Zoology (/zoʊˈɒlədʒi, zu-/)[note 1] is the branch of biology that studies the animal kingdom, including the structure, embryology, evolution, classification, habits, and distribution of all animals, both living and extinct, and how they interact with their ecosystems. The term is derived from Ancient Greek ζῷον, zōion, i.e. "animal" and λόγος, logos, i.e. "knowledge, study".
The history of zoology traces the study of the animal kingdom from ancient to modern times. Although the concept of zoology as a single coherent field arose much later, the zoological sciences emerged from natural history reaching back to the biological works of Aristotle and Galen in the ancient Greco-Roman world. This ancient work was further developed in the Middle Ages by Muslim physicians and scholars such as Albertus Magnus. During the Renaissance and early modern period, zoological thought was revolutionized in Europe by a renewed interest in empiricism and the discovery of many novel organisms. Prominent in this movement were Vesalius and William Harvey, who used experimentation and careful observation in physiology, and naturalists such as Carl Linnaeus, Jean-Baptiste Lamarck, and Buffon who began to classify the diversity of life and the fossil record, as well as the development and behavior of organisms. Microscopy revealed the previously unknown world of microorganisms, laying the groundwork for cell theory. The growing importance of natural theology, partly a response to the rise of mechanical philosophy, encouraged the growth of natural history (although it entrenched the argument from design).
Over the 18th, 19th, and 20th centuries, zoology became an increasingly professional scientific discipline. Explorer-naturalists such as Alexander von Humboldt investigated the interaction between organisms and their environment, and the ways this relationship depends on geography, laying the foundations for biogeography, ecology and ethology. Naturalists began to reject essentialism and consider the importance of extinction and the mutability of species. Cell theory provided a new perspective on the fundamental basis of life.
These developments, as well as the results from embryology and paleontology, were synthesized in Charles Darwin's theory of evolution by natural selection. In 1859, Darwin placed the theory of organic evolution on a new footing, by his discovery of a process by which organic evolution can occur, and provided observational evidence that it had done so.
Darwin gave a new direction to morphology and physiology, by uniting them in a common biological theory: the theory of organic evolution. The result was a reconstruction of the classification of animals upon a genealogical basis, fresh investigation of the development of animals, and early attempts to determine their genetic relationships. The end of the 19th century saw the fall of spontaneous generation and the rise of the germ theory of disease, though the mechanism of inheritance remained a mystery. In the early 20th century, the rediscovery of Mendel's work led to the rapid development of genetics, and by the 1930s the combination of population genetics and natural selection in the modern synthesis created evolutionary biology.
Cell biology studies the structural and physiological properties of cells, including their behavior, interactions, and environment. This is done on both the microscopic and molecular levels, for single-celled organisms such as bacteria as well as the specialized cells in multicellular organisms such as humans. Understanding the structure and function of cells is fundamental to all of the biological sciences. The similarities and differences between cell types are particularly relevant to molecular biology.
Anatomy considers the forms of macroscopic structures such as organs and organ systems. It focuses on how organs and organ systems work together in the bodies of humans and animals, in addition to how they work independently. Anatomy and cell biology are two studies that are closely related, and can be categorized under "structural" studies.
Physiology studies the mechanical, physical, and biochemical processes of living organisms by attempting to understand how all of the structures function as a whole. The theme of "structure to function" is central to biology. Physiological studies have traditionally been divided into plant physiology and animal physiology, but some principles of physiology are universal, no matter what particular organism is being studied. For example, what is learned about the physiology of yeast cells can also apply to human cells. The field of animal physiology extends the tools and methods of human physiology to non-human species. Physiology studies how for example nervous, immune, endocrine, respiratory, and circulatory systems, function and interact.
Evolutionary research is concerned with the origin and descent of species, as well as their change over time, and includes scientists from many taxonomically oriented disciplines. For example, it generally involves scientists who have special training in particular organisms such as mammalogy, ornithology, herpetology, or entomology, but use those organisms as systems to answer general questions about evolution.
Evolutionary biology is partly based on paleontology, which uses the fossil record to answer questions about the mode and tempo of evolution, and partly on the developments in areas such as population genetics and evolutionary theory. Following the development of DNA fingerprinting techniques in the late 20th century, the application of these techniques in zoology has increased the understanding of animal populations. In the 1980s, developmental biology re-entered evolutionary biology from its initial exclusion from the modern synthesis through the study of evolutionary developmental biology. Related fields often considered part of evolutionary biology are phylogenetics, systematics, and taxonomy.
Scientific classification in zoology, is a method by which zoologists group and categorize organisms by biological type, such as genus or species. Biological classification is a form of scientific taxonomy. Modern biological classification has its root in the work of Carl Linnaeus, who grouped species according to shared physical characteristics. These groupings have since been revised to improve consistency with the Darwinian principle of common descent. Molecular phylogenetics, which uses DNA sequences as data, has driven many recent revisions and is likely to continue to do so. Biological classification belongs to the science of zoological systematics.
Many scientists now consider the five-kingdom system outdated. Modern alternative classification systems generally start with the three-domain system: Archaea (originally Archaebacteria); Bacteria (originally Eubacteria); Eukaryota (including protists, fungi, plants, and animals) These domains reflect whether the cells have nuclei or not, as well as differences in the chemical composition of the cell exteriors.
Further, each kingdom is broken down recursively until each species is separately classified. The order is: Domain; kingdom; phylum; class; order; family; genus; species. The scientific name of an organism is generated from its genus and species. For example, humans are listed as Homo sapiens. Homo is the genus, and sapiens the specific epithet, both of them combined make up the species name. When writing the scientific name of an organism, it is proper to capitalize the first letter in the genus and put all of the specific epithet in lowercase. Additionally, the entire term may be italicized or underlined.
The dominant classification system is called the Linnaean taxonomy. It includes ranks and binomial nomenclature. The classification, taxonomy, and nomenclature of zoological organisms is administered by the International Code of Zoological Nomenclature. A merging draft, BioCode, was published in 1997 in an attempt to standardize nomenclature, but has yet to be formally adopted.
Ethology is the scientific and objective study of animal behavior under natural conditions, as opposed to behaviourism, which focuses on behavioral response studies in a laboratory setting. Ethologists have been particularly concerned with the evolution of behavior and the understanding of behavior in terms of the theory of natural selection. In one sense, the first modern ethologist was Charles Darwin, whose book, The Expression of the Emotions in Man and Animals, influenced many future ethologists.
Biogeography studies the spatial distribution of organisms on the Earth, focusing on topics like plate tectonics, climate change, dispersal and migration, and cladistics. The creation of this study is widely accredited to Alfred Russel Wallace, a British biologist who had some of his work jointly published with Charles Darwin.
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 19th century. Since Hunter and Cuvier, comparative anatomical study has been associated with morphography, shaping the modern areas of zoological investigation: anatomy, physiology, histology, embryology, teratology and ethology. 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 19th century. Similar to Hunter, his courses were composed of lectures and laboratory practical classes in contrast to the previous format of lectures only.
Gradually zoology expanded beyond Huxley's comparative anatomy to include the following sub-disciplines:
2 : the scientific and objective study of animal behaviour especially under natural conditions
Anacondas or water boas are a group of large snakes of the genus Eunectes. They are found in tropical South America. Four species are currently recognized.Bass (fish)
Bass () is a name shared by many species of fish. The term encompasses both freshwater and marine species, all belonging to the large order Perciformes, or perch-like fishes. The word bass comes from Middle English bars, meaning "perch".Cannibalism
Cannibalism involves consuming all or part of another individual of the same species as food. To consume the same species, or show cannibalistic behavior, is a common ecological interaction in the animal kingdom, and has been recorded in more than 1,500 species. Human cannibalism is well-documented, both in ancient and in recent times.The rate of cannibalism increases in nutritionally-poor environments as individuals turn to other conspecific individuals as an additional food-source. Cannibalism regulates population numbers, whereby resources such as food, shelter and territory become more readily available with the decrease of potential competition. Although it may benefit the individual, it has been shown that the presence of cannibalism decreases the expected survival rate of the whole population and increases the risk of consuming a relative. Other negative effects may include the increased risk of pathogen transmission as the encounter rate of hosts increases. Cannibalism, however, does not—as once believed—occur only as a result of extreme food shortage or of artificial/unnatural conditions, but may also occur under natural conditions in a variety of species.Cannibalism seems especially prevalent in aquatic ecosystems, in which up to approximately 90% of the organisms engage in cannibalistic activity at some point in their life-cycle. Cannibalism is not restricted to carnivorous species: it also occurs in herbivores and in detritivores. Sexual cannibalism normally involves the consumption of the male by the female individual before, during or after copulation. Other forms of cannibalism include size-structured cannibalism and intrauterine cannibalism.
Behavioural, physiological and morphological adaptations have evolved to decrease the rate of cannibalism in individual species.Cardinal (bird)
Cardinals, in the family Cardinalidae, are passerine birds found in North and South America. They are also known as cardinal-grosbeaks and cardinal-buntings.
The South American cardinals in the genus Paroaria are placed in the Tanager family Thraupidae. Contrariwise, DNA analysis of the genera Piranga (which includes the scarlet tanager, summer tanager, and western tanager), Chlorothraupis, and Habia showed their closer relationship to the cardinal family. They have been reassigned to that family by the American Ornithological Society.Class (biology)
In biological classification, class (Latin: classis) is a taxonomic rank, as well as a taxonomic unit, a taxon, in that rank. Other well-known ranks in descending order of size are life, domain, kingdom, phylum, order, family, genus, and species, with class fitting between phylum and order.Crow
A crow is a bird of the genus Corvus, or more broadly a synonym for all of Corvus. The term "crow" is used as part of the common name of many species. Species with the word "crow" in their common name include:
Corvus albus – pied crow (Central African coasts to southern Africa)
Corvus bennetti – little crow (Australia)
Corvus brachyrhynchos – American crow (United States, southern Canada, northern Mexico)
Corvus capensis – Cape crow or Cape rook (Eastern and southern Africa)
Corvus caurinus – northwestern crow (Olympic peninsula to southwest Alaska)
Corvus cornix – hooded crow (Northern and Eastern Europe and Northern Africa)
Corvus corone – carrion crow (Europe and eastern Asia)
Corvus edithae – Somali crow (eastern Africa)
Corvus enca – slender-billed crow (Malaysia, Borneo, Indonesia)
Corvus florensis – Flores crow (Flores Island)
Corvus fuscicapillus – brown-headed crow (New Guinea)
Corvus hawaiiensis (formerly C. tropicus) – Hawaiian crow (Hawaii)
Corvus imparatus – Tamaulipas crow (Gulf of Mexico coast)
Corvus insularis – Bismarck crow (Bismarck Archipelago, Papua New Guinea)
Corvus jamaicensis – Jamaican crow (Jamaica)
Corvus kubaryi – Mariana crow or aga (Guam, Rota)
Corvus leucognaphalus – white-necked crow (Haiti, Dominican Republic, Puerto Rico)
Corvus macrorhynchos – jungle crow (Eastern Asia, Himalayas, Philippines)
Corvus macrorhynchos macrorhynchos – large-billed crow
Corvus macrorhynchos levaillantii – eastern jungle crow (India, Burma)
Corvus macrorhynchos culminatus – Indian jungle crow
Corvus meeki – Bougainville crow or Solomon Islands crow (Northern Solomon Islands)
Corvus moneduloides – New Caledonian crow (New Caledonia, Loyalty Islands)
Corvus nasicus – Cuban crow (Cuba, Isla de la Juventud, Grand Caicos Island)
Corvus orru – Torresian crow or Australian crow (Australia, New Guinea and nearby islands)
Corvus ossifragus – fish crow (Southeastern U.S. coast)
Corvus palmarum – palm crow (Cuba, Haiti, Dominican Republic)
Corvus ruficolis edithae – Somali crow or dwarf raven (Northeast Africa)
Corvus sinaloae – Sinaloan crow (Pacific coast from Sonora to Colima)
Corvus splendens – house crow or Indian house crow (Indian subcontinent, Middle East, east Africa)
Corvus torquatus – collared crow (Eastern China, south into Vietnam)
Corvus tristis – grey crow or Bare-faced crow (New Guinea and neighboring islands)
Corvus typicus – piping crow or Celebes pied crow (Sulawesi, Muna, Butung)
Corvus unicolor – Banggai crow (Banggai Island)
Corvus validus – long-billed crow (Northern Moluccas)
Corvus violaceus – violet crow (Seram) – recent split from slender-billed crow
Corvus woodfordi – white-billed crow or Solomon Islands crow (Southern Solomon Islands)Larva
A larva (plural: larvae ) is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle.
The larva's appearance is generally very different from the adult form (e.g. caterpillars and butterflies) including different unique structures and organs that do not occur in the adult form. Their diet may also be considerably different.
Larvae are frequently adapted to environments separate from adults. For example, some larvae such as tadpoles live almost exclusively in aquatic environments, but can live outside water as adult frogs. By living in a distinct environment, larvae may be given shelter from predators and reduce competition for resources with the adult population.
Animals in the larval stage will consume food to fuel their transition into the adult form. In some species like barnacles, adults are immobile but their larvae are mobile, and use their mobile larval form to distribute themselves.
Some larvae are dependent on adults to feed them. In many eusocial Hymenoptera species, the larvae are fed by female workers. In Ropalidia marginata (a paper wasp) the males are also capable of feeding larvae but they are much less efficient, spending more time and getting less food to the larvae.The larvae of some species (for example, some newts) can become pubescent and do not develop further into the adult form. This is a type of neoteny.
It is a misunderstanding that the larval form always reflects the group's evolutionary history. This could be the case, but often the larval stage has evolved secondarily, as in insects. In these cases the larval form may differ more than the adult form from the group's common origin.Mammal Species of the World
Mammal Species of the World: A Taxonomic and Geographic Reference is a standard reference work in mammalogy giving descriptions and bibliographic data for the known species of mammals. It is now in its third edition, published in late 2005, which was edited by Don E. Wilson and DeeAnn M. Reeder.An online version is hosted by Bucknell University, from which the names of the species can be downloaded as a custom dictionary. A partial online version is available at Google Books (see "External links" below).
The Checklist Committee is charged with compiling and updating MSW. In its Annual Report for 2015, the Committee noted that it is under contract with Johns Hopkins Press for the 4th edition of MSW, which will be edited by DeeAnn M. Reeder and Kristofer M. Helgen. The database has been made editable for the authors, leading to more frequent website updates. The publication was due in 2017.Porcupine
Porcupines are rodents with a coat of sharp spines, or quills, that protect against predators. The term covers two families of animals, the Old World porcupines of family Hystricidae, and the New World porcupines of family Erethizontidae. Both families belong to the infraorder Hystricognathi within the profoundly diverse order Rodentia and display superficially similar coats of quills: despite this, the two groups are distinct from each other and are not closely related to each other within the Hystricognathi.
The Old World porcupines live in southern Europe, Asia (western and southern), and most of Africa. They are large, terrestrial, and strictly nocturnal. In taxonomic terms, they form the family Hystricidae.
The New World porcupines are indigenous to North America and northern South America. They live in wooded areas and can climb trees, where some species spend their entire lives. They are less strictly nocturnal than their Old World relatives, and generally smaller. In taxonomic terms, they form the family Erethizontidae.
Most porcupines are about 60–90 cm (25–36 in) long, with an 20–25 cm (8–10 in) long tail. Weighing 5–16 kg (12–35 lb), they are rounded, large, and slow, and use aposematic strategy of defense. Porcupines occur in various shades of brown, gray, and white. Porcupines' spiny protection resembles that of the unrelated erinaceomorph hedgehogs and Australian monotreme echidnas.Pythonidae
The Pythonidae, commonly known simply as pythons, from the Greek word python (πυθων), are a family of nonvenomous snakes found in Africa, Asia, and Australia. Among its members are some of the largest snakes in the world. Eight genera and 31 species are currently recognized.Scale (anatomy)
In most biological nomenclature, a scale (Greek λεπίς lepis, Latin squama) is a small rigid plate that grows out of an animal's skin to provide protection. In lepidopteran (butterfly and moth) species, scales are plates on the surface of the insect wing, and provide coloration. Scales are quite common and have evolved multiple times through convergent evolution, with varying structure and function.
Scales are generally classified as part of an organism's integumentary system. There are various types of scales according to shape and to class of animal.Specific name (zoology)
In zoological nomenclature, the specific name (also specific epithet or species epithet) is the second part (the second name) within the scientific name of a species (a binomen). The first part of the name of a species is the name of the genus or the generic name. The rules and regulations governing the giving of a new species name are explained in the article species description.
The scientific name for humans is Homo sapiens, which is the species name, consisting of two names: Homo is the "generic name" (the name of the genus) and sapiens is the "specific name".Synonym (taxonomy)
In scientific nomenclature, a synonym is a scientific name that applies to a taxon that (now) goes by a different scientific name, although the term is used somewhat differently in the zoological code of nomenclature. For example, Linnaeus was the first to give a scientific name (under the currently used system of scientific nomenclature) to the Norway spruce, which he called Pinus abies. This name is no longer in use: it is now a synonym of the current scientific name, Picea abies.
Unlike synonyms in other contexts, in taxonomy a synonym is not interchangeable with the name of which it is a synonym. In taxonomy, synonyms are not equals, but have a different status. For any taxon with a particular circumscription, position, and rank, only one scientific name is considered to be the correct one at any given time (this correct name is to be determined by applying the relevant code of nomenclature). A synonym cannot exist in isolation: it is always an alternative to a different scientific name. Given that the correct name of a taxon depends on the taxonomic viewpoint used (resulting in a particular circumscription, position and rank) a name that is one taxonomist's synonym may be another taxonomist's correct name (and vice versa).
Synonyms may arise whenever the same taxon is described and named more than once, independently. They may also arise when existing taxa are changed, as when two taxa are joined to become one, a species is moved to a different genus, a variety is moved to a different species, etc. Synonyms also come about when the codes of nomenclature change, so that older names are no longer acceptable; for example, Erica herbacea L. has been rejected in favour of Erica carnea L. and is thus its synonym.Taxonomic rank
In biological classification, taxonomic rank is the relative level of a group of organisms (a taxon) in a taxonomic hierarchy. Examples of taxonomic ranks are species, genus, family, order, class, phylum, kingdom, domain, etc.
A given rank subsumes under it less general categories, that is, more specific descriptions of life forms. Above it, each rank is classified within more general categories of organisms and groups of organisms related to each other through inheritance of traits or features from common ancestors. The rank of any species and the description of its genus is basic; which means that to identify a particular organism, it is usually not necessary to specify ranks other than these first two.Consider a particular species, the red fox, Vulpes vulpes: the next rank above, the genus Vulpes, comprises all the "true" foxes. Their closest relatives are in the immediately higher rank, the family Canidae, which includes dogs, wolves, jackals, and all foxes; the next higher rank, the order Carnivora, includes caniforms (bears, seals, weasels, skunks, raccoons and all those mentioned above), and feliforms (cats, civets, hyenas, mongooses). Carnivorans are one group of the hairy, warm-blooded, nursing members of the class Mammalia, which are classified among animals with backbones in the phylum Chordata, and with them among all animals in the kingdom Animalia. Finally, at the highest rank all of these are grouped together with all other organisms possessing cell nuclei in the domain Eukarya.
The International Code of Zoological Nomenclature defines rank as: "The level, for nomenclatural purposes, of a taxon in a taxonomic hierarchy (e.g. all families are for nomenclatural purposes at the same rank, which lies between superfamily and subfamily)."The Raffles Bulletin of Zoology
The Raffles Bulletin of Zoology is a peer-reviewed open-access scientific journal published by the Lee Kong Chian Natural History Museum in Singapore. It covers the taxonomy, ecology, and conservation of Southeast Asian fauna. Supplements are published as and when funding permits and may cover topics that extend beyond the normal scope of the journal depending on the targets of the funding agency. It was established as the Bulletin of the Raffles Museum in 1928 and renamed Bulletin of the National Museum of Singapore in 1961, before obtaining its current title in 1971.Tribe (biology)
In biology, a tribe is a taxonomic rank above genus, but below family and subfamily. It is sometimes subdivided into subtribes.
In zoology, the standard ending for the name of a zoological tribe is "-ini". Examples include the tribes Caprini (goat-antelopes), Hominini (hominins), Bombini (bumblebees), and Thunnini (tunas). The tribe Hominini is divided into subtribes by some scientists; subtribe Hominina then comprises "humans". The standard ending for the name of a zoological subtribe is "-ina".
In botany, the standard ending for the name of a botanical tribe is "-eae". Examples include the tribes Acalypheae and Hyacintheae. The tribe Hyacintheae is divided into subtribes, including the subtribe Massoniinae. The standard ending for the name of a botanical subtribe is "-inae".
In bacteriology, the form of tribe names is as in botany, e.g., Pseudomonadeae, based on the genus name Pseudomonas.Type (biology)
In biology, a type is a particular specimen (or in some cases a group of specimens) of an organism to which the scientific name of that organism is formally attached. In other words, a type is an example that serves to anchor or centralize the defining features of that particular taxon. In older usage (pre-1900 in botany), a type was a taxon rather than a specimen.A taxon is a scientifically named grouping of organisms with other like organisms, a set that includes some organisms and excludes others, based on a detailed published description (for example a species description) and on the provision of type material, which is usually available to scientists for examination in a major museum research collection, or similar institution.Type species
In zoological nomenclature, a type species (species typica) is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the species that contains the biological type specimen(s). A similar concept is used for suprageneric groups called a type genus.
In botanical nomenclature, these terms have no formal standing under the code of nomenclature, but are sometimes borrowed from zoological nomenclature. In botany, the type of a genus name is a specimen (or, rarely, an illustration) which is also the type of a species name. The species name that has that type can also be referred to as the type of the genus name. Names of genus and family ranks, the various subdivisions of those ranks, and some higher-rank names based on genus names, have such types.In bacteriology, a type species is assigned for each genus.Every named genus or subgenus in zoology, whether or not currently recognized as valid, is theoretically associated with a type species. In practice, however, there is a backlog of untypified names defined in older publications when it was not required to specify a type.Zootaxa
Zootaxa is a peer-reviewed scientific mega journal for animal taxonomists. It is published by Magnolia Press (Auckland, New Zealand). The journal was established by Zhi-Qiang Zhang in 2001 and new issues are published multiple times a week. As of December 2012 more than 26,300 new taxa have been described in the journal. Print and online versions are available.
|Hierarchy of life|
Zoos, aquariums and aviaries
|Types of zoos|