1.
Taxonomy (biology)
–
Taxonomy is the science of defining groups of biological organisms on the basis of shared characteristics and giving names to those groups. The exact definition of taxonomy varies from source to source, but the core of the remains, the conception, naming. There is some disagreement as to whether biological nomenclature is considered a part of taxonomy, the broadest meaning of taxonomy is used here. The word taxonomy was introduced in 1813 by Candolle, in his Théorie élémentaire de la botanique, the term alpha taxonomy is primarily used today to refer to the discipline of finding, describing, and naming taxa, particularly species. In earlier literature, the term had a different meaning, referring to morphological taxonomy, ideals can, it may be said, never be completely realized. They have, however, a value of acting as permanent stimulants. Some of us please ourselves by thinking we are now groping in a beta taxonomy, turrill thus explicitly excludes from alpha taxonomy various areas of study that he includes within taxonomy as a whole, such as ecology, physiology, genetics, and cytology. He further excludes phylogenetic reconstruction from alpha taxonomy, thus, Ernst Mayr in 1968 defined beta taxonomy as the classification of ranks higher than species. This activity is what the term denotes, it is also referred to as beta taxonomy. How species should be defined in a group of organisms gives rise to practical and theoretical problems that are referred to as the species problem. The scientific work of deciding how to define species has been called microtaxonomy, by extension, macrotaxonomy is the study of groups at higher taxonomic ranks, from subgenus and above only, than species. While some descriptions of taxonomic history attempt to date taxonomy to ancient civilizations, earlier works were primarily descriptive, and focused on plants that were useful in agriculture or medicine. There are a number of stages in scientific thinking. Early taxonomy was based on criteria, the so-called artificial systems. Later came systems based on a complete consideration of the characteristics of taxa, referred to as natural systems, such as those of de Jussieu, de Candolle and Bentham. The publication of Charles Darwins Origin of Species led to new ways of thinking about classification based on evolutionary relationships and this was the concept of phyletic systems, from 1883 onwards. This approach was typified by those of Eichler and Engler, the advent of molecular genetics and statistical methodology allowed the creation of the modern era of phylogenetic systems based on cladistics, rather than morphology alone. Taxonomy has been called the worlds oldest profession, and naming and classifying our surroundings has likely been taking place as long as mankind has been able to communicate
Taxonomy (biology)
–
Title page of
Systema Naturae, Leiden, 1735
Taxonomy (biology)
–
Evolution of the
vertebrates at class level, width of spindles indicating number of families. Spindle diagrams are typical for
Evolutionary taxonomy
Taxonomy (biology)
–
The same relationship, expressed as a
cladogram typical for
cladistics
Taxonomy (biology)
–
Type specimen for
Nepenthes smilesii, a tropical
pitcher plant.
2.
Animal
–
Animals are multicellular, eukaryotic organisms of the kingdom Animalia. The animal kingdom emerged as a clade within Apoikozoa as the group to the choanoflagellates. Animals are motile, meaning they can move spontaneously and independently at some point in their lives and their body plan eventually becomes fixed as they develop, although some undergo a process of metamorphosis later in their lives. All animals are heterotrophs, they must ingest other organisms or their products for sustenance, most known animal phyla appeared in the fossil record as marine species during the Cambrian explosion, about 542 million years ago. Animals can be divided broadly into vertebrates and invertebrates, vertebrates have a backbone or spine, and amount to less than five percent of all described animal species. They include fish, amphibians, reptiles, birds and mammals, the remaining animals are the invertebrates, which lack a backbone. These include molluscs, arthropods, annelids, nematodes, flatworms, cnidarians, ctenophores, the study of animals is called zoology. The word animal comes from the Latin animalis, meaning having breath, the biological definition of the word refers to all members of the kingdom Animalia, encompassing creatures as diverse as sponges, jellyfish, insects, and humans. Aristotle divided the world between animals and plants, and this was followed by Carl Linnaeus, in the first hierarchical classification. In Linnaeuss original scheme, the animals were one of three kingdoms, divided into the classes of Vermes, Insecta, Pisces, Amphibia, Aves, and Mammalia. Since then the last four have all been subsumed into a single phylum, in 1874, Ernst Haeckel divided the animal kingdom into two subkingdoms, Metazoa and Protozoa. The protozoa were later moved to the kingdom Protista, leaving only the metazoa, thus Metazoa is now considered a synonym of Animalia. Animals have several characteristics that set apart from other living things. Animals are eukaryotic and multicellular, which separates them from bacteria and they are heterotrophic, generally digesting food in an internal chamber, which separates them from plants and algae. They are also distinguished from plants, algae, and fungi by lacking cell walls. All animals are motile, if only at life stages. In most animals, embryos pass through a stage, which is a characteristic exclusive to animals. With a few exceptions, most notably the sponges and Placozoa and these include muscles, which are able to contract and control locomotion, and nerve tissues, which send and process signals
Animal
–
Carl Linnaeus, known as the father of modern
taxonomy
Animal
–
Had'n
Animal
–
The use of
love darts by the land snail
Monachoides vicinus is a form of
sexual selection
Animal
–
A
newt lung cell stained with
fluorescent dyes undergoing the early
anaphase stage of
mitosis
3.
Insect
–
Insects are a class of hexapod invertebrates within the arthropod phylum that have a chitinous exoskeleton, a three-part body, three pairs of jointed legs, compound eyes and one pair of antennae. They are the most diverse group of animals on the planet, including more than a million described species, the number of extant species is estimated at between six and ten million, and potentially represent over 90% of the differing animal life forms on Earth. Insects may be found in all environments, although only a small number of species reside in the oceans. The life cycles of insects vary but most hatch from eggs, insect growth is constrained by the inelastic exoskeleton and development involves a series of molts. The immature stages can differ from the adults in structure, habit and habitat, Insects that undergo 3-stage metamorphosis lack a pupal stage and adults develop through a series of nymphal stages. The higher level relationship of the Hexapoda is unclear, fossilized insects of enormous size have been found from the Paleozoic Era, including giant dragonflies with wingspans of 55 to 70 cm. The most diverse insect groups appear to have coevolved with flowering plants, adult insects typically move about by walking, flying or sometimes swimming. As it allows for rapid yet stable movement, many insects adopt a tripedal gait in which they walk with their legs touching the ground in alternating triangles, Insects are the only invertebrates to have evolved flight. Many insects spend at least part of their lives under water, with adaptations that include gills. Some species, such as water striders, are capable of walking on the surface of water, Insects are mostly solitary, but some, such as certain bees, ants and termites, are social and live in large, well-organized colonies. Some insects, such as earwigs, show maternal care, guarding their eggs, Insects can communicate with each other in a variety of ways. Male moths can sense the pheromones of female moths over great distances, other species communicate with sounds, crickets stridulate, or rub their wings together, to attract a mate and repel other males. Lampyridae in the beetle order communicate with light, humans regard certain insects as pests, and attempt to control them using insecticides and a host of other techniques. Some insects damage crops by feeding on sap, leaves or fruits, a few parasitic species are pathogenic. Some insects perform complex ecological roles, blow-flies, for example, help consume carrion, Many other insects are considered ecologically beneficial as predators and a few provide direct economic benefit. Silkworms and bees have been used extensively by humans for the production of silk and honey, in some cultures, people eat the larvae or adults of certain insects. Insect first appears documented in English in 1601 in Hollands translation of Pliny, translations of Aristotles term also form the usual word for insect in Welsh, Serbo-Croatian, Russian, etc. The evolutionary relationship of insects to other animal groups remains unclear, in the Pancrustacea theory, insects, together with Entognatha, Remipedia, and Cephalocarida, make up a natural clade labeled Miracrustacea
Insect
Insect
–
Evolution has produced enormous variety in insects. Pictured are some of the possible shapes of
antennae.
Insect
–
The different forms of the male (top) and female (bottom)
tussock moth Orgyia recens is an example of
sexual dimorphism in insects.
4.
Lepidoptera
–
The Lepidoptera is an order of insects that includes moths and butterflies. 180,000 species of Lepidoptera are described, in 126 families and 46 superfamilies and it is one of the most widespread and widely recognizable insect orders in the world. The term was coined by Linnaeus in 1735 and is derived from Ancient Greek λεπίδος, the Lepidoptera show many variations of the basic body structure that have evolved to gain advantages in lifestyle and distribution. Recent estimates suggest the order may have more species than earlier thought, and is among the four most speciose orders, along with the Hymenoptera, Diptera, and Coleoptera. Lepidopteran species are characterized by more than three derived features, some of the most apparent being the scales covering their bodies and wings, the scales are modified, flattened hairs, and give butterflies and moths their extraordinary variety of colors and patterns. Almost all species have some form of wings, except for a few that have reduced wings or are wingless. Like most other insects, butterflies and moths are holometabolous, meaning they undergo complete metamorphosis, mating and the laying of eggs are carried out by adults, normally near or on host plants for the larvae. As they grow, these change in appearance, going through a series of stages called instars. Once fully matured, the larva develops into a pupa A few butterflies and many species spin a silk case or cocoon prior to pupating, while others do not. A butterfly pupa, called a chrysalis, has a hard skin, once the pupa has completed its metamorphosis, a sexually mature adult emerges. Accordingly, this is the most recognized and popular of insect orders with many involved in the observation, study, collection, rearing of. A person who collects or studies this order is referred to as a lepidopterist, in many species, the female may produce from 200 to 600 eggs, while in others, the number may approach 30,000 eggs in one day. The caterpillars hatching from eggs can cause damage to large quantities of crops. Many moth and butterfly species are of economic interest by virtue of their role as pollinators, the word Lepidoptera comes from the Latin word for scaly wing, from the Ancient Greek λεπίς meaning scale and πτερόν meaning wing. The origins of the common names butterfly and moth are varied, the English word butterfly is from Old English buttorfleoge, with many variations in spelling. Other than that, the origin is unknown, although it could be derived from the yellow color of many species wings suggesting the color of butter. The species of Heterocera are commonly called moths, the origins of the English word moth are more clear, deriving from the Old English moððe from Common Germanic. The Lepidoptera are among the most successful groups of insects, among the most northern dwelling species of butterflies and moths is the Arctic Apollo, which is found in the Arctic Circle in northeastern Yakutia, at an altitude of 1500 m above sea level
Lepidoptera
Lepidoptera
–
The face of a caterpillar with the mouthparts showing
Lepidoptera
–
Caterpillar prolegs on
Papilio machaon
Lepidoptera
–
Wing scales form the color and pattern on wings. The scales shown here are lamellar. The pedicel can be seen attached to a few loose scales.
5.
Saturniidae
–
The family Saturniidae, commonly known as saturniids, by most measures include the largest species of moths. They are a family of Lepidoptera, with an estimated 2,300 described species worldwide, the Saturniidae include such Lepidoptera as the giant silkmoths, royal moths and emperor moths. Adults are characterized by size, heavy bodies covered in hair-like scales, lobed wings, reduced mouthparts. They lack a frenulum but the wings overlap the forewings. These moths are brightly colored and often have translucent eyespots or windows on their wings. Sexual dimorphism varies by species, but males can generally be distinguished by their larger, broader antennae, most adults possess wing spans between 1 and 6 in, but some tropical species, such as the Atlas moth, may have wing spans up to 12 in. Together with certain Noctuidae, the Saturniidae contain the largest Lepidoptera, the majority of saturniid species occur in wooded tropical or subtropical regions, with the greatest diversity in the New World tropics and Mexico, though they are found all over the world. Some saturniids are strictly univoltine, producing one generation a year, whereas others are multivoltine. Spring and summer broods hatch in a matter of weeks, autumn broods enter a state known as diapause, longer days may prompt pupae to develop early, while shorter days result in pupal diapause. In some species – e. g. the luna moth or Callosamia securifera –, spring and summer broods look different, depending on the moth, a single female may lay up to 200 eggs on a chosen host plant. Others are laid singly or in small groups and they are round, slightly flattened, smooth and translucent or whitish. Saturniid caterpillars are large, stout, and cylindrical, most have tubercules that are often also spiny or hairy. Many are cryptic in coloration, with countershading or disruptive coloration to reduce detection, a few species have been noted to produce clicking sounds with the larval mandibles when disturbed. The clicks may serve as warning signals to a regurgitation defense. Most are solitary feeders, but some are gregarious, the Hemileucinae are gregarious when young and have stinging hairs, those of Lonomia containing a poison which may kill a human. A. armida is another example, and are infamous for their large conspicuous masses during the day. Their coloration is not cryptic, instead exhibiting aposematism, the other caterpillars in this size range are almost universally Sphingidae, which are seldom hairy and tend to have diagonal stripes on their sides. Many Sphingidae caterpillars bear a single curved horn on their hind end and these are actually not dangerous, but large-haired caterpillars should generally not be touched except by experts
Saturniidae
–
Saturniids
Saturniidae
–
Marbled emperor moth (
Heniocha dyops) in
Botswana
Saturniidae
–
Life stages of giant emperor moth (
Saturnia pyri)
Saturniidae
–
Clutch of emperor gum moth (
Opodiphthera eucalypti) eggs
6.
Antheraea
–
Antheraea is a moth genus belonging to the family Saturniidae. Several species of this genus have caterpillars which produce wild silk of commercial importance, commonly called tussar silk, the moths are named tussar moths after the fabric. The wild silk moths of North America, ISBN 0-8014-3130-1 Studies on the filament of tasar silkworm, Antheraea mylitta D. G. Shamitha and A. Purushotham Rao. 12,25 JUNE2006, pp. 1667–1671, PDF file downloadable from, Raw & Organic Silk, Facts behind the Fibers Walter Sweadner and the Wild Silk Moths of the Bitteroot Mountains. Downloadable pdf file on Antheraea yamamai ANTHERAEA Hübner,1816
Antheraea
–
Tussah moths
7.
Binomial nomenclature
–
Such a name is called a binomial name, a binomen, binominal name or a scientific name, more informally it is also called a Latin name. The first part of the name identifies the genus to which the species belongs, for example, humans belong to the genus Homo and within this genus to the species Homo sapiens. The formal introduction of system of naming species is credited to Carl Linnaeus. But Gaspard Bauhin, in as early as 1623, had introduced in his book Pinax theatri botanici many names of genera that were adopted by Linnaeus. Although the general principles underlying binomial nomenclature are common to these two codes, there are differences, both in the terminology they use and in their precise rules. Similarly, both parts are italicized when a binomial name occurs in normal text, thus the binomial name of the annual phlox is now written as Phlox drummondii. In scientific works, the authority for a name is usually given, at least when it is first mentioned. In zoology Patella vulgata Linnaeus,1758, the original name given by Linnaeus was Fringilla domestica, the parentheses indicate that the species is now considered to belong in a different genus. The ICZN does not require that the name of the person who changed the genus be given, nor the date on which the change was made, in botany Amaranthus retroflexus L. – L. is the standard abbreviation used in botany for Linnaeus. – Linnaeus first named this bluebell species Scilla italica, Rothmaler transferred it to the genus Hyacinthoides, the ICN does not require that the dates of either publication be specified. Prior to the adoption of the binomial system of naming species. Together they formed a system of polynomial nomenclature and these names had two separate functions. First, to designate or label the species, and second, to be a diagnosis or description, such polynomial names may sometimes look like binomials, but are significantly different. For example, Gerards herbal describes various kinds of spiderwort, The first is called Phalangium ramosum, Branched Spiderwort, is aptly termed Phalangium Ephemerum Virginianum, Soon-Fading Spiderwort of Virginia. The Latin phrases are short descriptions, rather than identifying labels, the Bauhins, in particular Caspar Bauhin, took some important steps towards the binomial system, by pruning the Latin descriptions, in many cases to two words. The adoption by biologists of a system of binomial nomenclature is due to Swedish botanist and physician Carl von Linné. It was in his 1753 Species Plantarum that he first began using a one-word trivial name together with a generic name in a system of binomial nomenclature. This trivial name is what is now known as an epithet or specific name
Binomial nomenclature
–
Carl Linnaeus (1707–1778), a Swedish botanist, invented the modern system of binomial nomenclature.
8.
Synonym (taxonomy)
–
For example, Linnaeus was the first to give a scientific name 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 which is 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. 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 a name that is one taxonomists synonym may be another taxonomists correct name. 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 one, a species is moved to a different genus. To the general user of scientific names, in such as agriculture, horticulture, ecology, general science. A synonym is a name that was used as the correct scientific name but which has been displaced by another scientific name. Thus Oxford Dictionaries Online defines the term as a name which has the same application as another. In handbooks and general texts, it is useful to have mentioned as such after the current scientific name. Synonyms used in this way may not always meet the strict definitions of the synonym in the formal rules of nomenclature which govern scientific names. Changes of scientific name have two causes, they may be taxonomic or nomenclatural, a name change may be caused by changes in the circumscription, position or rank of a taxon, representing a change in taxonomic, scientific insight. A name change may be due to purely nomenclatural reasons, that is, based on the rules of nomenclature, the earliest such name is called the senior synonym, while the later name is the junior synonym. One basic principle of zoological nomenclature is that the earliest correctly published name, synonyms are important because if the earliest name cannot be used, then the next available junior synonym must be used for the taxon. Objective synonyms refer to taxa with the type and same rank. For example, John Edward Gray published the name Antilocapra anteflexa in 1855 for a species of pronghorn, however, it is now commonly accepted that his specimen was an unusual individual of the species Antilocapra americana published by George Ord in 1815. Ords name thus takes precedence, with Antilocapra anteflexa being a subjective synonym. Objective synonyms are common at the level of genera, because for various reasons two genera may contain the type species, these are objective synonyms
Synonym (taxonomy)
–
The
Latin Caudata and
Greek Urodela both mean "tailed" and have been used as a scientific name at the rank of order for the
salamanders (as opposed to the tail-less
frogs). Thus they are synonyms.
Synonym (taxonomy)
–
The common dandelion
Taraxacum officinale sensu lato is an extremely widespread group of
apomictic lineages, and some scientists apply the "biological species concept" to divide it into many distinct species; other scientists regard all the names for those independent species as synonyms.
9.
Moth
–
Moths comprise a group of insects related to butterflies, belonging to the order Lepidoptera. Most lepidopterans are moths, and there are thought to be approximately 160,000 species of moth, most species of moth are nocturnal, but there are also crepuscular and diurnal species. While the butterflies form a group, the moths, comprising the rest of the Lepidoptera. Moth antennae can be varied in appearance, but in particular lack the club end. The divisions are named by this principle, club-antennae or varied-antennae, the modern English word moth comes from Old English moððe from Common Germanic. Moth larvae, or caterpillars, make cocoons from which emerge as fully grown moths with wings. Some moth caterpillars dig holes in the ground, where they live until they are ready to turn into adult moths, moths evolved long before butterflies, fossils having been found that may be 190 million years old. Both types of lepidoptera are thought to have evolved along with flowering plants, mainly because most modern species feed on flowering plants, one of the earliest species thought to be a moth-ancestor is Archaeolepis mane, whose fossil fragments show scaled wings similar to caddisflies in their veining. Some moths, particularly their caterpillars, can be agricultural pests in many parts of the world. Examples include corn borers and bollworms, the caterpillar of the gypsy moth causes severe damage to forests in the northeastern United States, where it is an invasive species. In temperate climates, the codling moth causes extensive damage, especially to fruit farms, in tropical and subtropical climates, the diamondback moth is perhaps the most serious pest of brassicaceous crops. Several moths in the family Tineidae are commonly regarded as pests because their larvae eat fabric such as clothes and they are less likely to eat mixed materials containing some artificial fibers. There are some reports that they may be repelled by the scent of wood from juniper and cedar, by lavender, or by natural oils, however. Naphthalene is considered effective, but there are concerns over its effects on human health. Moth larvae may be killed by freezing the items which they infest for several days at a temperature below −8 °C, despite being notorious for eating clothing, most moth adults do not eat at all. Many, like the Luna, Polyphemus, Atlas, Promethea, cecropia, among those adult moths that do eat, they will drink nectar. Some moths are farmed for their economic value, the most notable of these is the silkworm, the larva of the domesticated moth Bombyx mori. It is farmed for the silk with which it builds its cocoon, as of 2002, the silk industry produces more than 130 million kilograms of raw silk, worth about 250 million U. S. dollars, each year
Moth
–
Moth
Moth
–
Poplar hawk-moth caterpillar
Laothoe populi.
Moth
–
An adult male pine processionary moth (
Thaumetopoea pityocampa). This species is a serious forest pest when in larval state. Notice the bristle springing from the underside of the hindwing (
frenulum) and running forward to be held in a small catch of the forewing, whose function is to link the wings together.
Moth
–
Tomato Hornworm parasitized by
braconid wasps
10.
Family (biology)
–
In biological classification, family is one of the eight major taxonomic ranks, it is classified between order and genus. A family may be divided into subfamilies, which are intermediate ranks above the rank of genus. In vernacular usage, a family may be named one of its common members, for example, walnuts and hickory trees belong to the family Juglandaceae. What does or does not belong to a family—or whether a family should be recognized at all—are proposed and determined by practicing taxonomists. There are no rules for describing or recognizing a family. Taxonomists often take different positions about descriptions of taxa, and there may be no broad consensus across the community for some time. Some described taxa are accepted broadly and quickly, but others only rarely, if at all, the naming of families is codified by various international codes. In zoological nomenclature, the names of animals end with the suffix -idae. The concept of rank at time was not yet settled, and in the preface to the Prodromus Magnol spoke of uniting his families into larger genera. Carolus Linnaeus used the word familia in his Philosophia botanica to denote groups of plants, trees, herbs, ferns, palms. He used this term only in the section of the book. In zoology, the family as an intermediate between order and genus was introduced by Pierre André Latreille in his Précis des caractères génériques des insectes. He used families in some but not in all his orders of insects, families can be used for evolutionary, palaeontological and generic studies because they are more stable than lower taxonomic levels such as genera and species
Family (biology)
–
The hierarchy of
biological classification 's eight major
taxonomic ranks. An
order contains one or more families. Intermediate minor rankings are not shown.
11.
Evolution
–
Evolution is change in the heritable characteristics of biological populations over successive generations. Evolutionary processes give rise to biodiversity at every level of organisation, including the levels of species, individual organisms. In July 2016, scientists reported identifying a set of 355 genes from the LUCA of all living on Earth. The fossil record includes a progression from early biogenic graphite, to microbial mat fossils, existing patterns of biodiversity have been shaped both by speciation and by extinction. More than 99 percent of all species that lived on Earth are estimated to be extinct. Estimates of Earths current species range from 10 to 14 million, more recently, in May 2016, scientists reported that 1 trillion species are estimated to be on Earth currently with only one-thousandth of one percent described. In the mid-19th century, Charles Darwin formulated the theory of evolution by natural selection. This teleonomy is the quality whereby the process of natural selection creates and preserves traits that are fitted for the functional roles they perform. The processes by which the changes occur, from one generation to another, are called evolutionary processes or mechanisms, the four most widely recognized evolutionary processes are natural selection, genetic drift, mutation and gene migration. Natural selection and genetic drift sort variation, mutation and gene migration create variation, consequences of selection can include meiotic drive, nonrandom mating and genetic hitchhiking. In the early 20th century the modern evolutionary synthesis integrated classical genetics with Darwins theory of evolution by natural selection through the discipline of population genetics, the importance of natural selection as a cause of evolution was accepted into other branches of biology. Moreover, previously held notions about evolution, such as orthogenesis, evolutionism, evolutionary computation, a sub-field of artificial intelligence, involves the application of Darwinian principles to problems in computer science. The proposal that one type of organism could descend from another type goes back to some of the first pre-Socratic Greek philosophers, such as Anaximander, such proposals survived into Roman times. The poet and philosopher Lucretius followed Empedocles in his masterwork De rerum natura, in contrast to these materialistic views, Aristotelianism considered all natural things as actualisations of fixed natural possibilities, known as forms. This was part of a teleological understanding of nature in which all things have an intended role to play in a divine cosmic order. In the 17th century, the new method of modern science rejected the Aristotelian approach, however, this new approach was slow to take root in the biological sciences, the last bastion of the concept of fixed natural types. The biological classification introduced by Carl Linnaeus in 1735 explicitly recognized the nature of species relationships. Other naturalists of this time speculated on the change of species over time according to natural laws
Evolution
–
Lucretius
Evolution
Evolution
–
Alfred Russel Wallace
Evolution
–
Thomas Robert Malthus
12.
Chromosome rearrangement
–
In genetics, a chromosome translocation is a chromosome abnormality caused by rearrangement of parts between nonhomologous chromosomes. A gene fusion may be created when the translocation joins two otherwise-separated genes, it is detected on cytogenetics or a karyotype of affected cells, translocations can be balanced or unbalanced. Translocations can be reciprocal or nonreciprocal, reciprocal translocations are usually an exchange of material between nonhomologous chromosomes. Estimates of incidence range from about 1 in 500 to 1 in 625 human newborns, such translocations are usually harmless and may be found through prenatal diagnosis. However, carriers of balanced reciprocal translocations have increased risks of creating gametes with unbalanced chromosome translocations, genetic counseling and genetic testing are often offered to families that may carry a translocation. Most balanced translocation carriers are healthy and do not have any symptoms, but about 6% of them have a range of symptoms that may include autism, intellectual disability, or congenital anomalies. A gene disrupted or disregulated at the breakpoint of the carrier is likely the cause of these symptoms. The former results in a chromosomal abnormality featured in all cells of the offspring, somatic translocations, on the other hand, result in abnormalities featured only in the affected cell line, as in chronic myelogenous leukemia with the Philadelphia chromosome translocation. Robertsonian translocation is a type of translocation caused by breaks at or near the centromeres of two acrocentric chromosomes, the resulting karyotype in humans leaves only 45 chromosomes, since two chromosomes have fused together. This has no effect on the phenotype, since the only genes on the short arms of acrocentrics are common to all of them and are present in variable copy number. Robertsonian translocations have been seen involving all combinations of acrocentric chromosomes, the most common translocation in humans involves chromosomes 13 and 14 and is seen in about 0.97 /1000 newborns. Carriers of Robertsonian translocations are not associated with any phenotypic abnormalities, for example, carriers of Robertsonian translocations involving chromosome 21 have a higher chance of having a child with Down syndrome. This is known as a translocation Downs and this is due to a mis-segregation during gametogenesis. The mother has a risk of transmission than the father. Robertsonian translocations involving chromosome 14 also carry a risk of uniparental disomy 14 due to trisomy rescue. Some human diseases caused by translocations are, Cancer, Several forms of cancer are caused by acquired translocations, translocations have also been described in solid malignancies such as Ewings sarcoma. Infertility, One of the parents carries a balanced translocation. Down syndrome is caused in a minority of cases by a Robertsonian translocation of the chromosome 21 long arm onto the arm of chromosome 14
Chromosome rearrangement
–
Chromosomal reciprocal translocation of the 4th and 20th
chromosome.
13.
China
–
China, officially the Peoples Republic of China, is a unitary sovereign state in East Asia and the worlds most populous country, with a population of over 1.381 billion. The state is governed by the Communist Party of China and its capital is Beijing, the countrys major urban areas include Shanghai, Guangzhou, Beijing, Chongqing, Shenzhen, Tianjin and Hong Kong. China is a power and a major regional power within Asia. Chinas landscape is vast and diverse, ranging from forest steppes, the Himalaya, Karakoram, Pamir and Tian Shan mountain ranges separate China from much of South and Central Asia. The Yangtze and Yellow Rivers, the third and sixth longest in the world, respectively, Chinas coastline along the Pacific Ocean is 14,500 kilometers long and is bounded by the Bohai, Yellow, East China and South China seas. China emerged as one of the worlds earliest civilizations in the basin of the Yellow River in the North China Plain. For millennia, Chinas political system was based on hereditary monarchies known as dynasties, in 1912, the Republic of China replaced the last dynasty and ruled the Chinese mainland until 1949, when it was defeated by the communist Peoples Liberation Army in the Chinese Civil War. The Communist Party established the Peoples Republic of China in Beijing on 1 October 1949, both the ROC and PRC continue to claim to be the legitimate government of all China, though the latter has more recognition in the world and controls more territory. China had the largest economy in the world for much of the last two years, during which it has seen cycles of prosperity and decline. Since the introduction of reforms in 1978, China has become one of the worlds fastest-growing major economies. As of 2016, it is the worlds second-largest economy by nominal GDP, China is also the worlds largest exporter and second-largest importer of goods. China is a nuclear weapons state and has the worlds largest standing army. The PRC is a member of the United Nations, as it replaced the ROC as a permanent member of the U. N. Security Council in 1971. China is also a member of numerous formal and informal multilateral organizations, including the WTO, APEC, BRICS, the Shanghai Cooperation Organization, the BCIM, the English name China is first attested in Richard Edens 1555 translation of the 1516 journal of the Portuguese explorer Duarte Barbosa. The demonym, that is, the name for the people, Portuguese China is thought to derive from Persian Chīn, and perhaps ultimately from Sanskrit Cīna. Cīna was first used in early Hindu scripture, including the Mahābhārata, there are, however, other suggestions for the derivation of China. The official name of the state is the Peoples Republic of China. The shorter form is China Zhōngguó, from zhōng and guó and it was then applied to the area around Luoyi during the Eastern Zhou and then to Chinas Central Plain before being used as an occasional synonym for the state under the Qing
China
–
Yinxu, ruins of an ancient
palace dating from the
Shang Dynasty (14th century BCE)
China
–
Flag
China
–
Some of the thousands of life-size
Terracotta Warriors of the
Qin Dynasty, c. 210 BCE
China
–
The
Great Wall of China was built by several dynasties over two thousand years to protect the sedentary agricultural regions of the
Chinese interior from incursions by
nomadic pastoralists of the northern
steppes.
14.
Asia
–
Asia covers an area of 44,579,000 square kilometres, about 30% of Earths total land area and 8. 7% of the Earths total surface area. The continent, which has long been home to the majority of the population, was the site of many of the first civilizations. Asia is notable for not only its large size and population. In general terms, Asia is bounded on the east by the Pacific Ocean, on the south by the Indian Ocean, the western boundary with Europe is a historical and cultural construct, as there is no clear physical and geographical separation between them. The most commonly accepted boundaries place Asia to the east of the Suez Canal, the Ural River, and the Ural Mountains, and south of the Caucasus Mountains, China and India alternated in being the largest economies in the world from 1 to 1800 A. D. The accidental discovery of America by Columbus in search for India demonstrates this deep fascination, the Silk Road became the main East-West trading route in the Asian hitherland while the Straits of Malacca stood as a major sea route. Asia has exhibited economic dynamism as well as robust population growth during the 20th century, given its size and diversity, the concept of Asia—a name dating back to classical antiquity—may actually have more to do with human geography than physical geography. Asia varies greatly across and within its regions with regard to ethnic groups, cultures, environments, economics, historical ties, the boundary between Asia and Africa is the Red Sea, the Gulf of Suez, and the Suez Canal. This makes Egypt a transcontinental country, with the Sinai peninsula in Asia, the border between Asia and Europe was historically defined by European academics. In Sweden, five years after Peters death, in 1730 Philip Johan von Strahlenberg published a new atlas proposing the Urals as the border of Asia, the Russians were enthusiastic about the concept, which allowed them to keep their European identity in geography. Tatishchev announced that he had proposed the idea to von Strahlenberg, the latter had suggested the Emba River as the lower boundary. Over the next century various proposals were made until the Ural River prevailed in the mid-19th century, the border had been moved perforce from the Black Sea to the Caspian Sea into which the Ural River projects. The border between the Black Sea and the Caspian is usually placed along the crest of the Caucasus Mountains, the border between Asia and the loosely defined region of Oceania is usually placed somewhere in the Malay Archipelago. The terms Southeast Asia and Oceania, devised in the 19th century, have had several different geographic meanings since their inception. The chief factor in determining which islands of the Malay Archipelago are Asian has been the location of the possessions of the various empires there. Lewis and Wigen assert, The narrowing of Southeast Asia to its present boundaries was thus a gradual process, Asia is larger and more culturally diverse than Europe. It does not exactly correspond to the borders of its various types of constituents. From the time of Herodotus a minority of geographers have rejected the three-continent system on the grounds there is no or is no substantial physical separation between them
Asia
–
Two-point equidistant projection of Asia and surrounding landmasses.
Asia
–
Asia
Asia
–
The racial diversity of Asia's peoples,
Nordisk familjebok (1904)
Asia
–
Ptolemy's Asia
15.
Bombyx mori
–
The silkworm is the larva or caterpillar of the domesticated silk moth, Bombyx mori. It is an important insect, being a primary producer of silk. A silkworms preferred food is white mulberry leaves, though they may eat other mulberry species, domestic silk moths are closely dependent on humans for reproduction, as a result of millennia of selective breeding. Wild silk moths are different from their cousins, they are not as commercially viable in the production of silk. The silkworm was domesticated from the wild silkmoth Bombyx mandarina, which has a range from northern India to northern China, Korea, Japan, the domesticated silkworm derives from Chinese rather than Japanese or Korean stock. Silkworms were unlikely to have been domestically bred before the Neolithic age, before then, the tools to manufacture quantities of silk thread had not been developed. The domesticated B. mori and the wild B. mandarina can still breed, mulberry silkworms can be categorized into three different but connected groups or types. The major groups of silkworms fall under the univoltine and bivoltine categories, the univoltine breed is generally linked with the geographical area within greater Europe. The eggs of this type hibernate during winter due to the cold climate, the second type is called bivoltine and is normally found in China, Japan, and Korea. The breeding process of this takes place twice annually, a feat made possible through the slightly warmer climates. The polyvoltine type of mulberry silkworm can only be found in the tropics, the eggs are laid by female moths and hatch within nine to 12 days, so the resulting type can have up to eight separate life cycles throughout the year. Eggs take about 14 days to hatch into larvae, which eat continuously and they have a preference for white mulberry, having an attraction to the mulberry odorant cis-jasmone. They are not monophagous since they can eat other species of Morus, as well as some other Moraceae and they are covered with tiny black hairs. When the color of their heads turns darker, it indicates they are about to molt, after molting, the instar phase of the silkworms emerge white, naked, and with little horns on their backs. After they have molted four times, their bodies become slightly yellow, the larvae then prepare to enter the pupal phase of their lifecycle, and enclose themselves in a cocoon made up of raw silk produced by the salivary glands. The final molt from larva to pupa takes place within the cocoon, to prevent this, silkworm cocoons are boiled. The heat kills the silkworms and the water makes the cocoons easier to unravel, often, the silkworm itself is eaten. As the process of harvesting the silk from the cocoon kills the larvae, sericulture has been criticized by animal welfare, mahatma Gandhi was critical of silk production based on the Ahimsa philosophy not to hurt any living thing
Bombyx mori
–
Bombyx mori
Bombyx mori
Bombyx mori
–
Adult silkworm moth
Bombyx mori
–
Wild silkmoth
Bombyx mandarina
16.
Han Dynasty
–
The Han dynasty was the second imperial dynasty of China, preceded by the Qin dynasty and succeeded by the Three Kingdoms period. Spanning over four centuries, the Han period is considered an age in Chinese history. To this day, Chinas majority ethnic group refers to itself as the Han people and it was founded by the rebel leader Liu Bang, known posthumously as Emperor Gaozu of Han, and briefly interrupted by the Xin dynasty of the former regent Wang Mang. This interregnum separates the Han dynasty into two periods, the Western Han or Former Han and the Eastern Han or Later Han, the emperor was at the pinnacle of Han society. He presided over the Han government but shared power with both the nobility and appointed ministers who came largely from the gentry class. The Han Empire was divided into areas controlled by the central government using an innovation inherited from the Qin known as commanderies. These kingdoms gradually lost all vestiges of their independence, particularly following the Rebellion of the Seven States, from the reign of Emperor Wu onward, the Chinese court officially sponsored Confucianism in education and court politics, synthesized with the cosmology of later scholars such as Dong Zhongshu. This policy endured until the fall of the Qing dynasty in 1911 AD, the Han dynasty was an age of economic prosperity and saw a significant growth of the money economy first established during the Zhou dynasty. The coinage issued by the government mint in 119 BC remained the standard coinage of China until the Tang dynasty. The period saw a number of limited institutional innovations, the Xiongnu, a nomadic steppe confederation, defeated the Han in 200 BC and forced the Han to submit as a de facto inferior partner, but continued their raids on the Han borders. Emperor Wu of Han launched several campaigns against them. The ultimate Han victory in these wars eventually forced the Xiongnu to accept vassal status as Han tributaries, the territories north of Hans borders were quickly overrun by the nomadic Xianbei confederation. Imperial authority was seriously challenged by large Daoist religious societies which instigated the Yellow Turban Rebellion. When Cao Pi, King of Wei, usurped the throne from Emperor Xian, following Liu Bangs victory in the Chu–Han Contention, the resulting Han dynasty was named after the Hanzhong fief. Chinas first imperial dynasty was the Qin dynasty, the Qin unified the Chinese Warring States by conquest, but their empire became unstable after the death of the first emperor Qin Shi Huangdi. Within four years, the authority had collapsed in the face of rebellion. Although Xiang Yu proved to be a commander, Liu Bang defeated him at Battle of Gaixia. Liu Bang assumed the title emperor at the urging of his followers and is known posthumously as Emperor Gaozu, Changan was chosen as the new capital of the reunified empire under Han
Han Dynasty
–
History of China
Han Dynasty
–
Han dynasty in 1 AD.
Han Dynasty
–
A
silk banner from
Mawangdui,
Changsha,
Hunan province. It was draped over the coffin of
Lady Dai (d. 168 BC), wife of the Marquess Li Cang (利蒼) (d. 186 BC), chancellor for the Kingdom of Changsha.
Han Dynasty
–
A
gilded bronze
oil lamp in the shape of a kneeling female servant, dated 2nd century BC, found in the tomb of
Dou Wan, wife of the Han prince
Liu Sheng; its sliding shutter allows for adjustments in the direction and brightness in light while it also traps smoke within the body.
17.
Three Kingdoms
–
The Three Kingdoms was the tripartite division of China between the states of Wei, Shu, and Wu, following the Han dynasty and preceding the Jin dynasty. The term Three Kingdoms itself is something of a mistranslation, since each state was eventually headed not by a king, nevertheless, the term Three Kingdoms has become standard among sinologists. Academically, the period of the Three Kingdoms refers to the period between the foundation of the state of Wei in 220 AD and the conquest of the state of Wu by the Jin dynasty in 280. The earlier, unofficial part of the period, from 184 to 220, was marked by infighting between warlords in various parts of China. The middle part of the period, from 220 and 263, was marked by a more militarily stable arrangement between three states of Wei, Shu, and Wu. The later part of the era was marked by the conquest of Shu by Wei, the usurpation of Wei by the Jin dynasty, the Three Kingdoms period is one of the bloodiest in Chinese history. While the census may not have been particularly accurate due to a multitude of factors of the times, technology advanced significantly during this period. Shu chancellor Zhuge Liang invented the wooden ox, suggested to be a form of the wheelbarrow. Wei mechanical engineer Ma Jun is considered by many to be the equal of his predecessor Zhang Heng, although relatively short, this historical period has been greatly romanticized in the cultures of China, Japan, Korea, and Vietnam. It has been celebrated and popularized in operas, folk stories, novels and in recent times, films, television. The best known of these is Luo Guanzhongs Romance of the Three Kingdoms, the authoritative historical record of the era is Chen Shous Records of the Three Kingdoms, along with Pei Songzhis later annotations of the text. There is no set time period for the era, and many definitions are given. The strictest rule of dating would be to deem the era to be from the point where all three states coexisted as independent states up until the downfall of the Shu-Han states. Mao Zonggang, a commentator on the Romance of the Three Kingdoms, mentions in his commentary on Chapter 120 of the novel that, the Han royal house declined when the eunuchs abused the sovereign and officials subverted the government. In doing so, he suggests that the historiography of the Three Kingdoms should begin at the rise of the Ten Eunuchs to power. He further argues that the Romance of the Three Kingdoms defines the end of the era as 280, to end the tale before Hans enemy had itself met its fate would be to leave the reader unsatisfied. The novel could have ended with the fall of Wei, to end the tale before Hans ally had fallen would be to leave the reader with an incomplete picture. So the tale had to end with the fall of Wu, the power of the Eastern Han dynasty went into depression and steadily declined from a variety of political and economic problems after the death in 105 of Emperor He
Three Kingdoms
–
History of China
Three Kingdoms
–
A Chinese Three Kingdoms era decorated brick taken from the wall of an underground tomb, with miniature paintings depicting people in domestic scenes
Three Kingdoms
–
Map of Chinese provinces in the prelude of Three Kingdom period (In the late Han dynasty period, 189 AD).
18.
Hybrid (biology)
–
In biology, a hybrid, also known as a cross breed, is the result of combining, through sexual reproduction, the qualities of two animals or plants of different breeds, varieties, species or genera. Hybrids are not always intermediate between their parents, but can show heterosis or hybrid vigour, often growing larger or taller than either parent, some act before fertilization, others after it. A few animal species and many plant species, however, are the result of hybrid speciation, doubling the number of chromosomes to create polyploids is important in hybrid speciation, because homoploid hybrids are rarely fertile, the polyploid hybrids are allopolyploids. Human impact on the environment has greatly increased the mixing of species, with introduced species worldwide, the genetic mixing may threaten many species with extinction, while genetic erosion in crop plants may be damaging the gene pools of many species for future breeding. Many commercially useful fruits, flowers, garden herbs and trees have been produced by hybridization, one flower, Oenothera lamarckiana, was central to early genetics research into polyploidy. The term hybrid is derived from Latin hybrida, used for such as of a tame sow and a wild boar, or the child of a freeman. The term came into use in English in the 19th century. Conspicuous hybrids are named with portmanteau words, starting in the 1920s with the breeding of tiger-lion hybrids. The cross between two different homozygous lines produces an F1 hybrid that is heterozygous, having two alleles, one contributed by each parent and typically one is dominant and the other recessive. Typically, the F1 generation is also phenotypically homogeneous, producing offspring that are all similar to each other, double cross hybrids result from the cross between two different F1 hybrids. Three-way cross hybrids result from the cross between an F1 hybrid and an inbred line, triple cross hybrids result from the crossing of two different three-way cross hybrids. Top cross hybrids result from the crossing of a top quality or pure-bred male, population hybrids result from the crossing of plants or animals in a population with those of another population. These include interspecific hybrids or crosses between different breeds. e, from the point of view of genetics, different kinds of hybrid can be distinguished as follows, A genetic hybrid carries two different alleles of the same gene. A structural hybrid results from the fusion of gametes that have differing structure in at least one chromosome, a numerical hybrid results from the fusion of gametes having different haploid numbers of chromosomes. A permanent hybrid results when only the heterozygous genotype occurs, as in Oenothera lamarckiana, from the point of view of taxonomy, hybrids differ according to their parentage, Hybrids between different subspecies are called intra-specific hybrids. Offspring resulting from interspecies mating, are called interspecific hybrids, these result in hybrid speciation. Intergeneric hybrids result from matings between different genera, such as sheep and goats. Interfamilial hybrids such as chickens and guineafowl or pheasants are reliably described but extremely rare
Hybrid (biology)
–
Hercules, a "
liger ", a lion/tiger hybrid.
Hybrid (biology)
–
A "
zonkey ", a zebra/donkey hybrid.
Hybrid (biology)
–
A "
jaglion ", a jaguar/lion hybrid.
Hybrid (biology)
–
A
mule, a domestic canary/goldfinch hybrid.
19.
Backcross
–
It is used in horticulture, animal breeding and in production of gene knockout organisms. It is thought to have arisen from a backcrossing of the F1 hybrid with S. vulgaris, again, the pure tall and pure dwarf pea plants when crossed in the parental generation, they produce all heterozygote tall pea plants in the first filial generation. The cross between first filial heterozygote tall pea plant and pure tall or pure dwarf pea plant of the generation is also an example for the back-crossing between two plants. The former of these traits is called a test cross. Backcrossing may be employed in animals to transfer a desirable trait in an animal of inferior genetic background to an animal of preferable genetic background. A consomic strain is a strain with one of its chromosomes replaced by the homologous chromosome of another inbred strain via a series of marker-assisted backcrosses. Introgression The Plant Breeding and Genomics Community of Practice on eXtension - education and training materials for plant breeders and allied professionals
Backcross
–
This image demonstrates backcrossing of a heterozygous mouse from one genetic background onto another genetic background. In this example, the gene knockout is performed on 129/Sv cells and then backcrossed into the C57B/6J genetic background. With each successive backcross, there is an increase in the percentage of C57B/6J DNA that constitutes the genome of the offspring.
20.
Paternal mtDNA transmission
–
In genetics, paternal mtDNA transmission and paternal mtDNA inheritance refer to the incidence of mitochondrial DNA being passed from a father to his offspring. Paternal mtDNA inheritance is observed in a proportion of species, in general. In contrast, mtDNA transmission from both parents occurs regularly in certain bivalves, paternal mtDNA inheritance in animals varies. For example, in Mytilidae mussels, paternal mtDNA is transmitted through the sperm, in testing 172 sheep, The Mitochondrial DNA from three lambs in two half-sib families were found to show paternal inheritance. An instance of paternal leakage resulted in a study on chickens, there has been evidences that paternal leakage is an integral part of the inheritance of Drosophila simulans. In human mitochondrial genetics, there is debate whether or not paternal mtDNA transmission is possible. Many studies hold that paternal mtDNA is never transmitted to offspring and this thought is central to mtDNA genealogical DNA testing and to the theory of mitochondrial Eve. The fact that mitochondrial DNA is maternally inherited enables researchers to trace maternal lineage far back in time, in sexual reproduction, paternal mitochondria found in the sperm are actively decomposed, thus preventing paternal leakage. Mitochondria in mammalian sperm are usually destroyed by the egg cell after fertilization, in 1999 it was reported that paternal sperm mitochondria are marked with ubiquitin to select them for later destruction inside the embryo. Some in vitro techniques, particularly intracytoplasmic sperm injection of a sperm into an oocyte. It is now understood that the tail of the sperm, which contains additional mtDNA and this had led to increased controversy about the fate of paternal mtDNA. Some sources state that so little paternal mtDNA is transmitted as to be negligible or that paternal mtDNA is so rarely transmitted as to be negligible, one study stated that about 1–2% of a persons mitochondria can be inherited from the father. The controversy about human paternal leakage was summed up in the 1996 study Misconceptions about mitochondria and mammalian fertilization, however, there has been only a single documented case of human paternal mitochondrial DNA transmission. According to the 2005 study More evidence for non-maternal inheritance of mitochondrial DNA. heteroplasmy is a newly discovered form of inheritance for mtDNA, heteroplasmy introduces slight statistical uncertainty in normal inheritance patterns. Some organisms, such as Cryptosporidium, have mitochondria with no DNA whatsoever, in plants, it has also been reported that mitochondria can occasionally be inherited from the father, e. g. in bananas. Some Conifers also show paternal inheritance of mitochondria, such as the coast redwood, y-chromosomal Adam Patrilineality Matrilineality Human mitochondrial genetics Human migration RecLOH List of genetic genealogy topics Marchington DR, Scott Brown MS, Lamb VK, et al. No evidence for paternal mtDNA transmission to offspring or extra-embryonic tissues after ICSI, sigurğardóttir S, Helgason A, Gulcher JR, Stefansson K, Donnelly P. The mutation rate in the human mtDNA control region, zeviani M, Di Donato S. Mitochondrial disorders
Paternal mtDNA transmission
–
Mitochondrial Inheritance Patterns
21.
Mitochondrial genome
–
Mitochondrial DNA is the DNA located in mitochondria, cellular organelles within eukaryotic cells that convert chemical energy from food into a form that cells can use, adenosine triphosphate. Mitochondrial DNA is only a portion of the DNA in a eukaryotic cell, most of the DNA can be found in the cell nucleus and, in plants and algae. In humans, the 16,569 base pairs of mitochondrial DNA encode for only 37 genes, human mitochondrial DNA was the first significant part of the human genome to be sequenced. In most species, including humans, mtDNA is inherited solely from the mother, since animal mtDNA evolves faster than nuclear genetic markers, it represents a mainstay of phylogenetics and evolutionary biology. It also permits an examination of the relatedness of populations, and so has become important in anthropology and this theory is called the endosymbiotic theory. Each mitochondrion is estimated to contain 2–10 mtDNA copies, the reasons why mitochondria have retained some genes are debated. Recent analysis of a range of mtDNA genomes suggests that both these features may dictate mitochondrial gene retention. In most multicellular organisms, mtDNA is inherited from the mother, mechanisms for this include simple dilution, degradation of sperm mtDNA in the male genital tract, in the fertilized egg, and, at least in a few organisms, failure of sperm mtDNA to enter the egg. Whatever the mechanism, this single parent pattern of inheritance is found in most animals, most plants. In sexual reproduction, mitochondria are inherited exclusively from the mother. Also, most mitochondria are present at the base of the sperms tail, in 1999 it was reported that paternal sperm mitochondria are marked with ubiquitin to select them for later destruction inside the embryo. Some in vitro techniques, particularly injecting a sperm into an oocyte. The fact that mitochondrial DNA is maternally inherited enables researchers to trace maternal lineage far back in time. This is usually accomplished on human mitochondrial DNA by sequencing the hypervariable control regions, hVR1, for example, consists of about 440 base pairs. These 440 base pairs are then compared to the regions of other individuals to determine maternal lineage. Most often, the comparison is made to the revised Cambridge Reference Sequence, vilà et al. have published studies tracing the matrilineal descent of domestic dogs to wolves. The concept of the Mitochondrial Eve is based on the type of analysis. MtDNA is highly conserved, and its relatively slow mutation rates make it useful for studying the evolutionary relationships—phylogeny—of organisms, biologists can determine and then compare mtDNA sequences among different species and use the comparisons to build an evolutionary tree for the species examined
Mitochondrial genome
–
Electron microscopy reveals mitochondrial DNA in discrete foci. Bars: 200 nm. (A) Cytoplasmic section after immunogold labelling with anti-DNA; gold particles marking mtDNA are found near the mitochondrial membrane. (B) Whole mount view of cytoplasm after extraction with CSK buffer and immunogold labelling with anti-DNA; mtDNA (marked by gold particles) resists extraction. From Iborra et al., 2004.
Mitochondrial genome
–
Human mitochondrial DNA.
22.
Escherichia coli
–
Escherichia coli is a gram-negative, facultatively anaerobic, rod-shaped, coliform bacterium of the genus Escherichia that is commonly found in the lower intestine of warm-blooded organisms. Most E. coli strains are harmless, but some serotypes can cause food poisoning in their hosts. The harmless strains are part of the flora of the gut, and can benefit their hosts by producing vitamin K2. E. coli is expelled into the environment within fecal matter, the bacterium grows massively in fresh fecal matter under aerobic conditions for 3 days, but its numbers decline slowly afterwards. E. coli and other facultative anaerobes constitute about 0. 1% of gut flora, cells are able to survive outside the body for a limited amount of time, which makes them potential indicator organisms to test environmental samples for fecal contamination. A growing body of research, though, has examined environmentally persistent E. coli which can survive for extended periods outside of a host, the bacterium can be grown and cultured easily and inexpensively in a laboratory setting, and has been intensively investigated for over 60 years. E. coli is a chemoheterotroph whose chemically defined medium must include a source of carbon, under favorable conditions, it takes only 20 minutes to reproduce. E. coli is a Gram-negative, facultative anaerobic and nonsporulating bacterium, cells are typically rod-shaped, and are about 2.0 μm long and 0. 25–1.0 μm in diameter, with a cell volume of 0. 6–0.7 μm3. E. coli stains Gram-negative because its cell wall is composed of a peptidoglycan layer. During the staining process, E. coli picks up the color of the counterstain safranin, the outer membrane surrounding the cell wall provides a barrier to certain antibiotics such that E. coli is not damaged by penicillin. Strains that possess flagella are motile, the flagella have a peritrichous arrangement. E. coli can live on a variety of substrates and uses mixed-acid fermentation in anaerobic conditions, producing lactate, succinate, ethanol, acetate. Optimum growth of E. coli occurs at 37 °C, and it uses oxygen when it is present and available. It can, however, continue to grow in the absence of oxygen using fermentation or anaerobic respiration, the ability to continue growing in the absence of oxygen is an advantage to bacteria because their survival is increased in environments where water predominates. The bacterial cell cycle is divided into three stages, the B period occurs between the completion of cell division and the beginning of DNA replication. The C period encompasses the time it takes to replicate the chromosomal DNA, the D period refers to the stage between the conclusion of DNA replication and the end of cell division. The doubling rate of E. coli is higher when more nutrients are available, However, the length of the C and D periods do not change, even when the doubling time becomes less than the sum of the C and D periods. At the fastest growth rates, replication begins before the round of replication has completed, resulting in multiple replication forks along the DNA
Escherichia coli
–
Escherichia coli
23.
Cecropin
–
They were first isolated from the hemolymph of Hyalophora cecropia, whence the term cecropin was derived. Cecropins lyse bacterial cell membranes, they also inhibit proline uptake, cecropins constitute a main part of the cell-free immunity of insects. Cecropins are small proteins of about 31 -37 amino acid residues active against both Gram-positive and Gram-negative bacteria, cecropins isolated from insects other than Hyalophora cecropia have been given various names, bactericidin, lepidopterin, sarcotoxin, etc. All of these peptides are structurally related, members include, Cecropin A Peptide Sequence. Secondary structure includes two α helices, at low peptide to lipid ratios ion channels are formed, at high peptide to lipid ratios pores are formed. Secondary structure includes two α helices, papiliocin from Papilio xuthus an Asian swallowtail butterfly. An antibacterial peptide from Ascaris suum, a nematode that resides in the pig intestine. A derivative of Cecropin B is an anticancer polypeptide, structure consists of mainly alpha helixes, determined by solution NMR. Some of the cecropins have anticancer properties and are called anticancer peptides, hybrid ACPs based on Cecropin A have been studied for anticancer properties
Cecropin
–
Cecropin family
24.
Hemolin
–
Hemolin is an immunoglobulin-like protein exclusively found in Lepidoptera. It was first discovered in immune-challenged pupae of Hyalophora cecropia and Manduca sexta, Hemolin has a horseshoe crystal structure with four domains and resembles the developmental protein neuroglian. Hemolin increases 18-fold up to 7 mg/ml following injection of bacteria in H. cecropia, Hemolin has also been suggested to participate in the immune response to virus infection and shown to bind to virus particles. It is expressed in response to dsRNA in a dose-dependent manner, Hemolin is thought to be a gene duplication of the developmental protein neuroglian, but has lost two of the protein domains that neuroglian contains. RNAi of Hemolin causes malformation in H. cecropia
Hemolin
–
Hemolin from Hyalophora cecropia superimposed on neuroglian. Predicted differences between the proteins are highlighted in red. Made in Swiss Protein Database Viewer.
25.
Lysozyme
–
Lysozyme, also known as muramidase or N-acetylmuramide glycanhydrolase is an antimicrobial enzyme produced by animals that forms part of the innate immune system. This hydrolysis in turn compromises the integrity of cell walls causing lysis of the bacteria. Lysozyme is abundant in a number of secretions, such as tears, saliva, human milk and it is also present in cytoplasmic granules of the macrophages and the polymorphonuclear neutrophils. Large amounts of lysozyme can be found in egg white, c-type lysozymes are closely related to alpha-lactalbumin in sequence and structure, making them part of the same family. In humans, the enzyme is encoded by the LYZ gene. Lysozyme is thermally stable, with a melting point reaching up to 72 ℃ at pH5.0, however, in human milk it loses activity very fast at that temperature. In a large range of pH lysozyme can survive, the enzyme functions by attacking, hydrolyzing, and breaking glycosidic bonds in peptidoglycans. The enzyme can also break glycosidic bonds in chitin, although not as effective as true chitinases, the ability to break down both oligosaccharides suggests a similar mechanism between the breakdown of the two molecules. Lysozymes active site binds the peptidoglycan molecule in the prominent cleft between its two domains and it attacks peptidoglyans, its natural substrate, between N-acetylmuramic acid and the fourth carbon atom of N-acetylglucosamine. Shorter saccharides like tetrasaccharide have also shown to be viable substrates, chitin has also been show to be a viable lysozyme substrate. Artificial substrates have also developed and used in lysozyme. The Phillips Mechanism proposed that the enzymes catalytic power came from both steric strain on the substrate and electrostatic stabilization of the oxo-carbenium intermediate. From x-ray crystallography data, Phillips proposed the lysozymes active site binds to a hexasaccharide, the lysozyme distorts the fourth sugar in hexasaccharide into a half-chair conformation. In this stressed state, the bond is more easily broken. An ionic intermediate containing an oxo-carbenium is created as a result of the glycosidic bond breaking, thus distortion causing the substrate molecule to adopt a strained conformation similar to that of the transition state will lower the energy barrier of the reaction. This oxo-carbonium intermediate was proposed to be electrostatically stabilized by Arieh Warshel in 1978. Residues in the site, such as aspartate and glutamate are able to stabilize this intermediate. The electrostatic stabilization argument was based on comparison to bulk water, in Warshels model, the enzyme acts as a super-sovlent, which fixes the orientation of ion pairs and provides super-solvation, and especially lower the energy when to ions are close to each other
Lysozyme
Lysozyme
–
Lysozyme crystals stained with
methylene blue.
Lysozyme
Lysozyme
26.
Hemolymph
–
Hemolymph, or haemolymph, is a fluid, analogous to the blood in vertebrates, that circulates in the interior of the arthropod body remaining in direct contact with the animals tissues. It is composed of a plasma in which hemolymph cells called hemocytes are suspended. In addition to hemocytes, the plasma also contains many chemicals and it is the major tissue type of the open circulatory system characteristic of arthropods. In addition, some such as molluscs possess a hemolymphatic circulatory system. In the grasshopper, the portion of the system consists of tubular hearts. The hearts pump hemolymph into the sinuses of the hemocoel where exchanges of materials take place, the volume of hemolymph needed for such a system is kept to a minimum by a reduction in the size of the body cavity. The hemocoel is divided into chambers called sinuses, coordinated movements of the body muscles gradually bring the hemolymph back to the dorsal sinus surrounding the hearts. Between contractions, tiny valves in the wall of the hearts open, hemolymph fills all of the interior of the animals body and surrounds all cells. When not oxygenated, hemolymph quickly loses its color and appears grey, muscular movements by the animal during locomotion can facilitate hemolymph movement, but diverting flow from one area to another is limited. When the heart relaxes, blood is drawn back toward the heart through open-ended pores called ostia, note that the term ostia is not specific to insect circulation, it literally means doors or openings, and must be understood in context. Hemolymph can contain nucleating agents that confer extra cellular freezing protection, such nucleating agents have been found in the hemolymph of insects of several orders, i. e. Coleoptera, Diptera, and Hymenoptera. Hemolymph is composed of water, inorganic salts, and organic compounds, the primary oxygen transporter molecule is hemocyanin. Arthropod hemolymph contains high levels of amino acids. Most amino acids are present but their relative concentrations vary from species to species, concentrations of amino acids vary according to the arthropod stage of development. An example of this is the silkworm and its need for glycine in the production of silk Proteins present in the hemolymph vary in quantity during the course of development. These proteins are classified by their functions, chroma proteins, protease inhibitors, storage, lipid transport, enzymes, the vitellogenins, some hemolymphic proteins incorporate carbohydrates and lipids into the structure. Nitrogen metabolism end products are present in the hemolymph in low concentrations and these include ammonia, allantoin, uric acid, and urea. Arthropod hormones are present most notably the juvenile hormone, trehalose can be present and sometimes in great amounts along with glucose
Hemolymph
–
A grasshopper has an
open circulatory system, where hemolymph moves through interconnected sinuses or hemocoels, spaces surrounding the organs. Arthropod blood does not carry
hemoglobin.
27.
Lectin
–
Lectins are carbohydrate-binding proteins, macromolecules that are highly specific for sugar moieties. and used in biomedicine for blood cell testing and in biochemistry for fractionation. Lectins perform recognition on the cellular and molecular level and play roles in biological recognition phenomena involving cells, carbohydrates. Lectins also mediate attachment and binding of bacteria and viruses to their intended targets, for example, it is hypothesized that some hepatitis C viral glycoproteins attach to C-type lectins on the host cell surface for infection. The name lectin is derived from the Latin word legere, meaning, among other things, although they were first discovered more than 100 years ago in plants, now lectins are known to be present throughout nature. It is generally believed that the earliest description of a lectin was given by Peter Hermann Stillmark in his doctoral thesis presented in 1888 to the University of Dorpat, Stillmark isolated ricin, an extremely toxic hemagglutinin, from seeds of the castor plant. The legume lectins are probably the most well-studied lectins, most lectins do not possess enzymatic activity. They may bind to a soluble carbohydrate or to a moiety that is a part of a glycoprotein or glycolipid. They typically agglutinate certain animal cells and/or precipitate glycoconjugates, lectins serve many different biological functions in animals, from the regulation of cell adhesion to glycoprotein synthesis and the control of protein levels in the blood. They also may bind soluble extracellular and intercellular glycoproteins, some lectins are found on the surface of mammalian liver cells that specifically recognize galactose residues. It is believed that these receptors are responsible for the removal of certain glycoproteins from the circulatory system. Another lectin is a receptor that recognizes hydrolytic enzymes containing mannose-6-phosphate, i-cell disease is one type of defect in this particular system. Lectins also are known to important roles in the immune system. Within the innate immune system such as the MBL, the mannose-binding lectin. Other lectins within the system are thought to play a role in self-nonself discrimination and they likely modulate inflammatory. Intelectins were shown to bind microbial glycans and may function in the immune system as well. The function of lectins in plants is still uncertain, once thought to be necessary for rhizobia binding, this proposed function was ruled out through lectin-knockout transgene studies. The large concentration of lectins in plant seeds decreases with growth, the binding of glycoproteins on the surface of parasitic cells also is believed to be a function. It has been suggested that these interactions may be physiologically relevant, purified lectins are important in a clinical setting because they are used for blood typing
Lectin
–
Lateral hemagglutinine
28.
RNA interference
–
RNA interference is a biological process in which RNA molecules inhibit gene expression or translation, by neutralizing targeted mRNA molecules. Historically, it was known by names, including co-suppression, post-transcriptional gene silencing. Only after these apparently unrelated processes were fully understood did it become clear that all described the RNAi phenomenon. Mello shared the 2006 Nobel Prize in Physiology or Medicine for their work on RNA interference in the nematode worm Caenorhabditis elegans, since the discovery of RNAi and its regulatory potentials, it has become evident that RNAi has immense potential in suppression of desired genes. RNAi is now known as precise, efficient, stable and better than antisense technology for gene suppression, two types of small ribonucleic acid molecules – microRNA and small interfering RNA – are central to RNA interference. RNA interference has an important role in defending cells against parasitic nucleotide sequences – viruses, each siRNA is unwound into two single-stranded RNAs, the passenger strand and the guide strand. The passenger strand is degraded and the strand is incorporated into the RNA-induced silencing complex. In some organisms, this process spreads systemically, despite the initially limited molar concentrations of siRNA, the pathway is also used as a practical tool in biotechnology, medicine and insecticides. When the dsRNA is exogenous, the RNA is imported directly into the cytoplasm, the initiating dsRNA can also be endogenous, as in pre-microRNAs expressed from RNA-coding genes in the genome. The primary transcripts from such genes are first processed to form the characteristic structure of pre-miRNA in the nucleus. Thus, the two pathways, exogenous and endogenous, converge at the RISC. Bioinformatics studies on the genomes of multiple organisms suggest this length maximizes target-gene specificity and these short double-stranded fragments are called small interfering RNAs. These siRNAs are then separated into single strands and integrated into an active RISC, RLC includes Dicer-2 and R2D2, and is crucial to unite Ago2 and RISC. TATA-binding protein-associated factor 11 assembles the RLC by facilitating Dcr-2-R2D2 tetramerization, association with TAF11 would convert the R2-D2-Initiator complex into the RLC. R2D2 carries tandem double-stranded RNA-binding domains to recognize the thermodynamically stable terminus of siRNA duplexes, loading is asymmetric, the MID domain of Ago2 recognizes the thermodynamically stable end of the siRNA. Therefore, the passenger strand whose 5′ end is discarded by MID is ejected, after integration into the RISC, siRNAs base-pair to their target mRNA and cleave it, thereby preventing it from being used as a translation template. Differently from siRNA, a miRNA-loaded RISC complex scans cytoplasmic mRNAs for potential complementarity, exogenous dsRNA is detected and bound by an effector protein, known as RDE-4 in C. elegans and R2D2 in Drosophila, that stimulates dicer activity. This protein only binds long dsRNAs, but the mechanism producing this length specificity is unknown and this RNA-binding protein then facilitates the transfer of cleaved siRNAs to the RISC complex
RNA interference
–
A normal adult
Drosophila fly, a common model organism used in RNAi experiments.
RNA interference
–
Lentiviral delivery of designed shRNA's and the mechanism of RNA interference in mammalian cells.
29.
Instar
–
An instar is a developmental stage of arthropods, such as insects, between each moult, until sexual maturity is reached. Arthropods must shed the exoskeleton in order to grow or assume a new form, differences between instars can often be seen in altered body proportions, colors, patterns, changes in the number of body segments or head width. After moulting, i. e. shedding their exoskeleton, the juvenile arthropods continue in their life cycle until they pupate or moult again. This period of growth, instar, is fixed, some arthropods can continue to moult after sexual maturity, but the stages between these subsequent moults are generally not called instars. The number of instars an insect undergoes depends on the species, lower temperatures and humidity often slow the rate of development. The dictionary definition of instar at Wiktionary
Instar
–
Imperial moth (
Eacles imperialis) development from egg to pupa, showing all the different instars
Instar
–
Two instars of a caterpillar of
Papilio polytes
30.
Caterpillar
–
Caterpillars /ˈkætərˌpɪlər/ are the larval stage of members of the order Lepidoptera. As with most common names, the application of the word is arbitrary, caterpillars of most species are herbivorous, but not all, some are insectivorous, even cannibalistic. Some feed on other products, for example clothes moths feed on wool. Caterpillars as a rule are voracious feeders and many of them are among the most serious of agricultural pests. In fact many moth species are best known in their caterpillar stages because of the damage cause to fruits and other agricultural produce, whereas the moths are obscure. Conversely, various species of caterpillar are valued as sources of silk, as human or animal food, the origins of the word caterpillar date from the early 16th century. They derive from Middle English catirpel, catirpeller, probably an alteration of Old North French catepelose, cate, cat + pelose, caterpillars have soft bodies that can grow rapidly between moults. Only the head capsule is hardened, the mandibles are tough and sharp for chewing leaves. Behind the mandibles of the caterpillar are the spinnerets, for manipulating silk, antennae are present on either side of the labrum, but small and relatively inconspicuous. Some larvae of the Hymenoptera order can appear like the caterpillars of the Lepidoptera, such larvae are mainly seen in the sawfly family. Caterpillars can be confused with the larvae of sawflies, lepidopteran larvae can be differentiated by, the numbers of pairs of pro-legs, sawfly larvae have 6 while caterpillars have up to 5 pairs. The number of stemmata, the larvae have only two, while a caterpillar has six. The presence of crochets on the prolegs, these are absent in the Symphyta, sawfly larvae have an invariably smooth head capsule with no cleavage lines, while lepidopterous caterpillars bear an inverted Y or V. Many animals feed on caterpillars as they are rich in protein, as a result, caterpillars have evolved various means of defense. The appearance of a caterpillar can often repel a predator, its markings and certain body parts can make it seem poisonous, or bigger in size and thus threatening, some types of caterpillars are indeed poisonous. Caterpillars have evolved defenses against physical conditions such as cold, hot or dry environmental conditions, some Arctic species like Gynaephora groenlandica have special basking and aggregation behaviours apart from physiological adaptations to remain in a dormant state. Many caterpillars are cryptically colored and resemble the plants on which they feed and they may even have parts that mimic plant parts such as thorns. Their size varies from as little as 1 mm to about 75 millimetres, some look like objects in the environment such as bird droppings
Caterpillar
–
Caterpillar of
Papilio machaon
Caterpillar
–
A
Monarch butterfly (Danaus plexippus) caterpillar feeding on a leaf of the
Swamp Milkweed (Asclepias incarnata) in a private garden in
Lancaster, Pennsylvania.
Caterpillar
–
A
geometrid caterpillar or inchworm
Caterpillar
–
Crochets on a caterpillar's prolegs
31.
PubMed Identifier
–
PubMed is a free search engine accessing primarily the MEDLINE database of references and abstracts on life sciences and biomedical topics. The United States National Library of Medicine at the National Institutes of Health maintains the database as part of the Entrez system of information retrieval, from 1971 to 1997, MEDLINE online access to the MEDLARS Online computerized database primarily had been through institutional facilities, such as university libraries. PubMed, first released in January 1996, ushered in the era of private, free, home-, the PubMed system was offered free to the public in June 1997, when MEDLINE searches via the Web were demonstrated, in a ceremony, by Vice President Al Gore. Information about the journals indexed in MEDLINE, and available through PubMed, is found in the NLM Catalog. As of 5 January 2017, PubMed has more than 26.8 million records going back to 1966, selectively to the year 1865, and very selectively to 1809, about 500,000 new records are added each year. As of the date,13.1 million of PubMeds records are listed with their abstracts. In 2016, NLM changed the system so that publishers will be able to directly correct typos. Simple searches on PubMed can be carried out by entering key aspects of a subject into PubMeds search window, when a journal article is indexed, numerous article parameters are extracted and stored as structured information. Such parameters are, Article Type, Secondary identifiers, Language, publication type parameter enables many special features. As these clinical girish can generate small sets of robust studies with considerable precision, since July 2005, the MEDLINE article indexing process extracts important identifiers from the article abstract and puts those in a field called Secondary Identifier. The secondary identifier field is to store numbers to various databases of molecular sequence data, gene expression or chemical compounds. For clinical trials, PubMed extracts trial IDs for the two largest trial registries, ClinicalTrials. gov and the International Standard Randomized Controlled Trial Number Register, a reference which is judged particularly relevant can be marked and related articles can be identified. If relevant, several studies can be selected and related articles to all of them can be generated using the Find related data option, the related articles are then listed in order of relatedness. To create these lists of related articles, PubMed compares words from the title and abstract of each citation, as well as the MeSH headings assigned, using a powerful word-weighted algorithm. The related articles function has been judged to be so precise that some researchers suggest it can be used instead of a full search, a strong feature of PubMed is its ability to automatically link to MeSH terms and subheadings. Examples would be, bad breath links to halitosis, heart attack to myocardial infarction, where appropriate, these MeSH terms are automatically expanded, that is, include more specific terms. Terms like nursing are automatically linked to Nursing or Nursing and this important feature makes PubMed searches automatically more sensitive and avoids false-negative hits by compensating for the diversity of medical terminology. The My NCBI area can be accessed from any computer with web-access, an earlier version of My NCBI was called PubMed Cubby
PubMed Identifier
–
PubMed
32.
International Standard Serial Number
–
An International Standard Serial Number is an eight-digit serial number used to uniquely identify a serial publication. The ISSN is especially helpful in distinguishing between serials with the same title, ISSN are used in ordering, cataloging, interlibrary loans, and other practices in connection with serial literature. The ISSN system was first drafted as an International Organization for Standardization international standard in 1971, ISO subcommittee TC 46/SC9 is responsible for maintaining the standard. When a serial with the content is published in more than one media type. For example, many serials are published both in print and electronic media, the ISSN system refers to these types as print ISSN and electronic ISSN, respectively. The format of the ISSN is an eight digit code, divided by a hyphen into two four-digit numbers, as an integer number, it can be represented by the first seven digits. The last code digit, which may be 0-9 or an X, is a check digit. Formally, the form of the ISSN code can be expressed as follows, NNNN-NNNC where N is in the set, a digit character. The ISSN of the journal Hearing Research, for example, is 0378-5955, where the final 5 is the check digit, for calculations, an upper case X in the check digit position indicates a check digit of 10. To confirm the check digit, calculate the sum of all eight digits of the ISSN multiplied by its position in the number, the modulus 11 of the sum must be 0. There is an online ISSN checker that can validate an ISSN, ISSN codes are assigned by a network of ISSN National Centres, usually located at national libraries and coordinated by the ISSN International Centre based in Paris. The International Centre is an organization created in 1974 through an agreement between UNESCO and the French government. The International Centre maintains a database of all ISSNs assigned worldwide, at the end of 2016, the ISSN Register contained records for 1,943,572 items. ISSN and ISBN codes are similar in concept, where ISBNs are assigned to individual books, an ISBN might be assigned for particular issues of a serial, in addition to the ISSN code for the serial as a whole. An ISSN, unlike the ISBN code, is an identifier associated with a serial title. For this reason a new ISSN is assigned to a serial each time it undergoes a major title change, separate ISSNs are needed for serials in different media. Thus, the print and electronic versions of a serial need separate ISSNs. Also, a CD-ROM version and a web version of a serial require different ISSNs since two different media are involved, however, the same ISSN can be used for different file formats of the same online serial
International Standard Serial Number
–
ISSN encoded in an EAN-13 barcode with sequence variant 0 and issue number 5
33.
Wikispecies
–
Wikispecies is a wiki-based online project supported by the Wikimedia Foundation. Its aim is to create a free content catalogue of all species. Jimmy Wales stated that editors are not required to fax in their degrees, Wikispecies is available under the GNU Free Documentation License and CC BY-SA3.0. Benedikt Mandl co-ordinated the efforts of people who are interested in getting involved with the project. Databases were evaluated and the administrators contacted, some of them have agreed on providing their data for Wikispecies, the board of directors of the Wikimedia Foundation voted by 4 to 0 in favor of the establishment of a Wikispecies. The project was launched in August 2004 and is hosted at species. wikimedia. org and it was officially merged to a sister project of Wikimedia Foundation on September 14,2004. On October 10,2006, the project exceeded 75,000 articles, on May 20,2007, the project exceeded 100,000 articles with a total of 5,495 registered users. On September 8,2008, the project exceeded 150,000 articles with a total of 9,224 registered users, on October 23,2011, the project reached 300,000 articles. On June 16,2014, the project reached 400,000 articles, on January 7,2017, the project reached 500,000 articles. Wikispecies has disabled local upload and asks users to use images from Wikimedia Commons, Wikispecies does not allow the use of content that does not conform to a free license
Wikispecies
–
Screenshot of species.wikimedia.org home page on 3 May 2011
