| 单词 | paedogenesis |
| 释义 | paedogenesisenUKpae·do·gen·e·sisP0147450 (pē′dō-jĕn′ĭ-sĭs)paedogenesis(ˌpiːdəʊˈdʒɛnɪsɪs)paedogenesisenUKpaedogenesis:see neotenyneoteny, in biology, sexual maturity reached in the larval stage of some animals. Certain environmental conditions can inhibit the completion of metamorphosis; low temperature or lack of available iodine retard the action of the thyroid gland, the larval form may mature ..... Click the link for more information. . Paedogenesisreproduction by larval invertebrates. Unfertilized egg cells develop in the larvae, giving rise to a new generation. Paedogenesis is a form of parthenogenesis. The phenomenon was discovered in 1862 by N. V. Vagner in dipterous insects of the genus Miastor of the family Cecidomyiidae. The term “paedogenesis” was proposed in 1865 by K. M. Baer. In paedogenesis, the daughter larvae feed on the tissues of the maternal larva as endoparasites, rupturing their host’s cuticle and transferring to an independent existence. Sometimes, after several generations of parthenogenetic larvae, there appear larvae that undergo complete metamorphosis and yield adult males and females that reproduce sexually. Paedogenesis is an adaptation that compensates for inadequate fertility of adult forms, which are resettled passively. Both viviparous and oviparous paedogenetic larvae are characteristic of beetles of the family Micromalthidae, which are distributed in North America. Paedogenesis is also known among a number of marine cladoceran crustaceans (for example, the genus Podon). The development of embryos of rediae in the sporocysts and rediae of the first generation in digenetic flukes is another example of paedogenesis. M. S. GILIAROV paedogenesisenUKpaedogenesis(pē′dō-jĕn′ĭ-sĭs)paedogenesisA term of waning use for the production of larva; larvogenesis.paedogenesissexual reproduction in the larval or juvenile stage which may persist either temporarily or permanently, as in an axolotl. Humans resemble the juvenile stages of apes in several features, such as lack of hair, and paedogenesis may well have played an important part in the evolution ofHomo sapiens. Some structures are said to be neotonic if the juvenile appearance persists in adults; an example is the downy plumage of an ostrich. |
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