vlams: Biologie
Winaray: Biyolohiya
吴语: 生物學
Xitsonga: Ntivo-Vutomi
ייִדיש: ביאלאגיע
粵語: 生物學
Zazaki: Biyolociye
Zeêuws: Biologie
žemaitėška: Bioluogėjė
中文: 生物学