Remarkably high sex ratios at birth have been observed recently in Asian populations. 高出生性别比常常发生在亚洲的人口中。
What happens to the sex ratio at birth if fertility is maintained at a low level depends on the evolution of son preference. 如果生育率维持在低水平上，出生性别比的前景取决于男孩偏好的演化。
