نتایج جستجو برای: asexual reproduction
تعداد نتایج: 69702 فیلتر نتایج به سال:
Asexual organisms that are descended from ancient asexual lineages defy current thinking on the evolution of sexual reproduction; theoreticians have been anxious to explain away their existence. However, a number of groups of organisms, from ferns to rotifers, have been suggested to be anciently asexual, and favourable evidence is being accumulated. Furthermore, new techniques for assessing cla...
An enduring problem in evolutionary biology is the near ubiquity of sexual reproduction despite the inherent cost of transmitting only half the parent's genes to progeny. Queens of some ant species circumvent this cost by using selectively both sexual reproduction and parthenogenesis: workers arise from fertilized eggs, while new queens are produced by parthenogenesis. We show that queens of th...
Individuals who reproduce asexually have a two-fold advantage over their sexually-reproducing counterparts as they are able to reproduce twice as fast. Explaining why sexual reproduction is favoured over asexual reproduction therefore remains an important challenge in evolutionary biology. Various mechanisms involving resistance to parasites, adaptation to novel environments and helping to purg...
a new structure learning approach for bayesian networks (bns) based on asexual reproduction optimization (aro) is proposed in this letter. aro can be essentially considered as an evolutionary based algorithm that mathematically models the budding mechanism of asexual reproduction. in aro, a parent produces a bud through a reproduction operator; thereafter the parent and its bud compete to survi...
Explaining the overwhelming success of sex among eukaryotes is difficult given the obvious costs of sex relative to asexuality. Different studies have shown that sex can provide benefits in spatially heterogeneous environments under specific conditions, but whether spatial heterogeneity commonly contributes to the maintenance of sex in natural populations remains unknown. We experimentally mani...
A new structure learning approach for Bayesian networks (BNs) based on asexual reproduction optimization (ARO) is proposed in this letter. ARO can be essentially considered as an evolutionary based algorithm that mathematically models the budding mechanism of asexual reproduction. In ARO, a parent produces a bud through a reproduction operator; thereafter the parent and its bud compete to survi...
Asexual freshwater planarians reproduce by tearing themselves into two pieces by a process called binary fission. The resulting head and tail pieces regenerate within about a week, forming two new worms. Understanding this process of ripping oneself into two parts poses a challenging biomechanical problem. Because planarians stop "doing it" at the slightest disturbance, this remained a centurie...
Recent work has shown that, in the Amazonian fungus-growing ant Mycocepurus smithii, queens use exclusively asexual reproduction and the male sex seems to have disappeared from the species. This finding illustrates the remarkable diversity of reproductive systems in ants.
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