As natural experiments, famines provide a unique opportunity to test the health
consequences of nutritional deprivation during the critical period of early life. Using data on …

Given an equal sex ratio at conception, the excess of human males at birth can only be
explained by greater loss of females during pregnancy. It is proposed that the bias against …

Objective The normal male to female livebirth sex ratio ranges from 1.03 to 1.07. Higher
ratios in China, India and Korea reflect prenatal sex selection. We reviewed sex ratios for US …

Abstract Purpose of Review Evolutionary hypotheses on the ratio of males to females at birth
posit that women terminate pregnancies with low likelihood of surviving and producing …

Objectives We aim to contribute to the literature reporting tests of selection in utero. The
theory of reproductive suppression predicts that natural selection would conserve …

BACKGROUND The argument that women in stressful environments spontaneously abort
their least fit fetuses enjoys wide dissemination despite the fact that several of its most …

Hypotheses on the stability and variation of human sex ratios at birth - ScienceDirect Skip to
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ABSTRACT On November 4, 2008, Barack Obama was elected the first Black President of
the United States. His campaign and electoral win served as a symbol of hope for a more …

Emerging theory and empirical work suggest that the 'Bruce Effect', or the increase in
spontaneous abortion observed in non-human species when environments become …

Diabet. Med. 29, e273‐e278 (2012) Abstract Aims It has long been hypothesized that natural
selection would favour a reproductive strategy biased towards females under adverse …