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71.
72.
司马光家族延续了上千年,家谱记载较为完整,为谱牒学、历史学、遗传学等人文和自然学科的跨学科研究提供了较好的材料。本研究对11个声称为司马光后代的家族进行了Y-STR分型,结果表明有5个家族的STR单倍型彼此之间十分接近,同属下游单倍群O1a1a1a1a1a-F492+,F656-。因此,我们推断司马光家族的父系遗传类型极有可能属于此单倍群。同时,我们使用BATWING法逐层计算所有支系的最近共祖时间,其结果与根据谱牒资料构建的家族谱系图非常吻合。本项研究为从遗传学角度研究现代家族的父系谱系和重构家族谱牒材料提供了参考,并将有助于进一步研究汉代史学家司马迁家族以及西晋司马王室的源流。  相似文献   
73.
Synopsis Direct observation and the analysis of stomach contents indicate that custodial male Cortez damselfish, Stegastes rectifraenum, regularly eat some of the eggs they fertilize and guard. The pattern of forced starvation and brood cycling by custodial males that is seen in sticklebacks and other fishes for which filial cannibalism is known in the field does not exist for this species. These results indicate that filial cannibalism is likely to be more common among fishes than previously thought, because this behavior is not restricted to species that brood cycle.  相似文献   
74.
In biparental species, females are thought to accept and even to seek male assistance in rearing of the young. In this study, we present data that suggests that Goeldi's monkey females (Callimico goeldii) actually reject male parental care for a certain period. In Callimico, which have biparental care, mothers carry the infant exclusively for the first three weeks despite the fact that fathers are interested in their infants directly after birth. Fathers initiated significantly more body contact with their mates when newborn infants were present and retrieved one-day-old infants that were experimentally presented to them. The onset of paternal carrying in our colony was 27.5 days compared to 11.5 days (medians) observed in the field. However, presentation of a live potential predator induced earlier onset of paternal carrying by about 10 days. Additional costs to maternal carrying such as foraging and predator avoidance are likely factors influencing the decision of the mother as to when to share the cost of infant carrying with the father. We conclude that Goeldi's monkey fathers start carrying their infants so late because they do not get them earlier from the mother. We suggest that one ultimate explanation for that delay might be increased infant mortality when infant transfer starts at an earlier stage.  相似文献   
75.
The present study argues that pressures associated with the threat of paternal uncertainty shaped a male mate-preference for relatively subordinate partners in the context of long- (high investment) but not short-term (low investment) relationships. Using a hypothetical scenario depicting a workplace setting, 120 male and 208 female undergraduates were randomly assigned to one of six experimental conditions in which they were asked to judge a male or female target, described as either their supervisor (higher dominance), coworker (equal dominance), or their assistant (lower dominance). Participants exposed to an opposite-sex target rated their attraction to the target for varying types of investment (e.g., desire for a one-night stand, desire to affiliate, or desire for a long-term relationship), and participants exposed to a same-sex target rated their desire to affiliate with the target. Results supported predictions and indicated that males preferred the subordinate over the dominant target for affiliation and high-investment items, and females were unaffected by the target's dominance status. The results of same-sex ratings indicated that dominance status did not influence females' ratings of the female target, and that dominance did not influence males' ratings of the male target. These results are discussed in terms of the role of relational dominance in shaping male mate-preferences.  相似文献   
76.
We used a longitudinal design to test whether parental experience differentially affects the development of prolactin responses to infant cues in men and women. Couples provided two blood samples at three tests, one test just before their babies were born, and two tests during the early postnatal period (n=21). Nine couples repeated the tests near the birth of their second babies. In the 30 min between the two samples, couples listened to recorded infant cries at the prenatal test and held their baby (fathers) or a doll (mothers) at the postnatal tests. Blood samples were analyzed for prolactin concentrations. Prolactin values were then related to sex and parity differences as well as to questionnaire data concerning emotional responses to infant cries and previous infant contact. We found that (1) prior to the birth of both the first and second babies, women's prolactin concentrations increased after exposure to infant stimuli, whereas men's prolactin concentrations decreased; postnatal sex differences varied with parity; (2) women's prolactin reactivity did not change significantly with parental experience; (3) the same men's prolactin concentrations decreased after holding their first newborns but increased after holding their second newborns; this change was not gradual or permanent; (4) men reporting concern after hearing recorded infant cries showed a different postnatal pattern of prolactin change after holding their babies than men not reporting concern; and (5) men who had little contact with their babies just prior to testing had a more positive prolactin response than men who had recently held their babies for longer periods. Although parental experience appears to affect men's prolactin responses, differences in reactivity were also related to patterns of recent infant contact and individual differences in responses to infant cues.  相似文献   
77.
我国广西的桂东北地区大约有20,000人使用茶洞话,该群体的族源问题一直存在争议。本文为调查茶洞话群体的Y染色体遗传结构,探讨其父系起源,对临桂县使用茶洞话的21名无关男性个体的Y-STR和Y-SNP进行了检测分型,并对该群体与周边民族的遗传关系进行了研究分析。结果显示:茶洞话群体的17个Y-STR位点具有丰富的遗传多态性,适用于群体遗传学和法医学研究;Y染色体高频单倍群为O2*-P31和O2a1*-M95,表明茶洞话群体具有显著的百越民族系统侗傣族群的遗传背景;N-J树和主成分分析显示茶洞话群体与仫佬族的父系遗传关系较之与毛南族和汉族更亲近。本研究结果为茶洞话群体的族源研究提供了遗传学证据。  相似文献   
78.
Synopsis The spatial distribution and parental care of demersal egg masses of buffalo sculpin (Enophrys bison) were studied at 11 areas in Puget Sound, Washington, during 1972–1973. Adult buffalo sculpin inhabited rock and rock-sand habitats at depths from the intertidal to minus 20 m throughout the year, but 84% of all spawn clusters were found at depths between –1 m and +1 m within localized rocky areas. Areas used for spawning were exposed to strong tidal currents and other water movements. A single male fish guarded and fanned spawn, but eggs were temporarily deserted when less than about 1 m of water covered the spawning site. The cyclical nature of male desertion, behavior of spawn predators, and spawn mortality due to physical factors while emergent suggest several possible advantages to low intertidal spawning. These advantages include spatial and temporal escape from marine predators by embryos, time for the tending parent to forage, and optimal physical conditions for embryonic development.  相似文献   
79.
Summary B chromosomes are often considered genomic parasites. Paternal sex ratio (PSR) is an extreme example of a parasitic B chromosome in the parasitoid waspNasonia vitripennis. PSR is transmitted through the sperm of carrier males and destroys the other paternal chromosomes in early fertilized eggs. PSR disrupts the normal haplodiploid sex determination in this wasp by converting diploid (female) eggs into haploid (male) eggs that bear PSR. In this study I compare a number of phenotypic fitness aspects of PSR and standard (non-PSR) males. In general, PSR males were as fit as standard males. No significant differences were found in longevity (with one exception), ability to compete for mates and sperm depletion rates. PSR males produced 11–22% larger family sizes and developed slightly faster than standard males. Under conditions of sperm competition, females who mated with both types of males fertilized a constant proportion of eggs with each sperm type over their lifetime. PSR males produced fewer offspring among progenies from double-inseminated females. Phenotypic fitness effects are believed to play a minor role in determining PSR frequencies in natural populations.  相似文献   
80.
Paternal care is necessary for the healthy development of social behavior in monogamous rodents and social recognition underpins social behavior in these animals. The effects of paternal care on the development of social recognition and underlying neuroendocrine mechanisms, especially the involvement of oxytocin and estrogen pathways, remain poorly understood. We investigated the effects of paternal deprivation (PD: father was removed from neonatal pups and mother alone raised the offspring) on social recognition in mandarin voles (Microtus mandarinus), a socially monogamous rodent. Paternal deprivation was found to inhibit the development of social recognition in female and male offspring according to a habituation–dishabituation paradigm. Paternal deprivation resulted in increased inactivity and reduced investigation during new encounters with other animals. Paternal deprivation reduced oxytocin receptor (OTR) and estrogen receptor α (ERα) mRNA expression in the medial amygdala and nucleus accumbens. Paternal deprivation reduced serum oxytocin (OT) concentration in females, but had no effect on males. Our results provide substantial evidence that paternal deprivation inhibits the development of social recognition in female and male mandarin voles and alters social behavior later in life. This is possibly the result of altered expression of central OTR and ERα and serum OT levels caused by paternal deprivation.  相似文献   
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