云南省人口的性比

对云南省1990年人口普查时的性比(男:女100)进行了分析研究,发现:(1)云南省总人口的性比(105.67)比1982年人口普查时提高了2.89,比全国的(106.60)仅低0.93,开始高出“性比较为严衡状态”(1003.5:1000),为1005.3:1000,且后8年年均递升速度为1982年的18年的2.19倍。(2)景颇族的性比特别低(95.77),而汉族0—14岁儿童性比则为107.27。(3)云南“大跃进”与“国民经济暂时旧难”时期出生的人,1982年”三普”时(20—24岁)性比特别低(101.11),可1990年“四普”时(28—32岁)却达107.84。(4)城镇人口的性比(113.01),比农村入门的性比(105.67)高得多,但差异在减小,(5)全省各地人口性比不同。     

云南大理白族自治州人口的性比

作者于1986年在《人类学学报》第5卷2期上发表了《云南玉溪地区人口的性比》一文,对云南玉溪地区1982年人口普查时的性比进行了分析,现将云南大理白族自治州同年人口普查时的性比材料报道如下。     

出生性比研究

对 1971— 1993年云南昆明、玉溪、红河、思茅、西双版纳、大理、楚雄、丽江等 8地、州、市 66个医疗单位接生的新生儿资料进行调查 ,获取401454例新生儿性别等有关资料。发现 :( 1 )出生性比在上升 ,由 1971年的 104 .06上升到 1993年的 108.57;1974年最低 ,为 101 .11 ,1991年最高 ,为 111 .87。 23年中 ,平均每年上升 0 .47。 ( 2 )一年之中 ,新生儿出生人数的高峰期为 10、 11、 12等 3个月 ,峰顶为 11月 ,占 11 .01% ;出生性比的峰顶为 3、4、6、7、9等5个月 ,最高为 9月 ,达 109.47。 ( 3)城、乡出生性比差异显著。不论胎次 (一、二胎 )和月份 ( 8、 9两月除外 ) ,市、县城区 ,出生性比均显著高于农村。 ( 4) 1 979年以前的出生性比在101 .11— 105 .67之间 ,1980年以后的出生性比在 104 .17— 111 .87之间。 ( 5 )提出了维持性平衡的6点对策。     

植物种群的性比

总结了植物种群性比的最新研究成果,阐明了自然界植物不同性别的个体间的差异、影响植物种群性比的因素和有关种群性比变化的机理,论述了种群性比变化研究的理论和实践意义.     

云南苗族的体质特征研究

为了解云南苗族的体质特征,我们于１９８７年５月间,赴昆明市禄劝苗族彝族自治的翠华山区螳螂菁附近山寨进行了有关项目调查,并将结果整理如下,以期对云南苗族的体质人类学特征有所了解。     

圈养大熊猫种群性比失衡现象产生机制的探究

大熊猫(Ailuropoda melanoleuca)的迁地保护工作已开展了近70年,基本实现了圈养种群的自我维持。根据2019年大熊猫谱系,现存圈养大熊猫种群(n=612)的总性比为1.22∶1 (♀336/♂276),与1∶1的性比有显著性差异(P=0.015),目前尚未开展性比失衡现象产生机制的探究工作。本研究以全国最大的圈养大熊猫种群为研究对象,梳理了该种群36年的出生性比、11年的分年龄雌雄个体数量和分年龄死亡雌雄个体数量,计算了出生性比和预期寿命等数据,旨在探究性比失衡的内在原因。结果显示,圈养大熊猫种群的出生性比为1.01∶1,与1∶1的性比无显著性差异(P=0.926);雄性大熊猫在幼年阶段死亡的比例高于雌性(♀38.24%/♂48.72%);圈养大熊猫的出生预期寿命中位数为21.4岁,其中雌性为23.5岁,雄性为19.8岁,雌性预期寿命比雄性长3.7岁。研究表明,圈养大熊猫种群性比失衡的内在原因是雄性大熊猫幼年阶段的死亡比例高于雌性,且雌性大熊猫预期寿命更长。本研究聚焦圈养大熊猫种群的性比失衡问题,首次计算了圈养大熊猫的预期寿命,可为圈养大熊猫种群的饲养管理和野外大熊...     

高原鼠兔种群的性比

The sex ratio (♂ / ♀ ) of plateau pika's (Ochotona curzoniae) population was studied by re-captured method in the region of the Haibei Mpine Meadow Ecosystem Research Station, Northwest Institute of Plateau Biology, the Chinese Academy of Sciences from April of 2001 to August of 2002. The result showed that there was no significant difference from 1:1 in adult's sex ratio in whole breeding season, whereas the sex ratio of juvenile had some fluctuations among different age stages. The sex ratio of the second litter varied significantly from embryo to 60-day-old, but no difference at the first and the third litter. We concluded it was caused by conflict between maternal strategy and juvenile's strategy. No significant differences of sex ratio were found both in adult and juvenile between 2001 and 2002. The sex ratio of plateau pika before and after overwintering did not vary. In summary,we proposed that sex ratio of plateau pika's population was not influenced by exogenous factors, but some serf-regulation mechanisms may be involved.     

甘肃鼢鼠种群性比的研究

本文对甘肃鼢鼠种群的性比及性比的季节,年度和年龄组的变化进行了研究,并对种群性比与月平均气温,降水量等环境因子间的关系进行了分析,结果表明,甘肃鼢鼠种群的总性比（♀／♂）为１．５７,雌性明显多于雄性（Ｘ＾２＝４７．６,Ｐ〈０．０１）,并且,种群性比存在明显的季节和年龄变化,但性比的年度变化不明显,在４－８月份鼢鼠繁殖期,月降水量〈５ｍｍ,或月降水量〉４０ｍｍ的月份,月降水量与其后一月鼢鼠种群性比之     

白头叶猴的性比与社会结构

白头叶猴的性比与社会结构ＳＴＵＤＹＯＮＳＥＸＲＡＴＩＯＡＮＤＳＯＣＩＯ－ＳＴＲＵＣＴＵＲＥＯＦＦＷＨＩＴＥ－ＨＥＡＤＥＤＬＥＡＦＭＯＮＫＥＹＫｅｙｗｏｒｄｓＷｈｉｔｅ－ｈｅａｄｅｄｌｅａｆｍｏｎｋｅｙ;Ｓｅｘｒａｔｉｏ;Ｓｏｃｉｏ－ｓｔｒｕｃｔｕｒｅ...     

乌苏里江哲罗鲑的年龄结构、性比和生长

We report the current status of Taimen (Hucho taimen ) population in Wusuli River of China. The amount of catch per year was only 1 800 - 5 400 individuals ranging from 2 - 15 years old during 1998 - 2002. Of all the captured, individuals with sexual maturity were up to 30% - 70% (female maturity at 5 years old and male 6 years old). Sex ratio varied greatly among different localities. Its breeding population mainly consisted of males aged 5 - 10 years and females aged 8 - 13 years‘‘old, which spawned in May each year. Females breed once with about 4 000 - 23 000 eggs produced every 2 - 3 years, Taimen grows fast and average growth rate is about 10 cm per year prior to 10 years‘‘s old, which corresponded with von Bertelanffy‘‘s equation calculated as Lt = 246.41 [ 1 -e 0.0407(t 0.4625)] and Wt = 174 075.72 [ 1 -e ^0.0407(t-0.4622)12.9537, and the relationship between body length and weight was W 0.015018L^u2020.     

Multilocus autosomal sex determination

The two basic one locus sex determination models, diploid individual sex determination and parental sex determination, are generalized to the multilocus framework. As in the single locus case, it is established that there are two classes of polymorphic equilibria, equilibria with even sex ratio and equilibria with equal allele frequencies in the two sexes. The condition for external stability of this second class equilibria to invasion by a new mutant allele is that a new appropriately averaged sex ratio near the equilibrium be moved closer to the even sex ratio. However, stable polymorphisms with noneven sex ratio are not those that have a sex ratio as close as possible to 1/2, in contrast to the single locus case.Research supported in part by NIH grants GM 28016 and GM 10452 and a grant from the U.S.-Israel Binational Science Foundation     

Hypothetical role of men's sexual activity in the regulation of human sex ratio: Analysis of the sex ratio of post-war abandoned children

The regulation of the sex ratio at birth in human species remains poorly understood. After wars, a shift of the sex ratio in favor of men is always observed. Among the different hypothesis to explain this observation, one is to consider that Y-bearing spermatozoids have a weight advantage following insemination and that X-bearing spermatozoids, heavier, are more time-resistant. Following these observations, frequent sex may favor the birth of boys, whether infrequent sex may favor the birth of girls.Sustaining this sperm weight hypothesis, I report here that in France, after the two world wars, there has been an increase of abandoned illegitimate children with a significant shift of the sex ratio in favor of men. These observations may reflect an increase in illegitimate birth and indirectly an increase of men paternity.     

Are mistakes inevitable? Sex allocation specialization by workers can reduce the genetic information needed to assess queen mating frequency

Insect workers can increase their inclusive fitness by biasing colony sex allocation towards males when their mother queen is mated to multiple males and females when she is singly mated. Workers need heritable variation in odour diversity to assess queen mating frequency. Here we present a simple one-locus two-allele model, which shows that the sex ratio specialization itself will often select against rare alleles that would provide additional information for the assessment of queen mating frequency. However, under certain rather restricted conditions, such as when sex ratios are highly female biased, and when worker reproduction is rare, sex ratio specialization can select for rare alleles. This suggests that sex allocation biasing by workers will usually reduce the very information that workers need to assess queen mating frequency. Our model is an example where an explicit treatment of underlying genetics and mechanisms of behaviour, such as information use, is necessary to fully understand the evolution of an adaptive behavioural strategy.     

中国汉族锁骨的性别判定

本文通过对279副中国汉族成人锁骨的测量,其中男性241副,女性38副。使用性别判别分析的方法,建立了锁骨性别判别的分析式,使中国汉族锁骨性别判别的准确率达到了90－94．7％,该文提出的性别判别方法,是锁骨性别判别的准确可靠的方法。     

中国汉族锁骨性别差异的初步研究

本文通过对中国汉族２７９副成人干燥锁骨的测量（其中男性：２４１副,女性：３８副）,研究了中国汉族锁骨性别判定的方法,研究结果表明,用单一指标进行锁骨的性别,准确率很低,本文作者提出了锁骨表面积指数,锁骨截面积指数,并以此作为锁骨性别判定的依据,性别判别率最高可分别为９０．６８％和８４．２３％。本文提出的方法是骨骼性别判定中一种新的简单而准确的方法。     

温度对江黄颡鱼性分化的影响

通过组织学方法观察江黄颡鱼原始生殖细胞(PGCs)迁移、生殖嵴生成和性腺分化,并且探讨在不同温度培育下性腺分化的差异。实验结果显示:1日龄仔鱼PGCs位于鱼体中肠背方的脏壁中胚层中;5日龄时,PGCs迁移到背方的腹膜上皮;8日龄时,生殖嵴形成;14日龄时,原始性腺形成;23日龄时,性腺开始分化。从孵化后的第10天开始,分别用(20±0.5)、(24±1.0自然水温、对照组)、(30±0.5)和(34±0.5)℃4种水温培育仔鱼达25天。实验结束后统计结果显示:对照组和(20±0.5)℃组的雌、雄性比接近1∶1(分别为1∶1.09和1.22∶1);(30±0.5)℃组的为1∶4.89,雄性率达(83.3±0.7)%;(34±0.5)℃组的为2.85∶1,雄性率仅为(26.4±0.4)%。提示(30±0.5)℃可使幼鱼性腺发育趋向雄性,(34±0.5)℃则使幼鱼性腺发育趋向雌性。实验结果表明,江黄颡鱼的性分化是属于温度依赖型性别决定。     

Developments in the identification of human skeletal material (1968-1978).

A review of publications over the last ten years of methods in the field of physical anthropology for determining age, sex, race and stature of human skeletal material is presented. Comparisons are made with the types of papers published in the previous ten years (1958-1968) in six categories: (1) Visual examination of bones (2) Anthropometric measurements of bones (3) Anthropometric measurements with subsequent use of statistics in the form of discriminate function analyses (4) Time and sequence of eruption of the teeth (5) X-ray examination of the internal structure of bone sections (6) Microscopic examination of the internal structure of bone.