Moreover, there are no male raider ants: The eggs develop parthenogenetically, without sperm, creating phalanxes of genetically identical female clones.
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We are living through a Cambrian explosion of personalized information — every time we hit return, our preferences seem to reproduce themselves parthenogenetically.
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Komodo dragons have evolved to reproduce both sexually and parthenogenetically because they mainly live isolated in the wild and become violent when approached, according to the zoo.
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It reproduces parthenogenetically, and gives birth to fully developed young.
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During most of the season Daphnia reproduce parthenogenetically by producing subitaneous eggs.
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Last accessed 2008-12-19 It reproduces parthenogenetically, in contrast with the morphologically similar P. lobata, which reproduces sexually.
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No males of Epiperipatus imthurni have been found, and specimens from Trinidad were shown to reproduce parthenogenetically. This species is the only known velvet worm to reproduce via parthenogenesis.
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The young emerge from the mother soon after hatching. Eggs are parthenogenetically produced without meiosis and the offspring are clonal to their mother, so they are all female (thelytoky). The embryos develop within the mothers' ovarioles, which then give birth to live (already hatched) first-instar female nymphs. As the eggs begin to develop immediately after ovulation, an adult female can house developing female nymphs which already have parthenogenetically developing embryos inside them (i.e.
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In the genera Colias, Erebia, Euchloe, and Parnassius, a small number of species are known that reproduce semi-parthenogenetically; when the female dies, a partially developed larva emerges from her abdomen.
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Willis Davidge, a human fighter pilot, is stranded along with Jeriba Shigan, a Drac, on a hostile planet. The Drac are a race of aliens which are reptilian in appearance, and are hermaphrodites who reproduce parthenogenetically.
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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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For most of the year, Leptodora reproduces parthenogenetically, with males only appearing late in the season, to produce winter eggs which hatch the following spring. Leptodora is the only genus in its family, the Leptodoridae, and suborder, Haplopoda.
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A. spiraecola is an holocyclic species, meaning that they undergo sexual reproduction during part of its life cycle and reproduces entirely parthenogenetically over most of its geographical range. Where it is holocyclic and produces sexual morphs, the primary hosts are Spiraea or Citrus.
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Elatobium abietinum has an unusual life cycle and feeds solely on coniferous trees. Wingless adult females often continue feeding and producing young parthenogenetically throughout the winter. In spring, winged aphids are produced and fly to other trees. Young nymphs enter diapause during the summer, recommencing development in the autumn.
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When a ZW species, such as the Komodo dragon, reproduces parthenogenetically, usually only males are produced. This is due to the fact that the haploid eggs double their chromosomes, resulting in ZZ or WW. The ZZ become males, but the WW are not viable and are not brought to term.
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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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It is now known that at least this species, and possibly others in the genus Theotima, reproduce parthenogenetically. Its preferred habitat is litter composed of smaller leaves in second growth forests with understory shrubs or in those forests with damper and more easily decayed leaves such as mahogany. The species prefers elevations less than 800m.
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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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Thesprotia graminis, common name American grass mantis or grass-like mantis, is a species of praying mantis native to the Southern United States.Thesprotia graminis It is found in Florida and Georgia.Dichotomous Key to Species of Mantids that may occur in FloridaBugs in Cyberspace This species can reproduce parthenogenetically or through sexual reproduction. T. graminis is similar in appearance to Brunneria borealis.
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Parthenogenesis (amictic phase) dominates the monogonont life cycle, promoting fast population growth and colonization. In this phase males are absent and amictic females produce diploid eggs by mitosis which develop parthenogenetically into females that are clones of their mothers. Some amictic females can generate mictic females that will produce haploid eggs by meiosis. Mixis (meiosis) is induced by different types of stimulus depending on species.
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Specimens arising from sexually produced eggs have a completely straight and relatively shorter spine. In parthenogenetically produced animals, the spine features a kink in the middle (see figure). Previously, the kinked-spined animals were thought to be a separate species – Bythotrephes cederstroemi. After genetic analysis, it is now considered to be a form of B. longimanus, making Bythotrephes a monotypic genus, (one with only a single species).
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In autumn, aphids reproduce sexually and lay eggs. Environmental factors such as change in photoperiod and temperature, or perhaps a lower food quantity or quality, causes females to parthenogenetically produce sexual females and males. The males are genetically identical to their mothers except that, with the aphids' X0 sex-determination system, they have one fewer sex chromosome. These sexual aphids may lack wings or even mouthparts.
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In Parthenolecanium, males are born from unfertilized eggs but diploidy is briefly restored by fusion of haploid cleave nuclei and then one sex chromosome is lost through heterochromatinization. Females can reproduce parthenogenetically with six different variants based on whether males are entirely absent or not (obligate v. facultative parthenogenesis); the sex of fertilized v. unfertilized eggs; and based on how diploidy is restored in unfertilized eggs.
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They produce soldier castes capable of fortress defense and protection of their colony against both predators and competitors. In these groups, therefore, high relatedness alone does not lead to the evolution of social behavior, but requires that groups occur in a restricted, shared area. These species have morphologically distinct soldier castes that defend against kleptoparasites (parasitism by theft) and are able to reproduce parthenogenetically (without fertilization).
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In polyploid obligate parthenogens like the whiptail lizard, all the offspring are female. In many hymenopteran insects such as honeybees, female eggs are produced sexually, using sperm from a drone father, while the production of further drones (males) depends on the queen (and occasionally workers) producing unfertilized eggs. This means that females (workers and queens) are always diploid, while males (drones) are always haploid, and produced parthenogenetically.
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Their surface is covered with protruding inverted goblet-shaped platforms, whose terminal disc is surrounded by "teeth" which extend out into thin, fragile filaments. Stec and colleagues performed an experiment to see if females could reproduce parthenogenetically. Reproduction was not observed when individuals were separated and not allowed to mate, suggesting they cannot. Stec and colleagues sequenced four molecular markers: 18S rRNA, 28S rRNA, ITS-2, and mitochondrial COI.
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Many of the agamic imagines emerge in October. After overwintering, Cynips develops eggs parthenogenetically and their eggs develop in live buds as 'red-wart galls'. The infested buds become yellow, orange or a russet colour and are about long. These red-wart galls appear in May and the males and females of the bisexual generation emerge in June and produce the fertilized eggs which undergo development in the red-pea galls.
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The claspers contain subdermal siphon sacs that provide the propulsive power for sperm transfer. It is also possible that the siphon sacs assist with sawfish sperm competition by washing away rival sperm from the female's vagina before copulations. Smalltooth sawfish have recently been observed, for the first time, to reproduce parthenogenetically in the wild. About 3 percent of the sawfish living in a Florida estuary are the result of parthenogenesis.
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Both asexual and sexual reproduction can be found in sipunculans, although asexual reproduction is uncommon and has only been observed in Aspidosiphon elegans and Sipunculus robustus. These reproduce asexually through transverse fission, followed by regeneration of vital body components, with S. robustus also reproducing by budding. One species of sipunculan, Themiste lageniformis, has been recorded as reproducing parthenogenetically; eggs produced in the absence of sperm developed through the normal stages. Most sipunculan species are dioecious.
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In two studies, the quantity of overwintering eggs had a strong positive correlation with the severity of soybean aphid outbreaks in the following spring. Soybean aphid life cycle Eggs begin to hatch into fundatrices when temperatures in the spring reach . Colonization of buckthorn by soybean aphids in the spring can lead to curling of leaves and twigs. Near the blooming stage of buckthorn, fundatrices reproduce parthenogenetically to give viviparous birth to alatae.
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Haplodiploidy, in which unfertilized eggs give rise to males and fertilized eggs give rise to females, is also found in the order. This allows a single female to successfully colonize a host by parthenogenetically producing sons, which she can then mate with to produce more offspring. Also, one alternative to the haplodiploidy method of reproduction exhibited by these nematodes is reproduction by apomictic thelytoky. By this method, adult females parthogenetically create female offspring, and males do not exist.
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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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The woolly, white tufts and broad strips are the colonies of the beech scale insect that are formed in tiny crevices along the bark. An adult beech scale insect has a soft body, is yellow in color, ranges from 0.5 to 1.0 millimeter long, and has an elliptical shape. The beech scale insect also has a stylet that it uses to penetrate the bark of the tree for feeding purposes. There are no male beech scale insects and the female insects reproduce parthenogenetically.
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Lasaea rubra is a simultaneous hermaphrodite and the eggs are retained inside the mantle cavity while they develop. The veliger larval stage is omitted from the life cycle and when fully developed, juvenile molluscs are released and crawl away from the parent. Adults are found to be able to move in a day and juveniles twice that distance. The majority of individuals inhabiting the same rock crevice are found to be clones of each other, having been developed parthenogenetically from a common ancestor.
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The adult weevil is matte black with fused wing covers, and is unable to fly. It feeds at night on the outer edges of leaves, causing the leaves to have a notched margin. Broadleaved evergreen plants such as Camellia, Rhododendron, Euonymus and Bergenia are particularly prone to damage, although a wide range of different garden plants is susceptible to attack. Female weevils have the ability to reproduce parthenogenetically with fertilisation of eggs required to produce males, though no males have been observed.
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At the onset of autumn in temperate regions many species switch to the production of sexual forms, with each clone producing both egg-laying females and males. This switch is triggered by the longer nights in the autumn. Both sexual males and sexual females are produced parthenogenetically in response to external and/or internal cues, such as the amount of food present, the amount of daylight, and the quality of the leaf. However, sugarbeet root aphids are also capable of reproducing sexually.
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Also known as eusociality. Ovary activation in honeybee workers is inhibited by pheromones from the queen. In the Cape honeybee social parasites that are of the worker caste enter the colony and kill the resident queen, activate their own ovaries and parthenogenetically produce diploid female offspring (thelytoky) – behaviors that are all linked to a single locus on chromosome 13. The parasites produced queen-like pheromones falsely signally the presence of a queen suppressing the reproduction of worker's native to the colony and policing or destroying these eggs.
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Clover mites are polyphagous, feeding on a wide range of plants, including "lawn grasses, ornamental flowers, clover, dandelion, shepherd's purse, strawberry, daffodil, Salvia, Alyssum, and primrose". They are especially numerous in lawns with a heavy growth of succulent, well-fertilized grass. They do not cause any apparent harm to turf grass, but their feeding activity can turn the grass a silvery color and may stipple plants when heavy populations are present. Clover mites reproduce parthenogenetically, their eggs do not need to be fertilized and are entirely female.
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Empasca decedens is believed to be native to the Mediterranean region and is widely distributed here. However, it has been recorded in Middle Eastern countries such as Iran and Pakistan and also in various western Asiatic countries, including China, North Korea and India. Recently, E. decedens has been found in Madeira Island, along with 3 morphotypes of Empoasca which reproduce parthenogenetically. Although it has generally been considered that E. decedens is a Mediterranean species, several publications show that it has a much wider area of distribution.
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Some aphids show some of the traits of eusociality, joining insects such as ants, bees and termites. However, there are differences between these sexual social insects and the clonal aphids, which are all descended from a single female parthenogenetically and share an identical genome. About fifty species of aphid, scattered among the closely related, host-alternating lineages Eriosomatinae and Hormaphidinae, have some type of defensive morph. These are gall-creating species, with the colony living and feeding inside a gall that they form in the host's tissues.
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As protectress of the Royal House, she is represented as a uraeus, and functions with the fiery fury of the sun, In time, this led to her being considered as the personification of the primordial waters of creation. She is identified as a great mother goddess in this role as a creator. She is the personification of the primeval waters, able to give birth (create) parthenogenetically. Among the pairs of deities usually noted by the later ancient Egyptians, she is paired with Ptah-Nun.
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These supplementary reproductives only mature into primary reproductives upon the death of a king or queen, or when the primary reproductives are separated from the colony. Supplementaries have the ability to replace a dead primary reproductive, and there may also be more than a single supplementary within a colony. Some queens have the ability to switch from sexual reproduction to asexual reproduction. Studies show that while termite queens mate with the king to produce colony workers, the queens reproduce their replacements (neotenic queens) parthenogenetically.
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Chimaera obtained this way is phenotypically changed and passes it to the next generation). In 1966 Tarkowski developed a technique which enabled observing chromosome in oocytes, which has been widely used in early studies of embryo (Tarkowski, 1967; Cytogenetics). This publication is often cited, although has been publicised over 50 years ago. In later years professor Tarkowski with his collaborators showed for the first time in history that parthenogenetically activated mouse oocytes are able of developing until mid- gestation (Tarkowski, et al.,1970;Nature).
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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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Donna Noble finds herself regretting her decision to decline the Tenth Doctor's invitation to travel in the TARDIS. She has started investigating conspiracy theories in the hope that she will find him again. The Doctor and Donna, neither one aware of the other's involvement, both investigate Adipose Industries, which is marketing a special diet pill to the people of London. They find that the pills use latent body fat to parthenogenetically create small white aliens called Adipose that spawn at night and leave the host's body.
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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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An unusual aspect of P. surinamensis is that the species reproduces parthenogenetically, a form of asexual reproduction in which embryos develop from unfertilized eggs. P. surinamensis reproduce by thelytokous parthenogenesis, a type of parthenogenesis in which offspring are almost exclusively female clones. Thelytokous parthenesis is known in about 1% of known animal species. Optional thelkytokous parthenogenesis occurs in several cockroach species when females are isolated from males, including in the common domestic pests Blatta orientalis, Blattella germanica, and Periplaneta americana, but in P. surinamensis it is obligatory parthenogenesis, its sole means of reproduction.
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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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F. hepatica measures 2 to 3 cm and has a cosmopolitan distribution. F. gigantica measures 4 to 10 cm in length and the distribution of the species is limited to the tropics and has been recorded in Africa, the Middle East, Eastern Europe and south and eastern Asia. In domestic livestock in Japan, diploid (2n = 20), triploid (3n = 30) and chimeric flukes (2n/3n) have been described, many of which reproduce parthenogenetically. As a result of this unclear classification, flukes in Japan are normally referred to as Fasciola spp.
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Some larvae preferentially settle onto certain suitable substrates, The mottled anemone (Urticina crassicornis) for example, settles onto green algae, perhaps attracted by a biofilm on the surface. The brooding anemone (Epiactis prolifera) is gynodioecious, starting life as a female and later becoming hermaphroditic, so that populations consist of females and hermaphrodites. As a female, the eggs can develop parthenogenetically into female offspring without fertilisation, and as a hermaphrodite, the eggs are routinely self- fertilised. The larvae emerge from the anemone's mouth and tumble down the column, lodging in a fold near the pedal disc.
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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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Colonization is accomplished by immature stages and female bias is favored at low colonization densities by the fact that, unlike isolated males, isolated females are not lost to the gene pool because they can mate with their parthenogenetically produced sons. In the M. Adamson and D. Ludwig model, colonization was found to occur before mating and male progeny have no fitness unless they colonize a host that contains a female. The ability of a female to produce songs with which to mate is potentially central to the colonization process. This conclusion was specifically called to attention through the case of G. batrachiensis.
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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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As a consequence, the males will only have fathers and the queens only mothers, while the sterile workers are the only ones with both parents of both genders. These ants get both the benefits of both asexual and sexual reproduction—the daughters who can reproduce (the queens) have all of the mother's genes, while the sterile workers whose physical strength and disease resistance are important are produced sexually. Other examples of insect parthenogenesis can be found in gall-forming aphids (e.g., Pemphigus betae), where females reproduce parthenogenetically during the gall-forming phase of their life cycle and in grass thrips.
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This single set of chromosomes is duplicated in the egg, which develops parthenogenetically. Eggs receiving a Z chromosome become ZZ (male); those receiving a W chromosome become WW and fail to develop, meaning that only males are produced by parthenogenesis in this species. It has been hypothesised that this reproductive adaptation allows a single female to enter an isolated ecological niche (such as an island) and by parthenogenesis produce male offspring, thereby establishing a sexually reproducing population (via reproduction with her offspring that can result in both male and female young). Despite the advantages of such an adaptation, zoos are cautioned that parthenogenesis may be detrimental to genetic diversity.
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During this time, she also formed an at first antagonistic relationship with another Tomorrow Stories feature character, Greyshirt, the two of them eventually recognizing the other as their equal. This may have ended completely, or remains an on-again/off-again romance that Clarice remains silently jealous of, although no story has been definitive on this point. As stated, the current mythos of this character place Cobweb and her partner as eventually having children together parthenogenetically, passing along their identities to their children when they reach adulthood, and then joining their ancestors in Peru. This is a tradition that the current Cobweb and Clarice both accept, although no story yet has shown them in a rush to fulfill these obligations.
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Later, a young Martian female, capable of bearing children parthenogenetically by merely wishing it, gives birth to a child after falling in love with one of the human explorers, undoubtedly the first romance ever written between a man and an alien female. This heralds the rebirth of the Martian race and, with Man's help, the eventual reconquest of their planet. Rosny also penned five prehistoric novels: Vamireh (1892), Eyrimah (1893), the world-renowned classic La Guerre du Feu better known as Quest for Fire (1909) which served as the basis for the 1981 movie; Le Félin Géant [The Giant Cat] (1918) (sometimes known as Quest of the Dawn Man) and Helgvor du Fleuve Bleu [Helgvor of the Blue River] (1930). In it, he combined the notions of modern drama with the ability to depict Man's early days.
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When Candice returns to school, two dwarf children attack and kill Ruth in front of her class, and abscond with Candice to Somafree, with Frank in pursuit. Upon arriving at Somafree, Raglan tells Frank the truth about the dwarf children: they are the accidental product of Nola's psychoplasmic sessions; Nola's rage about her abuse was so strong that she parthenogenetically bore a brood of children who psychically respond and act on the targets of her rage, with Nola completely unaware of their actions. Realizing the brood are too dangerous to keep anymore, Raglan plots to venture into their quarters and rescue Candice, provided that Frank can keep Nola calm to avoid provoking the children. Frank attempts a feigned rapprochement long enough for Raglan to collect Candice, but when he witnesses Nola give birth to another child through a psychoplasmically-induced external womb, she notices his disgust when she licks the child clean.
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A series of pin-up art calendar pages in the ABC: A-Z special as well as a World's Finest Comics-homage in Tomorrow Stories Special #1 explain that Cobweb and Clarice are the latest in a long line of parthenogenetically-produced daughters, their mutual mothers and their ancestors both fulfilling the roles of the masked adventurer and her loving sidekick for centuries. (Already an often taboo- breaking series, this also injects a sense of incestuousness between the two figures, who are ostensibly raised as sisters, in addition to lesbianism.) Their lineage begins in the 16th century, when all the males of an Incan village in the remote Valley of Inca-Fingas are all slain by an avalanche while on their way to battle Spanish conquistadors. In order to continue their village, the high priestess Lula Lacalan and her stuttering handmaiden Cla- Cla-Cla emulate the local Desert Grassland Whiptail Lizards, which simulate sex to trigger pregnancy, and are miraculously successful. Their daughters are later able to escape the Valley and, also capable of parthenogenesis, both continue Lula's and Cla-Cla-Cla's lineages.
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