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21.
Recent theory and empirical work suggests that there may be variation among females in mate preferences that is adaptive.
One of the possible mechanisms maintaining variability in preferences and preferred traits is that the benefits of mate choice
may depend on compatibility with potential mating partners. We examined fitness consequences of mate choice in a species of
fish, the sand goby, Pomatoschistus minutus with a special focus on mate compatibility. Females were given the opportunity to establish their mate preferences in a dichotomous
mate choice experiment. This information was then applied by mating the focal or control female with either the preferred
or the non-preferred male. The parental performance of the males of these four mating combinations was then measured. In a
separate experiment, we assessed the female differential allocation by determining the residual gonad weight of spawned females
as a measure of the proportion of eggs spawned. We also estimated the amount of filial cannibalism separately for both sexes.
Our results show that preferred males provided benefits in the form of an increased number of hatching eggs. This benefit
was the same when the male was mated with a focal or a control female. Hence, we found no support for benefits that depend
on mate compatibility. Neither did we find support for the hypothesis that females would lay a different number of eggs depending
on the male status. The results also indicate that male filial cannibalism has a strong role in determining hatching success
in this species. 相似文献
22.
Assuming that a male’s genetic characteristics affect those of his offspring, extra-pair copulation has been hypothesized
to increase heterozygosity of the progeny—the “genetic compatibility” hypothesis—and the genetic diversity within litters—the
“genetic diversity” hypothesis. We tested these two hypotheses in the alpine marmot (Marmota marmota), a socially monogamous mammal showing a high rate of extra-pair paternity (EPP). In a first step, we tested the assumption
that a male’s genetic characteristics (heterozygosity and genetic similarity to the female) affect those of his offspring.
Genetic similarity between parents influenced offspring heterozygosity, offspring genetic similarity to their mother, and
litter genetic diversity. The father’s heterozygosity also influenced litter genetic diversity but did not affect offspring
heterozygosity. Hence, heterozygosity seems not to be heritable in the alpine marmot. In a second step, we compared genetic
characteristics of extra-pair young (EPY) and within-pair young (WPY). EPY were less genetically similar to their mother but
not more heterozygous than WPY. EPY siblings were also less genetically similar than their WPY half siblings. Finally, the
presence of EPY promoted genetic diversity within the litter. Thus, our data support both the “genetic compatibility” and
the “genetic diversity” hypotheses. We discuss further investigations needed to determine the primary causes of EPP in this
species. 相似文献
23.
Katja?BargumEmail author Jacobus?J.?Boomsma Liselotte?Sundstr?m 《Behavioral ecology and sociobiology》2004,57(1):9-16
The genetic basis of morphological traits in social insects remains largely unexplored. This is even true for individual body size, a key life-history trait. In the social insects, the size of reproductive individuals affects dispersal decisions, so that small size in queens is often associated with reduced dispersal, and large size with long-range dispersal and independent colony founding. Worker size is connected to division of labour when workers specialize in certain tasks according to their size. In many species, variation in worker size has been shown to increase colony performance. In this study, we present the first evidence of an additive genetic component to queen size in ants, using maternal half sib analysis. We also compared intra-colony size variation in colonies with high (queen doubly mated) versus low (queen singly mated) genetic variability. We found a high and significant heritability (h2=0.51) for queen size in one of the two study years, but not in the other. Size variation among queens was greater in colonies headed by a doubly mated queen in one of the study years, but not in the other. This indicates that genetic factors can influence queen size, but that environmental factors may override these under some circumstances. The heritability for worker size was low (h2=0.09) and non-significant. Increased genetic diversity did not increase worker size variation in the colonies. Worker size appeared largely environmentally determined, potentially allowing colonies to adjust worker size ratios to current conditions.Communicated by J. Heinze 相似文献
24.
This controlled prospective study assesses the relative risks of first trimester chorionic villus sampling (CVS) versus mid-trimester gentic amniocentesis (GA). CVS subjects and amnio-centesis controls were comparable with regard to several confounding variables which might influence the risk of pregnancy loss including maternal age, smoking, alcohol consumption, gestational age at study entry, and history of vaginal bleeding or poor prior reproductive outcome. The most common indication for prenatal diagnosis was advanced maternal age (n = 511). In this subgroup, spontaneous abortion (<24 weeks) occurred in 2·9 per cent of CVS subjects versus 4−3 per cent of amniocentesis controls. The sum of spontaneous and therapeutic abortions (<24 weeks) was identical (5·3 per cent) in both groups. Therefore, intervention in the CVS group (i.e., therapeutic abortion for cytogenetic abnormalities) did not influence the observed risk of pregnancy loss. Overall perinatal mortality rates were also similar in both groups. No significant differences were identified for a number of pregnancy outcome parameters including 5 min Apgar score, birth weight, body length, head circumference, gestational age at delivery, preterm delivery, fetal growth retardation, congenital malformations, and neonatal complications. Preliminary results of this controlled prospective study suggest that chorionic villus sampling carries a low and acceptable risk. 相似文献
25.
《Process Safety and Environmental Protection》2014,92(6):723-731
Recently production of hydrogen from water through the Cu–Cl thermochemical cycle is developed as a new technology. The main advantages of this technology over existing ones are higher efficiency, lower costs, lower environmental impact and reduced greenhouse gas emissions. Considering these advantages, the usage of this technology in new industries such as nuclear and oil is increasingly developed. Due to hazards involved in hydrogen production, design and implementation of hydrogen plants require provisions for safety, reliability and risk assessment. However, very little research is done from safety point of view. This paper introduces fault semantic network (FSN) as a novel method for fault diagnosis and fault propagation analysis by using evolutionary techniques like genetic programming (GP) and neural networks (NN), to uncover process variables’ interactions. The effectiveness, feasibility and robustness of the proposed method are demonstrated on simulated data obtained from the simulation of hydrogen production process in Aspen HYSYS®. The proposed method has successfully achieved reasonable detection and prediction of non-linear interaction patterns among process variables. 相似文献
26.
本文以平遥县城及周边区域环境空气质量监测结果为依据,采用具有全局优化的遗传算法(GA)对平遥县及周边区域大气环境质量污染现状进行评价。用大气污染危害指数的普适公式和参数优化后的污染危害指数公式确定污染危害指数的取值范围与评价级别之间的对应关系,由此得出较符合平遥县及周边区域实际的评价结果,同时针对具体情况对此结果进行简单的分析。 相似文献
27.
28.
I. Ben TaloubaL. Balland N. Mouhab M.A. Abdelghani-Idrissi 《Journal of Loss Prevention in the Process Industries》2011,24(4):391-396
The thermal stability of organic peroxides (cumene hydroperoxide 80 wt% and dicumyl peroxide) was studied by means of calorimetric measurement (DSC, TA Q1000) in an isotherm mode and a dynamic mode. Analysis of power profiles released in the isothermal mode was combined with the analysis of the decomposed compounds by a gas chromatograph/mass spectrometer (GC/MS) to determine the reaction mechanisms corresponding to each of the two reactions. In this work, a methodology for estimating kinetic parameters was based on the comparison of the power profile (dynamic mode) given by the model to that obtained experimentally by changing the parameters values. Parameter estimation is achieved using the mixed estimation method where a genetic algorithm is combined with a locally convergent method. 相似文献
29.
在分析兴都库什-喜马拉雅地区生物资源和生物贸易特点基础上,本文就《国际生物多样性公约》框架下的《名古屋议定书》在本地区实施的主要机遇和挑战进行了分析。研究认为,本地区各国在具体执行议定书时面临的困难依然严峻,应该不断在议定书的法律框架下规范遗传资源以及相关传统知识的贸易、使用与共享机制。同时,不断完善法律体系建设,提高全民资源保护意识、建立良好信用制度,提高遗传资源获取和鉴定的科学技术水平。 相似文献
30.
石窟文物病害成因分析及其对策研究 总被引:2,自引:0,他引:2
本文在概述石窟寺主要病害的基础上,结合典型灾例,从气象气候因素、地震活动、水文特征、环境工程地质条件、石窟寺结构和龛内文物自身的特殊性以及人类社会行为因素等6个方面详细分析了石窟文物病害形成的内部作用因素和外部环境条件,强调了综合减灾的重要性,并提出了相应的减灾对策。本文旨在为石窟寺的科学保护和文物修复工作提供理论基础和实践依据 相似文献