نتایج جستجو برای: reproductive allocation
تعداد نتایج: 175223 فیلتر نتایج به سال:
We have yet to understand fully how conditions during different periods of development interact to influence life-history structure. Can the negative effects of poor juvenile nutrition be overcome by a good adult diet, or are life-history strategies set by early experience? Here, we tested the influence and interaction of different nutritional quality during juvenile and sexual development on f...
A variety of sex allocation models is considered in which the reproductive returns on investment in males differ from the returns on investment in females, the amounts of resources available for reproduction vary in the population, the costs of making male and female reproductive structures differ, and the conception sex ratio may be fixed and there may be an initial minimum investment per offs...
In this study, we aimed to explore the effect of altitude on reproductive ingredient and sex allocation different colors Anemone obtusiloba in populations. The variations three four altitudinal gradients at eastern Qinghai Tibetan Plateau were examined. Our results showed that with increased altitude, gynoecium/flower, androceium/flower gynoecium/individual increased, but androceium/individual,...
Males that follow alternative reproductive tactics might differ in their investment into testis development and sperm production. The resource-allocation hypothesis predicts that males following a sneaker tactic should invest more into sperm production than dominant territorial males which should invest more into mate guarding. This hypothesis is supported by studies in species where individual...
The variability in the numbers of treatment cycles couples may undertake with assisted reproductive technology (ART) and the length of time they may have to wait between successive cycles of treatment make the evaluation of treatment efficacy and prognosis complicated. The cumulative pregnancy rate using the life table method of analysis is being used more frequently to estimate the effectivene...
Current research has determined that traits involved in reproductive strategies and processes of seed dynamics should be studied together, and under varying environments, in order to clarify their roles in the ecology of plant communities. Here, we analyzed reproductive traits (allocation to reproduction, efficiency of seed production, and seed size) at the community level and their relationshi...
Epidemiological models generally explore the evolution of parasite life-history traits, namely, virulence and transmission, against a background of constant host life-history traits. However, life-history models have predicted the evolution of host traits in response to parasitism. The coevolution of host and parasite life-history traits remains largely unexplored. We present an epidemiological...
The differential allocation hypothesis predicts that females modify their investment in a breeding attempt according to its reproductive value. One prediction of this hypothesis is that females will increase reproductive investment when mated to high-quality males. In birds, it was shown that females can modulate pre-hatch reproductive investment by manipulating egg and clutch sizes and/or the ...
Colonial waterbirds such as herons, egrets and spoonbills exhibit ecological characteristics that could have promoted the evolution of conspecific brood parasitism and extra-pair copulation. However, an adequate characterization of the genetic mating systems of this avian group has been hindered by the lack of samples of elusive candidate parents which precluded conducting conventional parentag...
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