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1.
半人工饲料对细纹豆芫菁成虫的正效应   总被引:4,自引:0,他引:4  
用改良的玉米螟半人工饲料和天然饲料分别饲养同一批采自野外的细纹芫菁Epicauta mannerheimi成虫。10业后从两组各取20半雌虫和20头雄虫,经解剖、称重和测定各器官芫菁素含量,结果显示:相对于天然饲料,半人工饲料对虫体增重和生殖腺发育有较大促进作用,并提高了雄虫虫体和附腺中芫菁素含量。全程饲养的成虫其处理组的寿命和雌虫产卵量也高于对照组,产下的卵有88%的孵化率,并孵出正常幼虫。  相似文献   

2.
Sexual conflict reduces offspring fitness in zebra finches   总被引:5,自引:0,他引:5  
Royle NJ  Hartley IR  Parker GA 《Nature》2002,416(6882):733-736
Parental care is often costly; hence, in sexually reproducing species where both male and female parents rear their offspring (biparental care), sexual conflict over parental investment can arise. Such conflict occurs because each care-giver would benefit from withholding parental investment for use with another partner, leading to a reduction in the amount of care given by one parent at the expense of the other. Here we report experiments to explore the prediction from theory that parents rearing offspring alone may provide greater parental investment than when rearing offspring together with a partner. We found that when the number of offspring per parent, and hence the potential workload, were kept constant, offspring received a greater per capita parental investment from single females than from both parents working together, and that males reared by single mothers were more sexually attractive as adults than their biparentally reared siblings. This difference between single- and two-parent families is due to a reduction in care provided by females when they care together with a male, rather than laziness by males or differences in the begging behaviour of chicks, supporting the claim that sexual conflict in biparental care can reduce the quality of offspring raised.  相似文献   

3.
Greene E  Lyon BE  Muehter VR  Ratcliffe L  Oliver SJ  Boag PT 《Nature》2000,407(6807):1000-1003
The theory of sexual selection was developed to explain the evolution of highly exaggerated sexual ornaments. Now supported by vast empirical evidence, sexual selection is generally considered to favour individuals with the most extreme trait expression. Here we describe disruptive selection on a sexual ornament, plumage coloration, in yearling male lazuli buntings (Passerina amoena). In habitats with limited good-quality nesting cover, the dullest and the brightest yearlings were more successful in obtaining high-quality territories, pairing with females and siring offspring, than yearlings with intermediate plumage. This pattern reflects the way that territorial adult males vary levels of aggression to influence the structure of their social neighbourhood. Adult males showed less aggression towards dull yearlings than intermediate and bright ones, permitting the dull yearlings to settle on good territories nearby. Fitness comparisons based on paternity analyses showed that both the adults and dull yearlings benefited genetically from this arrangement, revealing a rare example of sexually selected male-male cooperation.  相似文献   

4.
对成年棕色田鼠 (Microtusmandarinus)的社会行为进行了实验室观察 .结果发现 ,当陌生的两只雄鼠相遇时 ,优势雄鼠和从属雄鼠间的社会行为有明显的区别 ,优势鼠接近、攻击、追赶对方的频次和持续时间明显的多于从属鼠 ,而从属鼠逃离和防御行为多于优势鼠 ;优势鼠的体重明显的大于从属鼠 ,而且攻击行为和社会探究行为的频次与体重呈正相关 ,非社会行为无明显的差别 .但当两只熟悉的雄鼠相遇时 ,则比陌生雄鼠相遇表现出较多的喜好行为和较少的攻击行为 .观察还发现 ,单独生活的异性个体相遇时表现出较少的攻击行为和较多的喜好行为 ;相反 ,和其它家庭成员生活的两个陌生异性个体相遇时表现出较多的攻击行为 .两个雌性相遇和两个雄性相遇表现出相似的行为模式 .以上结果表明 ,熟悉性、性别、个体大小、接触近况是影响棕色田鼠社会行为的重要因子 .  相似文献   

5.
中国石龙子头、体大小的性二态   总被引:16,自引:0,他引:16  
本文研究中国石龙子(Eumeceschinensis)头、体大小的性二态。成雄体长和体重略大于成雌,但在统计上无明显差异。雌雄亚成体相对头长,相对头宽和相对头高无显著差异。成雄相对头长、相对头宽和相对头高显著大于成雌和亚成体。亚成体相对头长、相对头宽和相对头高与成雌无显著差异。雄性性成熟后头部的生长显著大子雌性。  相似文献   

6.
黄颡鱼繁殖期不同时间段性别比例差异不显著,体长小于155mm区段,雌性个体显著多于雄性个体,性比显著偏离;体长大于155mm区段,几乎全为雄性。体长95mm~155mm区间的3个体长区段雌雄性别比例差异不显著。  相似文献   

7.
摘要: 目的 探讨高盐高蛋白饮食对 Dah1 / SS 大鼠血压、肾脏和消化道病理变化的影响。方法 将 30 只 SPF 级雄性 Dah1 / SS 大鼠随机分为 3 个组,即对照组、高盐组和高蛋白组,分别给予 0. 4% NaCl 普通低盐饲料、8% NaCl 高盐饲 料和 2. 4% 蛋氨酸饲料,喂养 2 个月,每周测量体质量及收缩压 1 次。实验结束,取大鼠肾脏、食管、胃、小肠、直肠 及胰腺经 HE 染色后进行病理学观察。结果 高盐、高蛋白组大鼠体质量增长明显低于对照组; 高盐组大鼠收缩压 高于对照组和高蛋白组大鼠,差异有统计学意义,高蛋白组大鼠未见血压升高; 高盐及高蛋白组大鼠出现了不同程 度的肾功能损伤,高盐组大鼠出现了肾脏病理性损伤; 高盐和高蛋白饮食未见消化道及胰腺损伤。结论 Dah1 / SS 大鼠高盐饮食可成功建立盐敏感性高血压模型,且高盐高蛋白饮食对肾脏会造成不同程度的损伤,而对消化道及 胰腺未造成损伤。  相似文献   

8.
灭幼脲对云斑天牛成虫寿命和取食活动的影响   总被引:7,自引:2,他引:5  
测定了灭幼脲对云斑天牛成虫寿命和取食活动的影响。用100.0mg/kg灭幼脲水溶液处理的和对照的野蔷薇枝条混合水培饲养成虫,试验初期,成虫对处理与对照枝条无明显取食选择性;  相似文献   

9.
Garcia CM  Ramirez E 《Nature》2005,434(7032):501-505
Conventional models explaining extreme sexual ornaments propose that these reflect male genetic quality or are arbitrary results of genetic linkage between female preference and the ornament. The chase-away model emphasizes sexual conflict: male signals attract females because they exploit receiver biases. As males gain control of mating decisions, females may experience fitness costs through suboptimal mating rates or post-copulatory exploitation. Elaboration of male signals is expected if females increase their response threshold to resist such exploitation. If ornaments target otherwise adaptive biases such as feeding responses, selection on females might eventually separate sexual and non-sexual responses to the signal. Here we show that the terminal yellow band (TYB) of several Goodeinae species evokes both feeding and sexual responses; sexual responsiveness phylogenetically pre-dates the expression of the TYB in males and is comparable across taxa, yet feeding responsiveness decreases in species with more elaborated TYBs. Displaying a TYB is costly, and thus provides an example where a trait arose as a sensory trap but has evolved into an honest signal.  相似文献   

10.
白头叶猴社会行为谱包括性行为、友好行为和争斗行为3类,对G群中取代和臣服行为的分析发现,有3只公猴的地位最高,它们之间又呈线性等级关系,其他个体间的关系则比较复杂不呈线性。个体间亲密系数的聚类分析结果显示母猴间的关系最为亲密,地位最高的2只成年公猴之间存在着联盟关系。母猴是主要的梳理者,梳理其他个体的次数占70.7%,而未成年公猴主要接受梳理,它们梳理其他个体的次数只占2.8%,而被梳理的次数却占33.1%。2只成年公猴之间以及与母猴之间的具有倾向性的梳理关系是和等级关系相一致的。白头叶猴两性的社会行为存在明显差异。公猴积极参与到群间争斗中,保卫群中个体的安全以及领域,这些行为更符合配偶保卫假说。  相似文献   

11.
Liu Y  Jiang Y  Si Y  Kim JY  Chen ZF  Rao Y 《Nature》2011,472(7341):95-99
Although the question of to whom a male directs his mating attempts is a critical one in social interactions, little is known about the molecular and cellular mechanisms controlling mammalian sexual preference. Here we report that the neurotransmitter 5-hydroxytryptamine (5-HT) is required for male sexual preference. Wild-type male mice preferred females over males, but males lacking central serotonergic neurons lost sexual preference although they were not generally defective in olfaction or in pheromone sensing. A role for 5-HT was demonstrated by the phenotype of mice lacking tryptophan hydroxylase 2 (Tph2), which is required for the first step of 5-HT synthesis in the brain. Thirty-five minutes after the injection of the intermediate 5-hydroxytryptophan (5-HTP), which circumvented Tph2 to restore 5-HT to the wild-type level, adult Tph2 knockout mice also preferred females over males. These results indicate that 5-HT and serotonergic neurons in the adult brain regulate mammalian sexual preference.  相似文献   

12.
通过长期观察、试验和研究认为,性成熟的棕色田鼠与双亲或雌亲相处或与兄妹鼠相处都不能发情,从而体现亲缘关系对棕色田鼠发情所具有的明显抑制作用。同母喂养的非同胞异性鼠相处能够动情,说明遗传识别在棕色田鼠亲缘识别中起重要作用。非同母喂养的非同胞异性鼠和同母喂养的异性非同胞鼠中的雄性睾丸下降率显大于异性同胞鼠相处时的雄鼠,说明亲缘关系对雄性睾丸下降表现出明显的抑制作用。  相似文献   

13.
稻纵卷叶螟人工饲料的研究   总被引:1,自引:1,他引:0  
 以稻纵卷叶螟为研究对象,按不同配方配制了6种人工饲料分别用来饲养稻纵卷叶螟,以筛选出适合饲养稻纵卷叶螟的人工饲料。结果表明,在温度为24~26 ℃,相对湿度大于80%,光照条件大于14 h的条件下,其中饲料D、E、F饲养稻纵卷叶螟二龄幼虫只能完成二龄发育,少数幼虫存活到三龄或三龄以上;饲料C饲养稻纵卷叶螟二龄幼虫也只能完成三龄发育;而饲料A和B饲养的稻纵卷叶螟二龄幼虫能完成整个世代发育,存活率分别为26.17%和36.40%,接近对照组新鲜水稻叶饲养的存活率36.67%,且蛹质量和新鲜水稻叶饲养的幼虫没有显著差异,但与对照相比,幼虫历期延长4~6 d、化蛹率下降8%~9%、羽化率下降11%~12%。  相似文献   

14.
O'Donald P 《Nature》1977,267(5607):151-154
Models of sexual selection in polygynous species of animals have been derived on the assumption that some females have preferences to mate with males with particular genotypes. The mating advantage gained by the males is always frequency-dependent because the preferred males take part in the same number of preferential matings when they are rare as when they are common; individually therefore, they mate more often when they are rare. Frequency-dependent sexual selection has been demonstrated in many experiments with Drosophila: rare males take part in a higher proportion of matings than their frequency as available mates. Ehrman and Spiess explained this phenomenon by frequency-dependence either in female preference or in male courtship. This explanation, which is difficult to interpret in behavioural terms, may not be necessary, however, because constant female preferences would entail frequency-dependent selection among the males. I show here that a simple model of constant preferences for particular phenotypes or genotypes is sufficient to explain a large body of data on frequency-dependent sexual selection in Drosophila.  相似文献   

15.
T W Teasdale  D R Owen 《Nature》1984,309(5969):620-622
Although it is well established that family members resemble each other in intelligence , the extent to which this results from either shared genes or a shared environment remains controversial, perhaps especially since the relevant evidence presented by Burt has been shown probably to have been fabricated. The influence of heredity and familial environment may be distinguished by studying adoptees. Here we present correlations in intelligence and educational level between genetically related pairs of adult adoptees who have been reared separately, and, conversely, between genetically unrelated pairs of adult adoptees who have been reared together. We are unaware of any previous study of adults which has reported on both of these types of relationship. The results for intelligence conform closely to what would be predicted by a simple polygenic model of genetic transmission whereas those for educational attainment imply both genetic and familial environmental components.  相似文献   

16.
Ozanne SE  Hales CN 《Nature》2004,427(6973):411-412
Poor fetal growth is linked with long-term detrimental effects on health in adulthood. Here we investigate whether the lifespan of male mice is affected by their growth rate when they were suckling and find that limiting growth during that period not only increases longevity but also protects against the life-shortening effect of an obesity-inducing diet later on. By contrast, we find that lifespan is considerably shortened if the postnatal period of growth is accelerated to make up for reduced growth in utero, and that, in addition, these mice are susceptible to the adverse effects on longevity of an obesity-inducing diet after weaning.  相似文献   

17.
Fedorka KM  Mousseau TA 《Nature》2004,429(6987):65-67
Indirect-benefit models of sexual selection assert that females gain heritable offspring advantages through a mating bias for males of superior genetic quality. This has generally been tested by associating a simple morphological quality indicator (for example, bird tail length) with offspring viability. However, selection acts simultaneously on many characters, limiting the ability to detect significant associations, especially if the simple indicator is weakly correlated to male fitness. Furthermore, recent conceptual developments suggest that the benefits gained from such mating biases may be sex-specific because of sexually antagonistic genes that differentially influence male and female reproductive ability. A more suitable test of the indirect-benefit model would examine associations between an aggregate quality indicator (such as male mating success) and gender-specific adult fitness components, under the expectation that these components may trade off. Here, we show that a father's mating success in the cricket, Allonemobius socius, is positively genetically correlated with his son's mating success but negatively with his daughter's reproductive success. This provides empirical evidence that a female mating bias can result in sexually antagonistic offspring fitness.  相似文献   

18.
金线侧褶蛙的两性异形及雌性繁殖特征的研究   总被引:1,自引:0,他引:1  
测定了金线侧褶蛙成体的8个主要形态指标和雌体的怀卵量.结果表明。各形态指标均与体长呈正相关,金线侧褶蛙雌体的体长和体重均显大于雄体.以体长为协变量的协方差分析表明。只有雄体的鼓膜径显大于雌体.而头长、头宽、眼径、前肢长和后肢长不存在明显的两性差异.雌蛙怀卵量与自身体重和体长成正相关.表明该蛙通过增加个体大小增加繁殖输出.  相似文献   

19.
通过形态学比较和12S、16SmtDNA序列比对分析,结果显示分布于浙江省西天目山的花臭蛙(Odorrana schmackeri Boettger,1892)与地模产地花臭蛙以及花臭蛙2个新隐种南江臭蛙和黄岗臭蛙之间存在显著差异,其主要鉴别特征为:1)雌性成体体长约为雄性的1.75倍;2)头长大于头宽,吻端钝尖;3)后肢前伸胫跗关节达眼鼻间;4)趾间全蹼,第4趾两侧及第2、3趾内侧蹼以缘膜达趾吸盘基部;5)背部褐色斑稀疏,形状、大小、排列不规则;6)四肢背面浅褐色横纹宽窄不一,胫部横纹4或5条;7)雄性具1对咽侧下外声囊,背面有肉粉色雄性线,第1指具乳白色婚垫;8)雌性成熟卵动物极棕褐色、植物极米黄色,卵径2.17mm左右.故将浙江省西天目山区的花臭蛙鉴定为一新种--天目臭蛙(Odorrana.tianmuii.sp.nov.).  相似文献   

20.
作者通过研究证明变色沙蜥Phrynocephalus versicolor的繁殖活动具有明显的季节性。雄晰性成熟时最小吻-肛长为45mm,吻-肛长大的雄晰在一年中成熟精子出现早且维持时间长。雌蜥性成熟时的最小吻-肛长为41mm,产卵期为5月末至7月末,每只雌性成蜥每年产卵一次,吻-肛长大的雌蜥产卵多而大且比吻-肛长小的雌晰产卵早。  相似文献   

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