scholarly journals The Relationship Between Offspring Sex Ratio and Vasectomy Utilization

Urology ◽  
2017 ◽  
Vol 103 ◽  
pp. 112-116 ◽  
Author(s):  
Remy W. Lamberts ◽  
David P. Guo ◽  
Shufeng Li ◽  
Michael L. Eisenberg
Keyword(s):  
Sex Ratio ◽  
Offspring Sex Ratio ◽  
Offspring Sex ◽  
The Relationship

The Effects of Polygyny and Domicility on Offspring Sex Ratio in Ghana

2007 ◽  
Vol 6 (4) ◽  
pp. 431-456
Author(s):  
Adansi Amankwaa
Keyword(s):  
Sex Ratio ◽  
Family Structure ◽  
Living Arrangements ◽  
Living Arrangement ◽  
Demographic And Health Surveys ◽  
Offspring Sex Ratio ◽  
Ratio Bias ◽  
Sex Ratio Bias ◽  
Offspring Sex ◽  
The Relationship

AbstractThis article explores how family structure and domicility influences offspring sex ratio bias, specifically living arrangements of husband in polygynous unions. Data from three Ghana Demographic and Health Surveys were used to examine the relationship between family structure and offspring sex ratio at birth, something that previous studies have not been able to do. This study estimate models of sex ratio offspring if the wives live together with husband present and wives live in separate dwellings and are visited by husband in turn. The results suggest that within polygynous marriages there are more male births, especially when husbands reside in the same dwelling as wives, than when husbands reside in separate dwellings from their wives. The analyses show that offspring sex ratio is related to the structure of living arrangement of husbands in polygynous unions. Indeed, the findings suggest that living arrangements and family structure among humans are important factors in predicting offspring sex ratio bias.

scholarly journals Covariance of paternity and sex with laying order explains male bias in extra-pair offspring in a wild bird population

2013 ◽  
Vol 9 (5) ◽  
pp. 20130616 ◽  
Author(s):  
Oscar Vedder ◽  
Michael J. L. Magrath ◽  
Marco van der Velde ◽  
Jan Komdeur
Keyword(s):  
Sex Ratio ◽  
Wild Population ◽  
Cyanistes Caeruleus ◽  
Offspring Sex Ratio ◽  
Bird Population ◽  
Male Bias ◽  
Laying Order ◽  
Offspring Sex ◽  
The Relationship ◽  
Blue Tits

It has been hypothesized that parents increase their fitness by biasing the sex ratio of extra-pair offspring (EPO) towards males. Here, we report a male bias among EPO in a wild population of blue tits ( Cyanistes caeruleus ). This resulted from a decline in both the proportion of males and EPO over the laying order of eggs in the clutch. However, previous studies suggest that, unlike the decline in EPO with laying order, the relationship between offspring sex ratio and laying order is not consistent between years and populations in this species. Hence, we caution against treating the decline in proportion of males with laying order, and the resulting male bias among EPO, as support for the above hypothesis. Variable patterns of offspring sex and paternity over the laying order may explain inconsistent associations between offspring sex and paternity, between and within species.

scholarly journals Does the Mother or Father Determine the Offspring Sex Ratio? Investigating the Relationship between Maternal Digit Ratio and Offspring Sex Ratio

PLoS ONE ◽  
2015 ◽  
Vol 10 (11) ◽  
pp. e0143054 ◽  
Author(s):  
Tae Beom Kim ◽  
Jin Kyu Oh ◽  
Kwang Taek Kim ◽  
Sang Jin Yoon ◽  
Soo Woong Kim
Keyword(s):  
Sex Ratio ◽  
Digit Ratio ◽  
Offspring Sex Ratio ◽  
Offspring Sex ◽  
The Relationship

Offspring sex ratio in moose Alces alces in relation to paternal age: an experiment

2004 ◽  
Vol 10 (1) ◽  
pp. 51-57 ◽  
Author(s):  
Bernt-Erik Sæther ◽  
Erling J. Solberg ◽  
Morten Heim ◽  
John E. Stacy ◽  
Kjetill S. Jakobsen ◽  
...  
Keyword(s):  
Sex Ratio ◽  
Alces Alces ◽  
Paternal Age ◽  
Offspring Sex Ratio ◽  
Offspring Sex

Breeding system can affect the offspring sex ratio in Syrian hamsters

2011 ◽  
Vol 45 (1) ◽  
pp. 55-57 ◽  
Author(s):  
M O M Chelini ◽  
N L Souza ◽  
E Otta
Keyword(s):  
Sex Ratio ◽  
Breeding System ◽  
Offspring Sex Ratio ◽  
Syrian Hamsters ◽  
Offspring Sex

scholarly journals Is biasing offspring sex ratio adaptive? A test of Fisher's principle across multiple generations of a wild mammal in a fluctuating environment

2018 ◽  
Vol 285 (1891) ◽  
pp. 20181251 ◽  
Author(s):  
Andrea E. Wishart ◽  
Cory T. Williams ◽  
Andrew G. McAdam ◽  
Stan Boutin ◽  
Ben Dantzer ◽  
...  
Keyword(s):  
Sex Ratio ◽  
Tamiasciurus Hudsonicus ◽  
Red Squirrels ◽  
Offspring Sex Ratio ◽  
Offspring Sex ◽  
Adult Sex Ratio ◽  
Secondary Sex Ratio ◽  
North American Red Squirrels ◽  
Negative Frequency Dependent Selection ◽  
Fisher’S Principle

Fisher's principle explains that population sex ratio in sexually reproducing organisms is maintained at 1 : 1 owing to negative frequency-dependent selection, such that individuals of the rare sex realize greater reproductive opportunity than individuals of the more common sex until equilibrium is reached. If biasing offspring sex ratio towards the rare sex is adaptive, individuals that do so should have more grandoffspring. In a wild population of North American red squirrels ( Tamiasciurus hudsonicus ) that experiences fluctuations in resource abundance and population density, we show that overall across 26 years, the secondary sex ratio was 1 : 1; however, stretches of years during which adult sex ratio was biased did not yield offspring sex ratios biased towards the rare sex. Females that had litters biased towards the rare sex did not have more grandoffspring. Critically, the adult sex ratio was not temporally autocorrelated across years, thus the population sex ratio experienced by parents was independent of the population sex ratio experienced by their offspring at their primiparity. Expected fitness benefits of biasing offspring sex ratio may be masked or negated by fluctuating environments across years, which limit the predictive value of the current sex ratio.

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