"In some vertebrate species, like geckos for example, parthenogenetic embryos can develop fully to produce healthy live young, but there are no examples of parthenogenetic mammals known to science," lead author Tony Perry told Gizmodo.
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As previous research has shown, this compound prevents the parthenogenetic embryos from going into a state of arrest.
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Although Michelangelo would have been the last to tell us — he liked to present himself as a parthenogenetic wonder — he did have some art training.
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Previously, researchers have "tricked" eggs into developing into an embryo without fertilization, but the resulting embryos (known as parthenogenetic embryos) died after just a few days.
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One of the traits that makes this tick such an invasive pest is that it is a parthenogenetic species, which means it does not need males to reproduce.
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"These ticks are parthenogenetic, which means that females create diploid eggs (with a full set of the mother's DNA) that develop into adults without needing the DNA of a male," she wrote in an email.
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"Essentially, for the egg to be 'tricked' into initiating parthenogenetic development, one has to remove the activity that keeps it arrested in the meiotic cell cycle, and that, in effect, is what the SrCl2 does," explained Perry.
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Sometimes she wondered why she spent time with these SJWs, but it was hard to find other mom friends in New York, especially when you were parthenogenetic and it was just you and the nanny holding down the fort.
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In H.G. Wells's "Men Like Gods" (1923) plants "had been trained and bred to make new and unprecedented secretions, waxes, gums, essential oils and the like, of the most desirable quality", which could serve as a slightly flowery mission statement for half the companies in this TQ. In Charlotte Perkins Gilman's "Herland" (1915), a race of parthenogenetic women live in a cornucopian Eden they have fashioned through science to meet their every need.
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Not all colonies produce males and bisexual and parthenogenetic populations are known.
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Artemia parthenogenetica is a species or series of populations of parthenogenetic brine shrimps.
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At least two species of spiders in the family Oonopidae (goblin spiders), Heteroonops spinimanus and Triaeris stenaspis, are thought to be parthenogenetic, as no males have ever been collected. Parthenogenetic reproduction has been demonstrated in the laboratory for T. stenaspis.
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Crustacean reproduction varies both across and within species. The water flea Daphnia pulex alternates between sexual and parthenogenetic reproduction. Among the better-known large decapod crustaceans, some crayfish reproduce by parthenogenesis. "Marmorkrebs" are parthenogenetic crayfish that were discovered in the pet trade in the 1990s.
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Unlike most parthenogenetic reptiles, Lepidophyma lizards show very low genetic heterozygosity, suggesting a non-hybrid origin.
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General phylogenetic relationships within Timema (Law & Crespi, 2002). Species marked with ♀ are parthenogenetic (female only).
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A parthenogenetic species can undergo a more rapid population increase than a sexual species because all parthenotes are female and produce offspring, while in sexual species half of all individuals are males and do not give birth to offspring. Additionally, laboratory experiments have revealed that even obligate parthenotes retain the capability of incorporating new genetic material through sexual reproduction to form new parthenogenetic lineages, and the ability to outcross on occasion may explain the lengthy evolutionary persistence of some parthenogenetic species.
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While sex hormone levels in parthenogenetic Cnemidophorus uniparens mimic the cycles seen in their sexual relatives, their nervous systems appear to have evolved unique responses to female sex hormones. Male-like behavior in C. uniparens is correlated with high progesterone levels. This female-female pseudocopulation has also been found to enhance fecundity. A triploid parthenogenetic species in the genus Aspidoscelis, formerly part of Cnemidophorus, has been fertilized with sperm from a sexual species in the same genus to produce a new tetraploid parthenogenetic species in laboratory experiments.
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Artemia comprises sexually reproducing, diploid species and several obligate parthenogenetic Artemia populations consisting of different clones and ploidies (2n->5n).
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This species is parthenogenetic and all specimens collected so far have been female. They lay eggs or may bear live young. Up to eight offspring are produced - all female and all genetically identical. It has been proposed that the species be transferred to a new genus as Virgotyphlops braminus because of its obligate parthenogenetic nature.
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Berlin: Springer Publications, 99–131 In Caucasian rock lizards of genus Darevskia, which have six parthenogenetic forms of hybrid origin hybrid parthenogenetic form D. "dahli" has a broader niche than either of its bisexual ancestors and its expansion throughout the Central Lesser Caucasus caused decline of the ranges of both its maternal and paternal species.
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These snails are freshwater inhabitants of temperate and warm zones. Thiaridae are partly viviparous, partly ovoviviparous. Many, but not all species are parthenogenetic.
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The gall is caused by the parthenogenetic generation of Cynips divisa, which has been known by the synonyms Diplolepis divisa, Dryophanta divisa and Spathegaster verrucosus.
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Such experiments provide evidence that even truly parthenogenetic species are still capable of incorporating new genetic material and may therefore be capable of evolution. There are six parthenogenetic gecko species in five genera: Hemidactylus garnotii (Indo-Pacific house gecko), Hemidactylus vietnamensis (Vietnamese house gecko), Hemiphyllodactylus typus (dwarf tree gecko), Heteronotia binoei (Binoe’s gecko), Nactus pelagicus (pelagic gecko), and Lepidodactylus lugubris (mourning gecko). The often quoted parthenogeneetic species N. arnouxi is nomen rejectum (ICZN 1991) and therefore a synonym of N. pelagicus, while Gehyra ogasawarisimae is a misidentified L. lugubris. The gecko Lepidodactylus lugubris is a parthenogenetic species also known to engage in female-female copulation.
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In C. cursor colonies with a single queen, 96.4% of daughter queens arise from thelytokous parthenogenetic eggs, while 97.9% of daughter workers arise from fertilized eggs.
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Timema shepardi, Shepard's Timema, is a stick insect native to northern California. It was first identified in 1999. It is one of five parthenogenetic species of Timema.
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Several species of whiptail lizards are entirely female and no males are known.AAAS – All-Female Species of the Lizard Genus Cnemidophorus, Teiidae These all-female species reproduce by obligate parthenogenesis (obligate, because the lizards do not involve males and cannot reproduce sexually). Like all squamate obligate parthenogenetic lineages, parthenogenetic Teiids are hybrids. Two or more species rarely hybridize and the offspring are thought to occasionally be capable of reproduction without sperm.
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At least two species in the genus Dugesia, flatworms in the Turbellaria sub- division of the phylum Platyhelminthes, include polyploid individuals that reproduce by parthenogenesis. This type of parthenogenesis requires mating, but the sperm does not contribute to the genetics of the offspring (the parthenogenesis is pseudogamous, alternatively referred to as gynogenetic). A complex cycle of matings between diploid sexual and polyploid parthenogenetic individuals produces new parthenogenetic lines.
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From the point of view of the classical concept of a species, homosexual taxa cannot be assigned a species status due to the lack of exchange of genetic material between individuals within the same population. However, on the basis of morphological and cytogenetic characters, they are assigned a species rank. The appearance of parthenogenetic species is usually associated with the last, Wurm glaciation. Parthenogenetic rock lizards appeared about 10 thousand years ago when, due to the formation of mountain glaciers, the habitats of the parent bisexual species were disturbed, which led to the overlap of their ranges and the hybridogenic formation of parthenogenetic individuals better adapted to the conditions of short summers and long winters.
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Some bagworm species are parthenogenetic, meaning their eggs develop without male fertilization. Each bagworm generation lives just long enough as adults to mate and reproduce in their annual cycle.
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Moore, Michael C., Joan M. Whittier, and David Crews. "Sex steroid hormones during the ovarian cycle of an all-female, parthenogenetic lizard and their correlation with pseudosexual behavior." General and comparative endocrinology 60.2 (1985): 144-153. Parthenogenetic whiptails are unusual in that they engage in female-female courtship to induce ovulation, with one non- ovulating female engaging in courting behavior normally seen in males while the ovulating female assumes the typical female role.
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In 2011, it was announced that a parthenogenetic hybrid Aspidocelis was bred in the laboratory. This serves as a demonstration of how other hybrid parthenogens in this genus may have arisen.
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The widely distributed parthenogenetic Indo-Pacific house gecko Hemidactylus garnotii , was named in his honour.Beolens, Bo; Watkins, Michael; Grayson, Michael (2011). The Eponym Dictionary of Reptiles. Baltimore: Johns Hopkins University Press.
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The Chaetonotids are divided into two suborders, Multitubulatina and Paucitubulatina. Multitubulatina are marine, hermaphroditic strap-shaped organisms. Paucitubulatina are mostly freshwater, bowling pin shaped organisms that can be hermaphroditic, parthenogenetic or both.
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Leiolepis triploida, also known as the Thai butterfly lizard or Malaysian butterfly lizard, is a species of agamid lizard that is all-female (parthenogenetic). It is found in Southern Thailand and Peninsular Malaysia.
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Normal egg cells form after meiosis and are haploid, with half as many chromosomes as their mother's body cells. Haploid individuals, however, are usually non-viable, and parthenogenetic offspring usually have the diploid chromosome number. Depending on the mechanism involved in restoring the diploid number of chromosomes, parthenogenetic offspring may have anywhere between all and half of the mother's alleles. The offspring having all of the mother's genetic material are called full clones and those having only half are called half clones.
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In all parthenogenetic reptile species studied to date, chromosomal evidence supports the theory that parthenogenesis arose through a hybridization event, although members of the genus Lepidophyma may be exceptions to this rule. The original hybridization event is believed to occur between two related species and is often followed by backcrossing to either parent species to create triploid parthenogenetic offspring. As no crosses of two sexual species in captivity have ever produced parthenogenetic offspring, it is unclear how a hybridization event would actually lead to asexual reproduction. It is possible that parthenogenesis evolved as a way of overcoming sterility due to improper chromosomal pairing and segregation during meiosis in hybrids, and that rare hybrid individuals that could premeiotically duplicate their chromosomes could escape hybrid sterility by reproducing through parthenogenesis.
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Like many phasmids it is parthenogenetic so it can reproduce on its own by laying eggs. The eggs are ovoid-shaped with some distinguishable glyphics around them and a sponge-like shape on the top.
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Macrosiphum is a genus of aphid. During the summer populations are made of parthenogenetic females. In the fall, males and females are produced; they mate and females lay eggs that overwinter. There are 140 spp.
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Darevskia is a genus of wall lizards of the family Lacertidae living in the Caucasus, Iran and Turkey in forest and grassy habitats with numerous rock outcrops. Among rock lizards, 7 parthenogenetic species are known.
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These lizards live in the dry and sometimes harsh climate of the southwestern United States and northern Mexico. All these asexual species appear to have arisen through the hybridization of two or three of the sexual species in the genus leading to polyploid individuals. The mechanism by which the mixing of chromosomes from two or three species can lead to parthenogenetic reproduction is unknown. Recently, a hybrid parthenogenetic whiptail lizard was bred in the laboratory from a cross between an asexual and a sexual whiptail.
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Some sources consider the gray checkered whiptail to be a subspecies of the common checkered whiptail, Aspidoscelis tesselatus, whereas others grant it full species status. It is one of many lizard species known to be parthenogenetic.
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Timema douglasi is a stick insect native to northern California and southern Oregon. It was first identified in 1996 as a specialist feeder on old-growth Douglas fir. It is one of five parthenogenetic species of Timema.
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Telescoping generations can occur in parthenogenetic species, such as aphids or other life forms that have the ability to reproduce without ovum fertilization. This occurrence is characterized by a viviparous female having a daughter growing inside her that is also parthenogenetically pregnant with a daughter cell. This pattern of reproduction can also occur in certain mites that are not parthenogenetic, e.g. Adactylidium, in which the young hatch and mate within the mother, eating her from the inside and then escaping; in some species the males never escape, and in others they die shortly afterwards.
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Due to the doubled reproduction rate and successful resettlement, same-sex populations later began to exist independently of the parent species. Hybridization occurs in places where the ranges of parthenogenetic and bisexual species overlap, resulting in the appearance of triploid sterile females and a small number of males, with changes in the reproductive system (malfunctions in the formation of reproductive products, hermaphroditism). Nevertheless, presumably, these males are able to give offspring, which leads to the appearance of tetraploid hybrids. Sometimes males emerge from unfertilized eggs laid by parthenogenetic females.
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Brief strontium chloride exposure induces parthenogenetic activation of oocytesO'Neill GT, Rolfe LR, Kaufman MH. "Developmental potential and chromosome constitution of strontium-induced mouse parthenogenones" (1991) Mol. Reprod. Dev. 30:214-219 which is used in developmental biological research.
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There is a large white spot over most of the scutellum. This species shows an evident sexual dimorphism. Males are much smaller than the females and completely black. They are very rare, because the species is substantially parthenogenetic.
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Ctenomorphodes tessulatus, the tessellated stick insect, tessellated phasmid or tessulata stick insect, is a medium-sized, stick insect found in the Brisbane area of Australia. Fully grown males in mating season exhibit frenetic behaviour. This species is also parthenogenetic.
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Several species of parthenogenetic gastropods have been studied, especially with respect to their status as invasive species. Such species include the New Zealand mud snail (Potamopyrgus antipodarum), the red-rimmed melania (Melanoides tuberculata), and the Quilted melania (Tarebia granifera).
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Tenodera australasiae, the purple-winged mantis, is species of praying mantis. Found in Australia, it is common in most parts of Brisbane (QLD). Both males and females are capable of flight. The species has not been shown to be parthenogenetic.
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The hindwings are black or blackish fuscous.Leaf-Hoppers and their Natural Enemies Females are parthenogenetic and lay eggs on dead grass leaves. The first instar larvae must attempt to grasp a passing planthopper (superfamily Fulgoroidea) on which the larvae feed.
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Other major contributions include the directed differentiation of nuclear transfer embryonic stem cells and parthenogenetic stem cells into specific neuron types. His lab was also the first to demonstrate "therapeutic cloning" in a mouse model of a central nervous system disorder.
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Veins four and five often fade apically. They occur all over the world except in regions with permanent ice-cover. Despite their ubiquity and abundance, little is known about their economic or ecological impact. Some species are known to be parthenogenetic.
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This is because the species is parthenogenetic, with most reproduction occurring from unfertilized eggs that produce only females. Development takes place in three stages—larva, protonymph, and deutonymph. The maturation from egg to adult occurs during 12 to 24 days.
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While it is often assumed that parthenogenesis is an inferior evolutionary strategy to sexual reproduction because parthenogenetic species lack the ability to complement genetic mutations through outcrossing or are unable to incorporate new genetic material, research on parthenogenetic species has gradually revealed a number of advantages to this mode of reproduction. Triploid unisexual geckos of the species Heteronotia binoei have greater endurance and aerobic capacity than their diploid ancestors, and this advantage may be the result of polyploidy and a form of hybrid vigor. It has also been observed that obligate parthenotes are often found at high altitudes and in sparse or marginal habitats, a pattern known as "geographical parthenogenesis," and their distribution in suboptimal territories may be a result of their increased colonization ability. A single parthenogenetic individual can colonize a new territory and produce offspring, while for a sexual species multiple individuals would need to occupy a new habitat and come into contact with each other for mating in order for successful colonization to occur.
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Darevskia armeniaca, commonly known as the Armenian lizard or the Armenian rock lizard, is a parthenogenetic (unisexually breeding) species (or form) of Darevskia, a genus of lizards belonging to the family Lacertidae, the wall lizards. Darevskia armeniaca is native to the Armenian Highland.
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North of the Alps the species is parthenogenetic and is called Apterona helicoidella helicoidella. Only females are present in this subspecies. They form a case that looks like a small snail. The females grow within the case, becoming adults in the late summer.
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Meiosis II involves the separation of sister chromatids in both sexual and parthenogenetic species. This method of parthenogenesis is observed in obligate parthenotes, such as lizards in the genus Cnemidophorus and Lacerta, and also in certain facultative parthenotes like the Burmese python.
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They are hermaphrodites, the marine species producing eggs which develop directly into miniature adults. The freshwater species are parthenogenetic, producing unfertilised eggs, and at least one species is viviparous. Gastrotrichs mature with great rapidity and have lifespans of only a few days.
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The species is believed to be the result of extensive hybridization between the little striped whiptail, Aspidoscelis inornatus, the plateau spotted whiptail, Aspidoscelis septemvittatus, and the western Mexico whiptail, Aspidoscelis costatus. It is one of many lizard species known to be parthenogenetic.
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These mate, the females lay diapausing eggs and the life cycle starts again. Pea aphids can complete their whole reproductive cycle without shifting host plant. Several morphs exists in pea aphids. Besides differences between sexual and parthenogenetic morphs, winged and wingless morphs exist.
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Some invertebrate species that feature (partial) sexual reproduction in their native range are found to reproduce solely by parthenogenesis in areas to which they have been introduced. Relying solely on parthenogenetic reproduction has several advantages for an invasive species: it obviates the need for individuals in a very sparse initial population to search for mates, and an exclusively female sex distribution allows a population to multiply and invade more rapidly, potentially up to twice as fast. Examples include several aphid species and the willow sawfly, Nematus oligospilus, which is sexual in its native Holarctic habitat but parthenogenetic where it has been introduced into the Southern Hemisphere.
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The female lays 3 mm elliptical eggs that look like plant seeds. Like most phasmids, C. chronus flicks its eggs on the soil, where a little knob called the capitullum attracts ants to carry them to the ant refinery, where they hatch. This species is parthenogenetic.
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The claim of pseudocopulation was initially met with hesitation by some researchers,Collins, H. M. & Pinch, T. J. (1993). The Golem: What You Should Know about Science. Cambridge, United Kingdom: Cambridge University Press, pp. 109-119. and the behavior has not been observed in all parthenogenetic varieties.
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This species description is based on a parthenogenetic female. Its body is rounded and high, compressed laterally. Its maximum height is at the middle of the body, its height/length ratio being 0.75–0.8 in adults. Its dorsal margin is arched, the posterior margin being somewhat convex.
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Medauroidea extradentata is mainly parthenogenetic, meaning they are asexual, making males very rare in the species. The female drops hundreds of eggs onto the forest floor, these eggs hatch in a few months. The eggs of this species are mottled with black and white and capped with black.
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Procambarus is a genus of crayfish in the family Cambaridae, all native to North and Central America. It includes a number of troglobitic species, and the marbled crayfish (marmorkrebs), which is parthenogenetic. Originally described as a subgenus for four species, it now contains 161 species in 16 subgenera.
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Fiji and Tahiti and in French Polynesia including the following Society Islands: Tahiti, Mo'orea, Raiatea, Huahine.Myers M. J., Meyer C. P. & Resh V. H. (2000). "Neritid and thiarid gastropods from French Polynesian streams: how reproduction (sexual, parthenogenetic) and dispersal (active, passive) affect population structure". Freshwater Biology 44(3): 535–545. .
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Development is generally direct, though there are so-called Higgins larvae, which differ from adults in several respects. The animals have two sexes as adults. Very complex and plastic life cycles of pliciloricids include also paedogenetic stages with different forms of parthenogenetic reproduction. Fossils have been dated to the late Cambrian.
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Most freshwater species are parthenogenetic. The smooth or complex cuticle has a variable number of adhesive tubes, and the pharyngeal lumen of Chaetonotids is Y-shaped. A valve may be present at the junction of the pharynx and midgut. The epidermis in most organisms in this order is partly syncytial.
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Development of parthenogens to adulthood is slower. Fewer parthenogens survive to adulthood and the adult lifespan of parthenogens is reduced. These findings suggest that there are specific constraints in switching from a meiotic mode of reproduction requiring fertilization to a parthenogenetic mode in which zygotes develop in the absence of fertilization.
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Cnemidophorus neomexicanus is unusual in being a diploid parthenote, produced as a result of hybridization between C. inornatus (left) and C. tigris (right)Lowe, Charles H., and John W. Wright. "Evolution of parthenogenetic species of Cnemidophorus (whiptail lizards) in western North America." Journal of the Arizona Academy of Science (1966): 81-87.
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Demotina is a genus of leaf beetles in the subfamily Eumolpinae. There are over 50 described species in Demotina. The genus is native to Asia, Australia and Oceania, though one species (Demotina modesta) is an adventive species in the southeastern United States in North America. Some species are known to be parthenogenetic.
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Rock lizards are extremely rare on their own, usually forming settlements. The population density of parthenogenetic rock lizards can vary in a wider range than that of bisexual species: up to 200 individuals per 1 km of the route in unisexual species and up to 80 individuals in bisexual species, which is explained by the fact that parthenogenetic species are less aggressive and have a high population growth rate. Rock lizards are characterized by complex and diverse social systems, which, in particular, are characterized by stable long-term friendly relations between the male and the female and territorial or hierarchical relations between individuals of the same sex. The basis of the settlements of bisexual rock lizards are sedentary males and females with individual sites, often overlapping.
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For most of the year, reproduction is parthenogenetic, with eggs being produced by females without males being present in the population. In the autumn, parthenogenetically produced males begin to appear; males and females then reproduce sexually. The resulting eggs sink to the bottom where they overwinter, hatching the following year as nauplius-like larvae.
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Tarkhnishvili DN (2012) Evolutionary History, Habitats, Diversification, and Speciation in Caucasian Rock Lizards. In: Advances in Zoology Research, Volume 2 (ed. Jenkins OP), Nova Science Publishers, Hauppauge (NY), p.79-120 This genus is unique in containing the only known monoclonal parthenogenetic species, Lacerta rostombekovi, where the entire species originates from a single hybridization event.
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There are at least eight parthenogenetic species of Caucasian rock lizard in the genus Lacerta.Darevskii IS. 1967. Rock lizards of the Caucasus: systematics, ecology and phylogenesis of the polymorphic groups of Caucasian rock lizards of the subgenus Archaeolacerta. Nauka: Leningrad [in Russian: English translation published by the Indian National Scientific Documentation Centre, New Delhi, 1978].
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The species are parthenogenetic, and they consist only of females.Photos of only female species The females give birth in 3 months, with the period being as long as 4–5 months. Various gestation periods are different, and can take maximum from 9–12 months. The gestation can be shortened if the temperature is warm enough.
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J. Micr. Sci. 57, 329. 1913\. (With D. J. Lloyd.) On methods of producing artificial parthenogenesis in Echinus esculentus and the rearing of the parthenogenetic plutei through metamorphosis. Quart. J. Micr. Sci. 58, 523. 1914. (With de Morgan and H. M. Fuchs.) On the experimental hybridization of echinoids. Phil. Trans. B, 204, 255. 1917\.
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Of the known specific and generic diversity of nonmarine ostracods, half (1000 species, 100 genera) belongs to one family (of 13 families), Cyprididae. Many Cyprididae occur in temporary water bodies and have drought-resistant eggs, mixed/parthenogenetic reproduction, and the ability to swim. These biological attributes preadapt them to form successful radiations in these habitats.
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Inseminated sexual females will lay overwintering eggs, from which new parthenogenetic females will emerge in early spring. When the colony begins to become overcrowded, some winged females are produced. These disperse to infest other plants, where they continue to reproduce asexually. When temperatures become colder and day lengths shorter, sexual winged females and males appear.
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Demotina modesta is a species of leaf beetle. It is an adventive species in the southeastern United States in North America, while its native range includes Japan and Korea. It is very abundant on oaks. It is known to be parthenogenetic in part of its native range, and no males are known from North America.
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The meiotic mechanism for bypassing fertilization is an ongoing area of research. Primarily known from lab studies of parthenogenetic Aspidoscelis neomexicanus, simulated mating behavior can increase fertility. In this behavior known as pseudocopulation, one female assumes a male-like role and the other a female- like role. Individuals can switch roles throughout their life.
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Chaniotis B. N., Butler J. M., Ferguson F. F. & Jobin W. R. (1980). "Presence of males in Puerto Rican Thiara (Tarebia) granifera (Gastropoda: Thiaridae), a snail thought to be parthenogenetic". Caribbean Journal of Science 16: 95–97. PDF. Live sperm were present in the testes of these males but the genitalia were apparently non-functional.
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Panicle rice mites are parthenogenetic (virgin females can produce male offspring). The female will then mate with the male offspring and produce eggs. A mated female produces an average of 55 eggs in her lifetime. The lifecycle in the laboratory can vary from 3 days at 86 °F to 20 days at 68 °F.
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H. haemorrhoidalis are parthenogenetic therefore, male greenhouse thrips are rare. Female H. haemorrhoidalis have reproductive systems that consists of two ovaries, two lateral oviducts and an accessory gland.The reproductive accessory gland of the H. haemorrhoidalis consists of an apical bulb and a fine gland duct. At the base of the ovipositor is a sebific gland.
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Philip Cohen, "The boy whose blood has no father", New Scientist, 7.10.1995 While over a dozen similar cases have been reported since then (usually discovered after the patient demonstrated clinical abnormalities), there have been no scientifically confirmed reports of a non-chimeric, clinically healthy human parthenote (i.e. produced from a single, parthenogenetic-activated oocyte).
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Forewings dark fuscous ; a small costal spot before middle, and a larger dorsal spot before the tornus whitish ; outer half of cilia whitish. Hindwings grey.Meyrick, E., 1895 A Handbook of British Lepidoptera MacMillan, London pdf Keys and description Adults are on wing from May to June. It is a parthenogenetic species, with males being extremely rare.
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Australian emperor laying egg, guarded by the male Insect species make up more than two- thirds of all extant animal species. Most insect species reproduce sexually, though some species are facultatively parthenogenetic. Many insects species have sexual dimorphism, while in others the sexes look nearly identical. Typically they have two sexes with males producing spermatozoa and females ova.
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Its reproduction is typically parthenogenetic and viviparous and females produce unfertilized eggs which they retain within their bodies. The embryos develop within their mothers' ovarioles and the offspring are clones of their mothers. Female nymphs are born which grow rapidly and soon produce more female offspring themselves. In some instances, the newborn nymphs already have developing embryos inside them.
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In the 1950s, the Soviet biologist Georgy Shaposhnikov conducted experiments on aphids of the Dysaphis genus. By transferring them to plants normally nearly or completely unsuitable for them, he had forced populations of parthenogenetic descendants to adapt to the new food source to the point of reproductive isolation from the regular populations of the same species.
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Andricus kollari, also known as the marble gall, is a parthenogenetic species of wasp which causes the formation of marble galls on oak trees. Synonyms for the species include Cynips kollari, Andricus quercusgemmae, A. minor, A. indigenus and A. circulans. Confusingly, the term "marble gall" is used to describe both the species of wasp and the gall it causes.
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Carausius morosus insect Carausius morosus (the 'common', 'Indian' or 'laboratory' stick insect) is a species of Phasmatodea (phasmid) often kept as pets by schools and individuals. Culture stocks originate from a collection from Tamil Nadu, India. Like the majority of the Phasmatodea, C. morosus are nocturnal. Culture stocks are parthenogenetic females that can reproduce without mating.
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His botanical knowledge led to study of gall wasps . Working with the North American species Neuroterus quercus-batatus (Fitch) in a laboratory he bred from the parthenogenetic females the bi-sexual form. This species was then introduced onto Turkey oaks in the Halle Botanic Garden. The up to then sterile over decades trees produced fertile seeds (Hüsing, 1966).
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The first issue of Nemonymous, subtitled A Journal of Parthenogenetic Fiction and Late Labelling, appeared in November 2001. Nine issues have been published through July 2010. The final four editions were more like books than journals: Zencore (2007), Cone Zero (2008), Cern Zoo (2009) and Null Immortalis (2010). All stories saw their first publication in Nemonymous.
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By November winged forms have developed and eggs are laid before winter sets in. In warmer climates, parthenogenetic reproduction takes place throughout the year. The winged male insects are seldom encountered but have been observed in Germany, India and Argentina. The aphids tend to concentrate on the growing tips of plants, young leaves, shoots, flowers and developing seed pods.
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Though winged males occur in some sites in Europe, only the parthenogenetic wingless female form of Dahlica triquetrella has been recorded in Britain. The adult lives a very short time. The larvae feed on lichen and algae on trunks, rocks and old walls. This diet has to be supplemented by dead insects for development to be successful.
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Molecular identification of Reesa vespulae (Milliron) (Coleoptera: Dermestidae), a newly recorded species from Korea. Journal of Asia-Pacific Biodiversity 7(3): 305-307. This beetle can be identified by two reddish bands on its elytra, black setae, and antennae tipped with clubs divided into four segments. Only female individuals have been observed; it is believed to be parthenogenetic.
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The unfertilised cells eventually duplicated their DNA, boosting their chromosomes to 46. When the unfertilised cells hit a developmental block, the fertilised cells took over and developed that tissue. The boy had asymmetrical facial features and learning difficulties but was otherwise healthy. This would make him a parthenogenetic chimera (a child with two cell lineages in his body).
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Triops cancriformis has a very fast life cycle, and individuals become mature in about two weeks after hatching. Their populations can be gonochoric, hermaphroditic or androdioecious. The latter is a very rare reproductive mode in animals, in which populations are made of hermaphrodites, with a small proportion of males. Due to this lack of males, early researchers thought Triops were parthenogenetic.
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Rotifers are dioecious and reproduce sexually or parthenogenetically. They are sexually dimorphic, with the females always being larger than the males. In some species, this is relatively mild, but in others the female may be up to ten times the size of the male. In parthenogenetic species, males may be present only at certain times of the year, or absent altogether.
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Cytological studies have shown some 27 species of Crinum to be diploid with a normal chromosome count of 2n = 22. Abilio Fernandes found that the Orange River Crinum bulbispermum had a count of 2n = 66, and some desert Crinum macowanii 2n = 44. These polyploid species produce seeds that are often parthenogenetic triploid or diploids, lack vigour and seldom grow to mature plants.
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These develop into mature females in about seven to ten days. The life span of an adult is about 30 days. Population densities are at their highest in early summer, then decrease through predation and parasitism. In autumn, the lengthening of the night triggers the production of a single generation of sexual individuals (males and oviparous females) by the same parthenogenetic parent females.
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Gynocladius is a parthenogenetic genus in the subfamily Orthocladiinae (Chironomidae). A single species is recorded from Southeast Brazil, Gynocladius scalpellosus, described by Mendes, Sæther and Andrade-Morraye in 2005. The name stands for the presence of only females (gyneo, gyneco; woman, female in Greek). All life stages are known, but the sole record of this species is the type material.
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Meanwhile, sexual snail populations remained much more stable over time. However, Hanley et al. studied mite infestations of a parthenogenetic gecko species and its two related sexual ancestral species. Contrary to expectation based on the Red Queen hypothesis, they found that the prevalence, abundance and mean intensity of mites in sexual geckos was significantly higher than in asexuals sharing the same habitat.
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Andricus quercuscalicis (Burgsdorf, 1783) (Hymenoptera: Cynipidae)the first identification of the species. is a small gall wasp with an obligate two-phase life-cycle that requires both pedunculate oak (Q. robur L.) (or occasionally sessile oak Q.petraea L.) and Turkey oak (Quercus cerris L.). Therefore, as with most oak gall wasps, this species has alternate sexual and parthenogenetic (all female) generations.
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Lice are usually cryptically coloured to match the fur or feathers of the host. A louse's color varies from pale beige to dark gray; however, if feeding on blood, it may become considerably darker. Female lice are usually more common than males, and some species are parthenogenetic, with young developing from unfertilized eggs. A louse's egg is commonly called a nit.
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Pheretima is a genus of earthworms found mostly in New Guinea and parts of Southeast Asia. Species belonging to the genus Pheretima have a clitellum, which is a band of glandular tissue present on segments 14 to 16. Individuals are hermaphroditic and reproduction can be either sexual or parthenogenetic. Female genital pores lie on the ventral surface of segment 14.
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In bdelloid rotifers, females reproduce exclusively by parthenogenesis (obligate parthenogenesis),"Bdelloids: No sex for over 40 million years.". TheFreeLibrary. ScienceNews. Retrieved 30 April 2011. while in monogonont rotifers, females can alternate between sexual and asexual reproduction (cyclical parthenogenesis). At least in one normally cyclical parthenogenetic species obligate parthenogenesis can be inherited: a recessive allele leads to loss of sexual reproduction in homozygous offspring.
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Unlike most bagworms, the case is constructed of soil particles and feces instead of leaves and twigs. The snailcase bagworm begins constructing its case at birth and remains inside for the rest of its life. This subspecies is unusual in that it is parthenogenetic; all individuals are females, and they reproduce without mating. Each female produces one to two dozen eggs, which are deposited within the case.
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The species consists of a number of clonal genetic lineages thought to arise from different hybridization events. Surprisingly, parthenogenetic females of this species occasionally produce male offspring, which are thought to be the result of non-genetic hormonal inversions. While these males are anatomically normal, they produce abnormal sperm and are sterile. Parthenotes are also found in two species of the night lizard genus Lepidophyma.
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The aphid feeds on new buds and leaves. The virus is transmitted when the aphid introduces it into the phloem of the plant.Featured Creatures In most parts of the world, there is no sexual reproductive stage in the autumn as there is in other aphid species and there are no males and no eggs. All the individuals are viviparous parthenogenetic females all year round.
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The New Mexico whiptail (Aspidoscelis neomexicanus) is a female-only species of lizard found in the southwestern United States in New Mexico and Arizona, and in northern Mexico in Chihuahua. It is the official state reptile of New Mexico. It is one of many lizard species known to be parthenogenetic. Individuals of the species can be created either through the hybridization of the little striped whiptail (A.
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The flowers are inconspicuous, solitary or clustered, with no petals. It is dioecious, with male and female flowers on separate plants, though some female plants are parthenogenetic. The fruit is an edible bright yellow or orange globose berry 2.5–4 cm diameter, with the skin and flesh of a uniform colour and containing several small seeds. Production is often copious, weighing down the branches during the summer.
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Hewitson, L., Haavisto A, Simerly C, Jones J and Schatten G (1997) Microtubule organization and chromatin configurations in hamster oocytes during fertilization, parthenogenetic activation and after insemination with human sperm. Biol.Reprod. 57: 967–975. Hewitson L, Takahashi D, Dominko T, Simerly C, and Schatten G. (1998) Fertilization and embryo development to blastocysts after intracytoplasmic sperm injection in the rhesus monkey. Hum Reprod 13:3449-3455.
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The eggs of stick insects have a coating of calcium oxalate which makes them survive unscathed in the digestive tract of birds. It has been suggested that birds may have a role in the dispersal of parthenogenetic stick insect species, especially to islands. The Phasmatodea life cycle is hemimetabolous, proceeding through a series of several nymphal instars. Once emerged, a nymph will eat its cast skin.
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In reproductive biology, heterogamy is the alternation of differently organized generations, applied to the alternation between parthenogenetic and a sexual generation. This type of heterogamy occurs for example in some aphids. Alternately, heterogamy or heterogamous is often used as a synonym of heterogametic, meaning the presence of two unlike chromosomes in a sex.. For example, XY males and ZW females are called the heterogamous sex.
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Miomantis caffra (common name: Springbok Mantis) is a species of praying mantis native to Southern Africa. It appeared in New Zealand in 1978, and was found more recently in Portugal and Los Angeles, California, in North America Lessons About Love and Invasion from America's Foreign Mantises: Inside Science, likely spread through the exotic pet trade. Females are facultatively parthenogenetic and unmated females can produce viable offspring.
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Stenochrus portoricensis is a species of short-tailed whipscorpion in the family Hubbardiidae. They are mostly found in North and Central America, but their parthenogenetic lifestyle allows them to live in other parts of the world in temperate climates.Szymkowiak, Pawel, et al. “First Record of the Schizomid Stenochrus Portoricensis (Schizomida: Hubbardiidae) in Poland, with DNA Barcode Data.” Türk Zooloji Dergisi = Turkish Journal of Zoology.
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The marbled crayfish' or ', is a parthenogenetic crayfish that was discovered in the pet trade in Germany in the 1990s. Marbled crayfish are closely related to the "slough crayfish", Procambarus fallax, which is widely distributed across Florida. No natural populations of marbled crayfish are known. Information provided by one of the original pet traders as to where the marbled crayfish originated was deemed "totally confusing and unreliable".
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Trees that survive the direct effects of the infection are usually weakened and may die from secondary causes. The presence of HWA can be identified by its egg sacs, which resemble small tufts of cotton clinging to the underside of hemlock branches. In North America, the hemlock woolly adelgid asexually reproduces and can have two generations per year. Both generations are parthenogenetic and exclusively female.
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Around 80% of imprinted genes are found in clusters such as these, called imprinted domains, suggesting a level of co-ordinated control. More recently, genome-wide screens to identify imprinted genes have used differential expression of mRNAs from control fetuses and parthenogenetic or androgenetic fetuses hybridized to gene expression profiling microarrays, allele-specific gene expression using SNP genotyping microarrays, transcriptome sequencing, and in silico prediction pipelines.
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Dryocosmus are a genus of gall wasps. They are cyclically parthenogenetic insects that induce galls on plants in the family Fagaceae. According to recent studies, the genus includes some species previously considered as belonging to the genus Chilaspis, whereas Dryocosmus favus should be excluded of the genus. Dryocosmus and Chilaspis are closely related to the other oak gall wasp taxa (Aphelonyx, Plagiotrochus, Pseudoneuroterus, Trichagalma, and some Neuroterus species) Z.Acs et al.
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In some cases, such as Pelophylax esculentus, there is also endomeiosis prior to cell division, which means that the maternal chromosomes are duplicated and each egg contains identical pairs of chromosomes. Hybridogenesis can be described as a parthenogenetic-like mode of reproduction, since there is no continuing heredity in the paternal line . It has been documented in the European water frog complex of the genus Pelophylax, which includes three hybridogenic forms.
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Triaeris stenaspis is a species of spider in the family Oonopidae, with a pantropical distribution. It is also found in Iran and has been introduced into Europe. A very small spider, with a maximum body length of under , it has been shown to prey successfully on springtails. Only females have ever been found, and the species may be parthenogenetic, being able to produce female offspring from unfertilized eggs.
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The aphids that hatch from these eggs in the spring are wingless females known as stem mothers. These are able to reproduce asexually, giving birth to live offspring, nymphs, through parthenogenesis. The lifespan of a parthenogenetic female is about 50 days and during this period, each can produce as many as 30 young. The offspring are also females and able to reproduce without mating, but further generations are usually winged forms.
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Male ostracods have two penises, corresponding to two genital openings (gonopores) on the female. The individual sperm are often large, and are coiled up within the testis prior to mating; in some cases, the uncoiled sperm can be up to six times the length of the male ostracod itself. Mating typically occurs during swarming, with large numbers of females swimming to join the males. Some species are partially or wholly parthenogenetic.
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Triaeris is a genus of goblin spiders erected by Eugène Simon in 1890 for the species Triaeris stenaspis. It was described from females from the Lesser Antilles; specimens were found later in heated greenhouses around Europe. No males of T. stenaspis have ever been found and the species may be parthenogenetic. Its taxonomy is confused, and the number of species that should be placed in the genus is unclear.
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These beetles usually inhabit Polyporaceae or more rarely Corticiaceae bracket fungi. The larvae as well as the adults burrow inside the fungi, often choosing old specimens or old tissue. The whole development, from egg to adult, often takes as little as two months; some are parthenogenetic. A few species are pests of commercial fungi, as in the case of Cis chinensis, which infests dried fruiting-bodies of Ganoderma lucidum.
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Tarebia granifera is both parthenogenetic and ovoviviparous, although males have been reported. These are characteristics which are undoubtedly key to its success as an invader. For example, no males have been found amongst hundreds dissected from KwaZulu-Natal, it is probable that a few are present. Males were found in most (6/7) populations examined in Puerto Rico but were generally uncommon at up to 22.7% of the population (mean 4.6%).
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This made Hwang the first, unknowingly, to successfully perform the process of parthenogenesis to create a human embryon and, ultimately, a human parthenogenetic stem cell line. Matchaki recreated Woo-Suk's experiment in 2019 with seven successful human parthenogenetic stem cell lines thereby proving single-gender asexual reproduction as a viable option in humans. Helen Spurway, a geneticist specializing in the reproductive biology of the guppy, Lebistes reticulatus, claimed, in 1955, that parthenogenesis, which occurs in the guppy in nature, may also occur (though very rarely) in the human species, leading to so-called "virgin births". This created some sensation among her colleagues and the lay public alike.TIME magazine, November 28, 1955; Editorial in The Lancet, 2: 967 (1955) Sometimes an embryo may begin to divide without fertilisation but it cannot fully develop on its own, so while it may create some skin and nerve cells, it cannot create others (such as skeletal muscle) and becomes a type of benign tumor called an ovarian teratoma.
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Many Cyprididae occur in temporary water bodies and have drought-resistant eggs, mixed/parthenogenetic reproduction and ability to swim. These biological attributes pre-adapt them to form successful radiations in these habitats. Bennelongia is an interesting genus of the family Cyprididae. It may be the last true descendant genus of the Mesozoic (and now extinct) lineage of Cypridea, which was a dominant lineage of ostracod in non-marine waters in the Cretaceous.
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In all other cases of unisexual reptilian species that have been examined, multiple separate asexual lineages are present. As true parthenotes, Lacerta do not require stimulation from sperm to reproduce. The best-known and perhaps most evolutionarily derived example of parthenogenesis in reptiles occurs within the Teiid genus of whiptail lizards known as Cnemidophorus. This genus contains at least 13 truly parthenogenetic species, which originate from hybridization events between sexual Cnemidophorus species.
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As males have never been found, the species is thought to be parthenogenetic, although this has only been demonstrated in spiders kept under laboratory conditions. Individuals were reared from eggs and kept alive on a diet of springtails until they died. After hatching, they passed through three juvenile stages (instars), each lasting about a month and followed by a moult during which they increased in size. Adults lived on average about six months.
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Compsobuthus werneri female with young (white) A few arthropods, such as barnacles, are hermaphroditic, that is, each can have the organs of both sexes. However, individuals of most species remain of one sex their entire lives. A few species of insects and crustaceans can reproduce by parthenogenesis, especially if conditions favor a "population explosion". However, most arthropods rely on sexual reproduction, and parthenogenetic species often revert to sexual reproduction when conditions become less favorable.
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Springtails are currently used in laboratory tests for the early detection of soil pollution. Acute and chronic toxicity tests have been performed by researchers, mostly using the parthenogenetic isotomid Folsomia candida. These tests have been standardized. Details on a ringtest, on the biology and ecotoxicology of Folsomia candida and comparison with the sexual nearby species Folsomia fimetaria (sometimes preferred to Folsomia candida) are given in a document written by Paul Henning Krogh.
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Lacertids are remarkably similar in form, with slender bodies and long tails, but have highly varied patterns and colours, even within the same species. Their scales are large on the head, which often also has osteoderms, small and granular on the back, and rectangular on the underside. Most species are sexually dimorphic, with the males and females having different patterns. At least eight species from the Caucasus are parthenogenetic,Darevskii IS. 1967.
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It is a shrub or small tree growing to 6 m tall, with sharp, 3–6 cm long stem spines in the leaf axils. The leaves are alternately arranged, simple broad lanceolate, 5–10 cm long and 1–3 cm broad, with an entire or finely toothed margin. The flowers are inconspicuous, solitary or clustered, with no petals. It is dioecious, with male and female flowers on separate plants, though some female plants are parthenogenetic.
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Marbled crayfish are the only known decapod crustaceans to reproduce only by parthenogenesis. All individuals are female, and the offspring are genetically identical to the parent. Marbled crayfish are triploid animals, which may be the main reason for their parthenogenetic reproduction. It is hypothesized that marbled crayfish originated from an error in meiosis resulting in a diploid gamete, which was then fertilized and created a viable triploid individual in a single generation.
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Aphid giving birth to live female young Many aphids are parthenogenetic during part of the life cycle, such that females can produce unfertilized eggs, which are clones of their mother. All such young are females (thelytoky), so 100% of the population at these times can produce more offspring. Many species of aphid are also viviparous: the young are born live rather than laid as eggs. These adaptations enable aphids to reproduce extremely rapidly when conditions are suitable.
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Adult Floscularia ringens make parthenogenetic eggs that are kept in the tube. After the eggs hatch, the young stay in the maternal tube for a little time to finish developing before swimming off. A young Floscularia ringens has a cone-shaped body, short foot, little corona, and mastax with trophi, but it still seems to not be able to eat. In less than one day, the young Floscularia ringens makes a lasting connection to a substrate.
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In the most commonly used sense of the term, arrhenotoky is synonymous with haploid arrhenotoky or haplodiploidy: the production of haploid males from unfertilized eggs in insects having a haplodiploid sex-determination system. Males are produced parthenogenetically, while diploid females are usually produced biparentally from fertilized eggs. In a similar phenomenon, parthenogenetic diploid eggs develop into males by converting one set of their chromosomes to heterochromatin, thereby inactivating those chromosomes. This is referred to as diploid arrhenotoky or parahaploidy.
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Many collembolan species, mostly those living in deeper soil horizons, are parthenogenetic, which favours reproduction to the detriment of genetic diversity and thereby to population tolerance of environmental hazards. Parthenogenesis (also called thelytoky) is under the control of symbiotic bacteria of the genus Wolbachia, which live, reproduce and are carried in female reproductive organs and eggs of Collembola. Feminizing Wolbachia species are widespread in arthropods and nematodes, where they co-evolved with most of their lineages.
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These can be seen in the 1825 drawing and although the main growth was killed off by severe winters, new growths always appeared. Old wisteria trees are a feature of the verandah, together with passion flowers and banksia roses. The New Zealand cabbage tree in flower with Mr.J.Ll. Griffith in the foreground Galls (upper left and right). A knopper gall formed on an acorn on the branch of an English oak tree by the parthenogenetic gall wasp Andricus quercuscalicis.
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A Clitarchus hookeri moulting Clitarchus hookeri is geographically parthenogenetic, meaning that in some localities females do not mate to reproduce. Instead, they are able to produce fertile eggs without mating. In the South Island Clitarchus hookeri males are rare or absent, while in the North Island both asexual and sexual populations occur. Although females who reproduce asexually lay similar number of eggs and have similar hatching success as those who reproduce sexually, their eggs took longer to hatch.
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Bdelloidea (Greek βδελλα, bdella, "leech-like") is a class of rotifers found in freshwater habitats all over the world. There are over 450 described species of bdelloid rotifers (or 'bdelloids'), and Abstract. distinguished from each other mainly on the basis of morphology. The main characteristics that distinguish bdelloids from related groups of rotifers are exclusively parthenogenetic reproduction and the ability to survive in dry, harsh environments by entering a state of desiccation-induced dormancy (anhydrobiosis) at any life stage.
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The gall develops as a chemically induced distortion of an unopened leaf axillary or terminal bud, mostly on field rose (Rosa arvensis) or dog rose (Rosa canina) shrubs. The female lays up to 60 eggs within each leaf bud using her ovipositor. The grubs develop within the gall, and the wasps emerge in spring; the wasp is parthenogenetic with fewer than one percent being males. Previous synonyms for the species are Diplolepis bedeguaris, Rhodites rosae, and Cynips rosae.
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Because multiple hybridization events can occur, individual parthenogenetic whiptail species can consist of multiple independent asexual lineages. Within lineages, there is very little genetic diversity, but different lineages may have quite different genotypes. An interesting aspect to reproduction in these asexual lizards is that mating behaviors are still seen, although the populations are all female. One female plays the role played by the male in closely related species, and mounts the female that is about to lay eggs.
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Some insects use parthenogenesis, a process in which the female can reproduce and give birth without having the eggs fertilized by a male. Many aphids undergo a form of parthenogenesis, called cyclical parthenogenesis, in which they alternate between one or many generations of asexual and sexual reproduction. In summer, aphids are generally female and parthenogenetic; in the autumn, males may be produced for sexual reproduction. Other insects produced by parthenogenesis are bees, wasps and ants, in which they spawn males.
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Oonopidae are seldom seen by people as they are too small to be easily noticed. They are generally found in the leaf litter layer and under rocks, but they also constitute a significant component of the spider fauna living in the canopy of tropical rainforest. Three blind Afrotropical genera (Anophthalmoonops, Caecoonops, Termitoonops) are exclusively found in termite nests. A few species, such as the pantropical Heteroonops spinimanus and Triaeris stenaspis, are thought to be parthenogenetic as no males have yet been collected.
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The second generation tends to drop to the ground and spend the winter in a cocoon as a prepupa, pupating in the spring. Some may remain in a prepupal state for a longer period of up to three years. Sawflies such as this species that have been introduced into North America have found little competition from native sawfly species and become invasive pests. They have few predators or parasites in the New World and their parthenogenetic abilities have allowed them to thrive.
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The genus Acanthoxyla is the result of hybridisation and the many parthenogenetic lineages within this genus are morphologically different and many are triploid. The process of parthenogenesis means that identification of species cannot rely on the biological species concept. In 2016, a single male specimen of A. inermis was observed in the United Kingdom. Some lineages of Acanthoxyla are triploid but Acanthoxyla inermis is diploid and therefore males can be produced if one X-chromosome is lost during egg production.
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Ctenomorphodes tessulatus eggs will not hatch in dry conditions. The presence of sand or litter helps the young phasmatid to completely free its metathoracic legs - if the eggs are placed loosely on the surface the nymph frequently cannot accomplish this and usually dies still attached to the shell. Females are parthenogenetic so a single egg can start a population, occasionally causing defoliation.Whilst reaching adulthood the tesselated phasmid needs to keep feeding in order to grow, which can cause significant defoliation.
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It is unclear whether this relationship was ever consummated. His quest for Viole Falushe brings him into association with Drusilla Wayles, a parthenogenetic daughter of Jheral Tinzy, Viole Falushe's lifelong obsession, from whom he later parts rather than repeat the unhappy ending of his relationship with Alusz Iphigenia. At the end of the book, he meets another, slightly older, Drusilla, and the acquaintance appears mutually delightful. However, there is no sign of her by the time of the events chronicled in The Face.
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He then went to the University of Arizona in Tucson, Arizona, where he became a professor of ecology and evolutionary biology. His interests focused on the desert fauna, especially of the Sonoran Desert. He did many extensive studies, and in 1964 published The Vertebrates of Arizona. His research in the 1960s established the parthenogenetic reproduction of many whiptail lizard species, and also discovered that the desert pupfish can tolerate temperatures up to 44 °C (112 °F) and extremely low oxygen levels.
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A few species are parthenogenetic, having few, if any, males. Gonopods occur in a diversity of shapes and sizes, and in the range from closely resembling walking legs to complex structures quite unlike legs at all. In some groups, the gonopods are kept retracted within the body; in others they project forward parallel to the body. Gonopod morphology is the predominant means of determining species among millipedes: the structures may differ greatly between closely related species but very little within a species.
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New colonies are typically founded by a male-female pair, but alternatively sometimes by a same-sex female pair, in which case reproduction is parthenogenetic. New incipient colonies may also be founded by same-sex male pairs. These male pairs of termites cannot reproduce, but by cooperating they are able to survive long enough that one or both has the potential to later replace a male in another colony. This male can then reproduce by mating with the female there .
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The research team speculates that since smalltooth sawfish are so rare, females might sometimes fail to find a male during the mating season, inducing the parthenogenetic process. Elasmobranchs are ovoviparous, have relatively long gestation periods, and internal fertilization. The sawfish eggs hatch in the uterus and the young continue to grow without a placental connection to the mother. The fetal sawfish receives nourishment from a yolk sac and absorbs all the nutrients it can from the yolk before it is born.
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The lizards that hatch from these eggs are thus also parthenogens that can again produce identical eggs, resulting in an asexual, clonal population. Parthenogenetic species resulting from a single hybridization are diploid (that is, they have two sets of chromosomes just as sexual species do), but sometimes these females mate with other males, producing offspring which are triploid (that is, they have three sets of chromosomes, or 50% more than equivalent sexual species; see polyploidy). Over 30% of the genus Cnemidophorus are parthenogenic.
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His intensive study of spermatogenesis in Lepidosiren represented critical confirmation that the chromosome mechanism could provide a physical basis for Mendel's laws. Another meaningful contribution to Mendelian theory arrived at his work on inheritance in parthenogenetic crustacea. He found out that apart from rare mutations, the genetic constitution of these crustacea remained unchanged, generation after generation. This work provided the first direct evidence from animals that the segregation of genes is according to the segregation of homologous chromosomes at meiosis.
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Parthenogenetic/gynogenetic embryos have twice the normal expression level of maternally derived genes, and lack expression of paternally expressed genes, while the reverse is true for androgenetic embryos. It is now known that there are at least 80 imprinted genes in humans and mice, many of which are involved in embryonic and placental growth and development. Hybrid offspring of two species may exhibit unusual growth due to the novel combination of imprinted genes. Various methods have been used to identify imprinted genes.
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An Australian colony being studied produced several, while none were seen in a Florida colony in over 15 years of study. In a parthenogenetic moth the rate varied by how long a population was stabilized, which suggests the possibility that Australian colony may have developed parthengenesis more recently than the Florida colony. P. surinamensis has at least 21 diploid clones, born independently from sexual females, meaning the thelytokous parthenogenesis has evolved repeatedly. There are also 11 known triploid clones, produced by backcrosses between clones and P. indicus.
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Theotima minutissima, a small spider species found in abundance in the Caribbean National Forest, is believed to be parthenogenetic, meaning that it reproduces without fertilization by a male. Other terrestrial invertebrates described from Puerto Rico include earthworms and cave dwelling animals. Eighteen native species of earthworm have been described, with 11 species belonging to the family Glossoscolecidae, 3 to the family Megascolecidae, and 4 to the family Exxidae.The taxonomic classification provided in Hendrix (1995) has been revised and this article presents the current classification.
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Timema males, in sexual species of Timema, show a consistent pattern of courting behavior. The male climbs onto the back of the female and, after a short display of vibrating and waving, they proceed to mate. (Rejection by the female is possible but uncommon.) The male then rides on the female's back for up to five days, a behavior often referred to as "guarding" the female. Several species of Timema are parthenogenetic: that is, females can reproduce asexually, producing viable eggs without male participation.
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B. obscurus is known to be geographically parthenogenetic: North American populations of the species reproduce sexually, while European populations reproduce asexually and are triploids. A stridulatory apparatus has been observed on the upper sides of the wings of B. obscurus, the first known in representatives of the subfamily Eumolpinae. It takes a form of a darkened convex microstructure spot near the end of each wing, between the RS and Cu veins. Symbiotic bacteria are associated with symbiotic organs found in the gut of B. obscurus.
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These were a parthenogenetic type and thus apparently an early cultivar. This find predates the first known cultivation of grain in the Middle East by many hundreds of years. The 1889 book 'The Useful Native Plants of Australia’ records that Ficus aspera had the common names "Rough-leaved Fig", "Purple Fig" and "White Fig" and that Indigenous Australians of the Rockhampton region referred to them as "Noomaie" and in Cleveland Bay (Queensland) "Balemo". It also states that the fruit which is black can be eaten.
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Nauphoeta cinerea can reproduce by facultative parthenogenesis, that is, some are capable of switching from a sexual mode of reproduction to an asexual mode when isolated from males. However, fitness of parthenogenetically reproducing females is significantly lower than fitness of sexually reproducing females. Tenfold fewer offspring are produced by parthenogenesis due to decreases in both the number of offspring per clutch and the number of clutches produced. Parthenogenetic offspring are less viable than sexually produced offspring even in the benign conditions of the laboratory.
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The marbled crayfish (marmorkrebs) is parthenogenetic and its taxonomy is disputed Procambarus was originally described by Arnold Edward Ortmann in 1905 as a subgenus of a wider genus Cambarus, and originally contained only four species (P. williamsoni, P. diguieti, P. mexicanus and P. cubensis). The subgenus was elevated in 1942 to the taxonomic rank of genus by Horton H. Hobbs, Jr., who later erected most of the subgenera now recognised within the genus, in his 1972 monograph The subgenera of the crayfish genus Procambarus (Decapoda: Astacidae).
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In apomictic parthenogenesis, the offspring are clones of the mother and hence (except for aphids) are usually female. In the case of aphids, parthenogenetically produced males and females are clones of their mother except that the males lack one of the X chromosomes (XO). When meiosis is involved, the sex of the offspring will depend on the type of sex determination system and the type of apomixis. In species that use the XY sex- determination system, parthenogenetic offspring will have two X chromosomes and are female.
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Self-impregnated snake in Missouri has another 'virgin birth', UPI, 21 September 2015. Retrieved 3 October 2015. Some of these like the mourning gecko Lepidodactylus lugubris, Indo-Pacific house gecko Hemidactylus garnotii, the hybrid whiptails Cnemidophorus, Caucasian rock lizards Darevskia, and the brahminy blindsnake, Indotyphlops braminus are unisexual and obligately parthenogenetic. Other reptiles, such as the Komodo dragon, other monitor lizards, and some species of boas, pythons, filesnakes, gartersnakes and rattlesnakes were previously considered as cases of facultative parthenogenesis, but are in fact cases of accidental parthenogenesis.
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In 2012, facultative parthenogenesis was reported in wild vertebrates for the first time by US researchers amongst captured pregnant copperhead and cottonmouth female pit-vipers. The Komodo dragon, which normally reproduces sexually, has also been found able to reproduce asexually by parthenogenesis."No sex please, we're lizards", Roger Highfield, Daily Telegraph, 21 December 2006 A case has been documented of a Komodo dragon reproducing via sexual reproduction after a known parthenogenetic event,Virgin birth of dragons, The Hindu, 25 January 2007. Retrieved 3 February 2007.
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Earlier taxonomy treated P. surinamensis as a species with both sexual and asexual forms, reproducing asexually in some populations, but sexually in other populations. Roth in 1967 applied the name P. indicus (Fabricius, 1775) to the sexually-reproducing taxon from which the parthenogenetic form P. surinamensis is descended. While P. surinamensis is cosmopolitan, P. indicus is endemic to the Indomalayasian region and adjacent parts of Southeast Asia, and spread just to Hawaiian and Mauritian islands. In P. surinamensis, males are rarely born and are nonfunctional with frequency varying by population.
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Adult sawflies are short-lived, with a life expectancy of 7–9 days, though the larval stage can last from months to years, depending on the species. Parthenogenetic females, which do not need to mate to produce fertilised eggs, are common in the suborder, though many species have males. The adults feed on pollen, nectar, honeydew, sap, other insects, including hemolymph of the larvae hosts; they have mouth pieces adapted to these types of feeding. Sawflies go through a complete metamorphosis with four distinct life stages – egg, larva, pupa and adult.
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Adult male newly emerged from its cocoon Like all other hymenopteran insects, sawflies go through a complete metamorphosis with four distinct life stages – egg, larva, pupa and adult. Many species are parthenogenetic, meaning that females do not need fertilization to create viable eggs. Unfertilized eggs develop as male, while fertilized eggs develop into females (arrhenotoky). The lifespan of an individual sawfly is two months to two years, though the adult life stage is often very short (approximately 7 – 9 days), only long enough for the females to lay their eggs.
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This description is based on parthenogenetic female specimens. Its body possesses a well-expressed dorsal keel, and is relatively high and oval. Its posterodorsal angle is rounded, while the posterior margin can be moderately concave. The posteroventral angles are provided with 1–3 small denticles with broad bases, which carry small setules between them. It shows a row of approximately 100 short setules along the posterior margin of the inside of its carapace. Its ventral margin can be irregularly convex, with about 35–40 ventral setae, 8 of which are long.
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In Maine, wingless females known as fundatrices hatch out of over- wintering eggs in mid-May, at the base of buds near the top of small trees. Colonies form just below the first whorl of shoots and the reproduction at first is parthenogenetic and viviparous with the offspring being wingless. If disturbed, adults drop to the ground but nymphs move rapidly away on the trunk. Colonies are transitory, and by mid-June, most colonies are at the base of trees, at the root collar or on the roots.
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P. spyrothecae is green, red or yellow in color and smooth to the touch. The outer surface of this species develops as the edges of the petiole of Populus nigra thicken, flatten and twist. In parallel to the petiole's shape, a gall forms into a spiral shape similar to that of the inside of a snail's shell. The fundatrix, or parthenogenetic female aphid produced on the primary host plant from an overwintering fertilized egg, is pale green; these individuals allow the second generation alatae to form within the gall.
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The introduction of the Cape honey bee into northern South Africa poses a threat to East African lowland honey bees. If a female worker from a Cape honey bee colony enters an East African lowland honey bee nest, she is not attacked, partly due to her resemblance to the East African lowland honey bee queen. As she is capable of parthenogenetic reproduction, she may begin laying eggs which hatch as "clones" of herself, which will also lay eggs, causing the parasitic A. m. capensis workers to increase in number.
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Like males of hybrid origin, they have reproductive disorders, which may not interfere with their offspring. A small amount of parthenogenetic female males emerging from clutches is explained by frequently occurring mutations incompatible with life. Despite the fact that as a result of parthenogenesis, individuals are born that receive hereditary material only from the mother's body, a small intraspecific genetic diversity has been revealed due to mutational processes, genetic instability and the appearance of same-sex species as a result of repeated and independent crossing of parental species among themselves.
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Parthenogenesis. Several species of whiptail lizard (especially in the genus Aspidoscelis) consist only of females that have the ability to reproduce through parthenogenesis. Females engage in sexual behavior to stimulate ovulation, with their behavior following their hormonal cycles; during low levels of estrogen, these (female) lizards engage in "masculine" sexual roles. Those animals with currently high estrogen levels assume "feminine" sexual roles. Some parthenogenetic lizards that perform the courtship ritual have greater fertility than those kept in isolation due to an increase in hormones triggered by the sexual behaviors.
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Bdelloid rotifers reproduce exclusively asexually, and all individuals in the class Bdelloidea are females. Asexuality evolved in these animals millions of years ago and has persisted since. There is evidence to suggest that asexual reproduction has allowed the animals to evolve new proteins through the Meselson effect that have allowed them to survive better in periods of dehydration. Molecular evidence strongly suggests that several species of the stick insect genus Timema have used only asexual (parthenogenetic) reproduction for millions of years, the longest period known for any insect.
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In 2003, the mode of asexual reproduction in the bdelloid rotifers was wholly unknown. One theory of how obligate parthenogenesis arose in bdelloid rotifers was that parthenogenic lineages lost the ability to respond to sex-inducing signal, which is why these lineages retained their asexuality. The obligate parthenogenetic strains of bdelloid rotifers produce a sex-inducing signal but have lost the ability to respond to that signal. It was later discovered that the inability to respond to sex-inducing signals in obligate parthenogens was caused by simple Mendelian inheritance of the gene op.
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203-213) p. 209. Through his "beehive" birthplace Orion is linked to Potnia, the Minoan-Mycenaean "Mistress" older than Demeter--who was herself sometimes called "the pure Mother Bee". Winged, armed with toxin, creators of the fermentable honey (see mead), seemingly parthenogenetic in their immortal hive, bees functioned as emblems of other embodiments of the Great Mother: Cybele, Rhea the Earth Mother, and the archaic Artemis as honored at Ephesus. Pindar remembered that the Pythian pre-Olympic priestess of Delphi remained "the Delphic bee" long after Apollo had usurped the ancient oracle and shrine.
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Acorn cup galls develop as a chemically induced distortion of the growing acorn cups on oak trees, caused by gall wasps which lay eggs within the tissues of the acorn cup. The sexual phase appears on catkins as rounded structures (6 mm × 3–4 mm) possessing a characteristic point, and when young are covered with fine hairs. The galls, shiny and hard, turn red in colour and then black or dark purple. The asexual or parthenogenetic phase, about 10 mm across, develops on acorn cups of English oak Q. robur and sessile oak Q. petraea.
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Full clones are usually formed without meiosis. If meiosis occurs, the offspring will get only a fraction of the mother's alleles since crossing over of DNA takes place during meiosis, creating variation. Parthenogenetic offspring in species that use either the XY or the X0 sex- determination system have two X chromosomes and are female. In species that use the ZW sex-determination system, they have either two Z chromosomes (male) or two W chromosomes (mostly non-viable but rarely a female), or they could have one Z and one W chromosome (female).
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A list of the known unisexual vertebrates, pp. 19-23 in: Evolution and Ecology of Unisexual Vertebrates. R.M. Dawley and J.P. Bogart (eds.) Bulletin 466, New York State Museum, Albany, New York Other usually sexual species may occasionally reproduce parthenogenetically; the Komodo dragon and hammerhead and blacktip sharks are recent additions to the known list of spontaneous parthenogenetic vertebrates. As with all types of asexual reproduction, there are both costs (low genetic diversity and therefore susceptibility to adverse mutations that might occur) and benefits (reproduction without the need for a male) associated with parthenogenesis.
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This behavior is believed to have evolved to allow a doomed colony to produce drones which may mate with a virgin queen and thus preserve the colony's genetic progeny. A few ants and bees are capable of producing diploid female offspring parthenogenetically. These include a honey bee subspecies from South Africa, Apis mellifera capensis, where workers are capable of producing diploid eggs parthenogenetically, and replacing the queen if she dies; other examples include some species of small carpenter bee, (genus Ceratina). Many parasitic wasps are known to be parthenogenetic, sometimes due to infections by Wolbachia.
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Parthenogenesis in birds is known mainly from studies of domesticated turkeys and chickens, although it has also been noted in the domestic pigeon. In most cases the egg fails to develop normally or completely to hatching. The first description of parthenogenetic development in a passerine was demonstrated in captive zebra finches, although the dividing cells exhibited irregular nuclei and the eggs did not hatch. Parthenogenesis in turkeys appears to result from a conversion of haploid cells to diploid; most embryos produced in this way die early in development.
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In the past these three families mentioned above have been placed together in the same superfamily Aphidoidea. Generally, Phylloxeridae is placed together with Adelgidae in the superfamily Phylloxeroidea. In fact, bionomical similarity such as the oviparous parthenogenetic females observed in these two groups and morphological characters such as the reduction of forewing venation, and reduction of antennal segments have been used in the study of their phylogeny suggesting that they are closely related and leading to their placing as sister groups in Phylloxeroidea. Phylloxeridae together with Adelgidae form the oviparous aphids group which is monophyletic and is sister group to Aphidoidea (other aphids).
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Resting egg pouch (ephippium) and the juvenile daphnid that just has hatched from it Cladoceran from Daphnia genus giving birth. Magnification is 100X, technique of the illumination: dark field and polarized light Most Daphnia species have a life cycle based on "cyclical parthenogenesis", alternating between parthenogenetic (asexual) reproduction and sexual reproduction. For most of the growth season, females reproduce asexually. They produce a brood of diploid eggs every time they moult; these broods can contain as few as 1–2 eggs in smaller species, such as D. cucullata, but can be over 100 in larger species, such as D. magna.
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There are two distinct reproductive strategies within the species Trichoniscus pusillus. Many populations are, like most metazoans, bisexual and reproduce sexually; in other cases, females reproduce parthenogenetically, creating clones of themselves. The sexually reproducing form is diploid while the parthenogenetic form is triploid; since parthenogenesis always produces females, males are always diploid and can only be produced by sexual reproduction. The frequency of males in the population decreases from south to north (a latitudinal cline) and in increasingly open habitats, with no males observed in most of Scotland and Scandinavia, but more than 15% males in the Iberian and Apennine Peninsulas.
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Galls (upper left and right) formed on acorns on the branch of a pedunculate (or English) oak tree by the parthenogenetic generation Andricus quercuscalicis. The large 2 cm gall growth appears as a mass of green to yellowish-green, ridged, and at first sticky plant tissue on the bud of the oak, that breaks out as the gall between the cup and the acorn. If only a few grubs are developing within, then it may appear only as a group of bland folds. Where several grubs are competing for space the shape may become much more contorted, with several tightly bunched galls.
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Anecdotal reports and observations suggest that in KwaZulu-Natal the indigenous thiarid Melanoides tuberculata is becoming less common and pressure from the spread of Tarebia granifera, particularly at high densities, is a possible explanation. Like Tarebia granifera, Melanoides tuberculata is parthenogenetic and ovoviviparous, grows to a similar size, are similar in size at first birth and juvenile output. Data from several habitats where the species occur sympatrically show however that in all such situations Tarebia granifera becomes numerically dominant. Tarebia granifera is likely to impact on another South-African indigenous thiarid, the poorly known Thiara amarula in the saline St. Lucia estuary system.
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Genetic evidence has revealed ghost populations in many species, including modern bonobos and chimpanzees, allopolypoid frogs, polyploid parthenogenetic crayfish, a variety of plants, and humans. A study comparing the genomes of 69 modern bonobos and chimpanzees found between .9-4.2% of gene flow from ancient bonobos and an archaic great ape lineage to modern bonobos, allowing researchers to reconstruct 4.8% of this ghost population’s genome. Furthermore, previous models for European ancestry suggested that European populations descended from two ancient populations, but genetic evidence now suggests that a third “ghost population”, the Ancient North Eurasians, has also contributed to European ancestry.
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With the exception of the West Coast of the South Island, the current distribution of Clitarchus hookeri is widespread on both the North and South Islands of New Zealand. It is thought that its distribution restricted at the Last Glacial Maximum to refugia in the northern North Island and the east coast of the South Island. It is thought that parthenogenetic female members of the species were able to recolonize areas more favourably following the glacial retreat. South Island individuals and those from the southern region of the North Island form a single clade with very low genetic diversity.
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The repercussions of parthenogenesis in sharks, which fails to increase the genetic diversity of the offspring, is a matter of concern for shark experts, taking into consideration conservation management strategies for this species, particularly in areas where there may be a shortage of males due to fishing or environmental pressures. Although parthenogenesis may help females who cannot find mates, it does reduce genetic diversity. In 2011, recurring shark parthenogenesis over several years was demonstrated in a captive zebra shark, a type of carpet shark. DNA genotyping demonstrated that individual zebra sharks can switch from sexual to parthenogenetic reproduction.
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Brachycaudus helichrysi overwinters as fertilised eggs which hatch during the winter or early spring, before the plum and damson trees on which they are laid come into leaf. The fundatrices (viviparous parthenogenetic females produced on the primary host) feed at first at the base of buds but as the buds begin to expand, they move on to softer tissues, and later on to the new shoots and underside of the foliage. By May, some winged forms are beginning to appear and these fly to secondary hosts, such as Asteraceae, Chrysanthemum and Trifolium, where they found new colonies. The colonies on the primary host gradually die out.
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Galls (upper left and right) A knopper gall formed on an acorn on the branch of an English oak tree by the parthenogenetic gall wasp Andricus quercuscalicis. Herbivores are unable to digest complex cellulose and rely on mutualistic, internal symbiotic bacteria, fungi, or protozoa to break down cellulose so it can be used by the herbivore. Microbial symbionts also allow herbivores to eat plants that would otherwise be inedible by detoxifying plant secondary metabolites. For example, fungal symbionts of cigarette beetles (Lasioderma serricorne) use certain plant allelochemicals as their source of carbon, in addition to producing detoxification enzymes (esterases) to get rid of other toxins.
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Triops longicaudatus is usually greyish yellow or brown in color, and differs from many other species by the absence of the second maxilla. Apart from Triops cancriformis, it is the only tadpole shrimp species whose individuals display as many as three reproductive strategies: bisexual, unisexual (parthenogenetic), and hermaphroditic; see below. Triops cancriformis is easily recognizable by its yellow carapace with dark spots, whilst T. longicaudatus individuals have a uniform carapace. The species also appeared about 50 million years later, and, as its name suggests, its elongated tail structures (cercopods) are often nearly as long as the rest of the body; including the cercopods, the body may reach in length.
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This language has fallen out of favor due to misconceptions and pejorative connotations associated with the terms, and also a shift to nomenclature based on genetics. Intersex is in some caused by unusual sex hormones; the unusual hormones may be caused by an atypical set of sex chromosomes. One possible pathophysiologic explanation of intersex in humans is a parthenogenetic division of a haploid ovum into two haploid ova. Upon fertilization of the two ova by two sperm cells (one carrying an X chromosome and the other carrying a Y chromosome), the two fertilized ova are then fused together resulting in a person having dual genitalial, gonadal (ovotestes) and genetic sex.
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The young Picard failed his first Starfleet Academy entrance exam, and, upon admission, met with numerous ethical/scholastic difficulties during his cadet career, but went on to flourish, developing a lifelong passion for archaeology, and he became the first freshman to win the Academy marathon. Shortly after graduation, Picard was stabbed in the heart by a Nausicaan, leaving the organ irreparable and requiring replacement with a parthenogenetic implant; this would prove near-fatal later. Picard eventually served as first officer aboard the USS Stargazer, which he later commanded. During that time, he performed a warp-speed battle tactic that would become known as the Picard Maneuver.
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The investigation of the birth was conducted by the research team from Queen's University Belfast, Southeastern University in Florida, and Henry Doorly Zoo itself, and it was concluded after DNA testing that the reproduction was parthenogenetic. The testing showed the female pup's DNA matched only one female who lived in the tank, and that no male DNA was present in the pup. The pup was not a twin or clone of her mother, but rather, contained only half of her mother's DNA ("automictic parthenogenesis"). This type of reproduction had been seen before in bony fish, but never in cartilaginous fish such as sharks, until this documentation.
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One solution to gender oppression or social issues in feminist utopian fiction is to remove men, either showing isolated all-female societies as in Charlotte Perkins Gilman's Herland, or societies where men have died out or been replaced, as in Joanna Russ's A Few Things I Know About Whileaway, where "the poisonous binary gender" has died off. In speculative fiction, female-only worlds have been imagined to come about by the action of disease that wipes out men, along with the development of technological or mystical method that allow female parthenogenetic reproduction. The resulting society is often shown to be utopian by feminist writers. Many influential feminist utopias of this sort were written in the 1970s;Attebery, p. 13.
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Shearer, at right in middle horizontal row, with Victoria Hockey Club (of Baltimore) in 1895–1896. Cresswell Shearer, FRS (24 May 1874 - 6 February 1941), was a British zoologist and Cambridge lecturer in Experimental Embryology, where he motivated his students to develop a keen interest in hands-on research, inviting them to practical marine research experience at Plymouth Laboratory of the Marine Biological Association of the United Kingdom during the summer months. It is also where he and Dorothy J Lloyd worked as early pioneers on how to rear parthenogenetic sea-urchin larvae through metamorphosis. He also conducted research there with Harold Munro Fox and Walter de Morgan on the genetics of sea urchin hybrids.
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Separation of the genus Darevskia from the subfamily Lacertinae occurred approximately 12-16 million years ago, in the middle of the Miocene. Presumably, the ancestral form of the genus Darevskia penetrated the territory of the Western Caucasus in the Middle Miocene or in the Middle Pliocene, when there was a land connection between Asia Minor and the Balkans. The genus of rock lizards has 7 parthenogenetic species: D. armeniaca, D. bendimahiensis, D. dahli, D. rostombekovi, D. sapphirina, D. unisexualis and D. uzzelli, resulting from the hybridization of males and females of different bisexual species. Moreover, D. valentini and D. portschinskii always enter as paternal species, and D. mixta, D. nairensis, D. raddei always enter as maternal species.
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But the Forest is supposedly full of dangers; Candide wants the locals to help him travel through it. Every day he wakes up making plans to leave the village and go to "the City" "the day after tomorrow". One day this suddenly happens when his wife Nava asks him to accompany her to the nearest village and they go off the track unintentionally. In their travels he finds out there is more to the Forest people than just villagers, who are in fact a forgotten leftovers from a past way of life, now being slowly discarded by the advanced and much more powerful parthenogenetic all-female civilization based in and around lakes, in full control of the Forest.
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Andricus foecundatrix (formerly Andricus fecundator) is a parthenogenetic gall wasp which lays a single egg within a leaf bud, using its ovipositor, to produce a gall known as an oak artichoke gall, oak hop gall, larch-cone gall or hop strobileA Nature Observer's Scrapbook The gall develops as a chemically induced distortion of leaf axillary or terminal buds on pedunculate oak (Quercus robur) or sessile oak (Quercus petraea) trees. The larva lives inside a smaller hard casing inside the artichoke and this is released in autumn. The asexual wasp emerges in spring and lays her eggs in the oak catkins. These develop into small oval galls which produce the sexual generation of wasps.
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Another example is the one of competition for calling space in amphibians, where the calling activity of a species prevents the other one from calling in an area as wide as it would in allopatry. A last example is driving of bisexual rock lizards of genus Darevskia from their natural habitats by a daughter unisexual form; interference competition can be ruled out in this case, because parthenogenetic forms of the lizards never demonstrate aggressive behavior. This type of competition can also be observed in forests where large trees dominate the canopy and thus allow little light to reach smaller competitors living below. These interactions have important implications for the population dynamics and distribution of both species.
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Parthenogenetic baby Komodo dragon, Chester Zoo, England A Komodo dragon at London Zoo named Sungai laid a clutch of eggs in late 2005 after being separated from a male company for more than two years. Scientists initially assumed she had been able to store sperm from her earlier encounter with a male, an adaptation known as superfecundation. On 20 December 2006, it was reported that Flora, a captive Komodo dragon living in the Chester Zoo in England, was the second known Komodo dragon to have laid unfertilised eggs: she laid 11 eggs, and seven of them hatched, all of them male.Notice by her cage in Chester Zoo in England Scientists at Liverpool University in England performed genetic tests on three eggs that collapsed after being moved to an incubator, and verified Flora had never been in physical contact with a male dragon.
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On June 26, 2007, International Stem Cell Corporation (ISCC), a California- based stem cell research company, announced that their lead scientist, Dr. Elena Revazova, and her research team were the first to intentionally create human stem cells from unfertilized human eggs using parthenogenesis. The process may offer a way for creating stem cells that are genetically matched to a particular female for the treatment of degenerative diseases that might affect her. In December 2007, Dr. Revazova and ISCC published an article illustrating a breakthrough in the use of parthenogenesis to produce human stem cells that are homozygous in the HLA region of DNA. These stem cells are called HLA homozygous parthenogenetic human stem cells (hpSC-Hhom) and have unique characteristics that would allow derivatives of these cells to be implanted into millions of people without immune rejection.
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China has one of the most unrestrictive embryonic stem cell research policies in the world. In recent years, seeing the research opportunities that China's lax regulations provide, many expatriate Chinese scientists from the West are returning to China to establish stem cell research centers and laboratories there. As a result of the increased interest in this field of research, in 2003, the People's Republic of China Ministry of Science and Technology and Ministry of Health issued official ethical guidelines for human embryonic stem cell research in its territories. The guidelines strictly forbid any research aimed at human reproductive cloning and require that the embryos used for stem cell research come only from: # Spared gamate or blastocyst after in vitro fertilization (IVF) procedures; # Fetal cells from accidental spontaneous or voluntarily selected abortions; # Blastocyst or parthenogenetic split blastocyst obtained by somatic cell nuclear transfer technology; or # Germ cells voluntarily donated.
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