منابع مشابه
Sex Ratio Elasticity Influences the Selection of Sex Ratio Strategy
There are three sex ratio strategies (SRS) in nature-male-biased sex ratio, female-biased sex ratio and, equal sex ratio. It was R. A. Fisher who first explained why most species in nature display a sex ratio of ½. Consequent SRS theories such as Hamilton's local mate competition (LMC) and Clark's local resource competition (LRC) separately explained the observed deviations from the seemingly u...
متن کاملOpposing effects of mortality factors on progeny operational sex ratio may thwart adaptive manipulation of primary sex ratio
Despite extensive research on mechanisms generating biases in sex ratios, the capacity of natural enemies to shift or further skew operational sex ratios following sex allocation and parental care remains largely unstudied in natural populations. Male cocoons of the sawfly Neodiprion abietis (Hymenoptera: Diprionidae) are consistently smaller than those of females, with very little overlap, and...
متن کاملInvestigation of growth parameters, mortality and sex ratio of stellate sturgeon (Acipenser stellatus Pallas, 1771) from the southern of Caspian Sea
The aim of this study was to record growth parameters, mortality and sex ratio of Stellate Sturgeon (Acipenser stellatus) from the south basin of the Caspian Sea. 894 specimens were caught by fixed gill net and beach seine during April 2010 to March 2014. Male to female sex ratio was obtained 1:1.05 that was not differed significantly (p>0.05). The minimum and maximum length of the fish specime...
متن کاملSurvey of Sex Ratio with Intracytoplasmic Sperm Injection
Abstract Introduction: In different studies worldwide, gender ratios derived from ICSI (Assisted reproductive techniques) have been reported differently. Objective: Evaluation of neonatal gender in ICSI women referred to Mehr Infertility Research Center of Rasht. Materials and Methods: In this descriptive-analytical study, the cases of infertile women referred to Mehr Infertility Research Ce...
متن کاملSex determination by the length ratio of metacarpals and phalanges: X-ray study on Iranian population
Background: In forensic anthropological identification, we usually use body remains. Accurate sex estimation from these remains is very important and needs the knowledge of specific population standards of that area. Sometimes, human remains are damaged by environmental circumstances. So, we must examine single bones for sex estimation. One of the relatively resistant bones to environmental con...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Epidemiology and Infection
سال: 1944
ISSN: 0950-2688,1469-4409
DOI: 10.1017/s0022172400013012