Sex allocation theory proposes that parents should bias the sex ratio of their offspring if the reproductive value of one sex is greater than that of the other. In the monogamous blue tit (Parus caeruleus), males have a greater variance in reproductive success than females, and high-quality ...
Sexual dimorphism, socionomic sex ratio and body weight in primates BECAUSE the primates are a particularly well studied group they provide a rare opportunity to investigate the adaptive significance of species differences ... TH Clutton-Brock,PH Harvey,B Rudder - 《Nature》 被引量: 1195发表: ...
Body mass and sex ratio (F/M) of folivorous insects are easily measured parameters that are commonly used to assess the effect of food quality, living conditions, and preferences on the selection of favourable sites for offspring. A study was conducted on the polyphagous beetle,Gonioctenaquinqu...
CONCLUSIONS: The female-to-male mortality ratio differs for stroke subtypes by race/ethnicity and age. A primary public health effort should focus on increasing the awareness of stroke symptoms, particularly among people at high risk, to decrease delay in early detection and effective stroke ...
Consistent condom use reduces the genital human papillomavirus burden among high-risk men: the HPV infection in men study used condoms (hazard ratio, 0.54), after adjustment for country, age, race, education duration, smoking, alcohol, and number of recent sex partners. The... CMP Campbell,L...
Male–biased investment ratios in eusocial Hymenoptera are assumed to be non-stable for both the queen and her workers. In this paper, we show that male–biased sex allocation does not necessarily decrease fitness in the bumblebee Bombus terrestris. A male–biased investment ratio can be the ...
Sex ratio and sexual dimorphism of Borderea pyrenaica , a long-lived dioecious geophyte endemic to the Pyrenees (north-east Iberian Peninsula), were examined in three alpine populations. In this species, age can be estimated and the sex of nonreproductive adult plants identified. Male plants att...
The evolution of heteromorphic sex chromosomes creates a genetic condition favoring the invasion ofsex-ratiomeiotic drive elements, resulting in the biased transmission of one sex chromosome over the other, in violation of Mendel's first law. The molecular mechanisms ofsex-ratiomeiotic drive may there...
Offspring sex ratio at hatching was examined in the bushcricket Poecilimon veluchianus. Offspring sex ratios varied significantly between females (Fig.?1). Low mortality prior to sex determination established that this heterogeneity was already present in the primary offspring sex ratio. Sperm age ...
Unadjusted cumulative incidence of 1‐year major adverse cardiac events was higher for women than for men (15.7% versus 13.6%, P=0.02), but female sex was no longer associated with higher incidence of major adverse cardiac events after multivariable adjustment (hazard ratio 0.98, 95% CI 0.83 ...