نتایج جستجو برای: fecundity
تعداد نتایج: 6624 فیلتر نتایج به سال:
We determined the blood meal size-fecundity relationship in Anopheles gambiae in the laboratory. Our primary interest was to determine whether the fecundity curve has a non-linear component, i.e.. does it decelerate towards an asymptote? Small and large adult females in their second gonotrophic cycle were fed on human hosts for predetermined lengths of time. Blood meal size was ascertained by w...
The armored catfish Hypostomus affinis is a widespread Loricariidae fish in the Lajes Reservoir (22 degrees 42'-22 degrees 50' S; 43 degrees 53'-44 degrees 05' W), the largest lentic environment in the Rio de Janeiro State, but little is known about their reproductive biology. One hundred and twenty five females, captured from January 1996 to December 1997, were used to assess ovarian developme...
Sexual size dimorphism varies substantially among populations and species but we have little understanding of the sources of selection generating this variation. We used path analysis to study how oviposition host affects selection on body size in a seed-feeding beetle (Stator limbatus) in which males contribute large ejaculates (nuptial gifts) to females. Females use nutrients in these ejacula...
The genealogical consequences of within-generation fecundity variance polymorphism are studied using coalescent processes structured by genetic backgrounds. I show that these processes have three distinctive features. The first is that the coalescent rates within backgrounds are not jointly proportional to the infinitesimal variance, but instead depend only on the frequencies and traits of geno...
The toxicity of nonylphenol (NP) to springtails was pronounced at 40 mg/kg dry weight soil, at which no animals survived. Body length and fecundity were the individual life-history traits significantly stimulated by sublethal concentrations of NP during a 64-day experiment. However, the effects of NP on these traits did not result in a statistically significant increase in population growth rat...
The purpose of this study was to develop age-specific survivorship and fecundity schedules for adult Plodia interpunctella (Hübner) relevant to maize storages, with special reference to the southeastern states (USA). Laboratory cultures were established with moths collected from farm-stored maize in South Carolina and maintained on cracked maize at 30 1C and 60% r.h. Age-specific schedules of s...
Research on relative brain size in mammals suggests that increases in brain size may generate benefits to survival and costs to fecundity: comparative studies of mammals have shown that interspecific differences in relative brain size are positively correlated with longevity and negatively with fecundity. However, as yet, no studies of mammals have investigated whether similar relationships exi...
We observed the changes in aggressiveness and fecundity of the anthracnose pathogen Colletotrichum acutatum on hot pepper, under the ambient and the twice-ambient treatments. Artificial infection was repeated over 100 cycles for ambient (25°C/400 ppm CO2) and twice-ambient (30°C/700 ppm CO2) growth chamber conditions, over 3 years. During repeated infection cycles (ICs) on green-pepper fruits, ...
The heritability of genome-wide fitness that is expected in finite populations is poorly understood, both theoretically and empirically, despite its relevance to many fundamental concepts in evolutionary biology. In this study, we used two independent methods of estimating the heritability of lifetime female fecundity (the predominant female fitness component in this population) in a large, out...
This paper revisits and extends an inquiry on the age-at-menarche differential fecundity hypothesis. Earlier studies have interpreted the difference in the onset of female pubertal maturation as indicative of biological differences in fecundity between early and late menarcheal women. Using the WFS data for Sudan, the authors address the entire reproductive life of the women in terms of their t...
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