Human reproduction
22. Sugar and spice...
Skip breakfast for a daughter, eat up your cereals for a son

22-1-102
THERE are numerous old wives' tales about how a couple can increase their chances of having a boy or a girl. For a son, make love only on odd days of the month, eat plenty of meat and be sure the father keeps his genitals cool by wearing boxer shorts and loose-fitting trousers; for a daughter, put a wooden spoon under the bed and eat plenty of yogurt.
Although a child's sex is genetically determined by the father, mothers can influence the development of one sex rather than another. Studies in animals and humans suggest that there are links between the sex of a child and the mother's diet and her levels of stress. Although the mechanisms are not well understood, this appears to have evolutionary roots which favour greater reproductive success. Hence in hard times when food might be scarce, daughters were more valuable because their chances of providing offspring would have been greater than sons, who might get killed or fail to find a mate. But in good times sons were a better bet because they could father more children.
Those same evolutionary influences persist in modern life. New research shows a clear link between higher energy intake around the time of conception and the birth of sons-especially by mothers who eat cereals for breakfast.

A. 어휘
skip breakfast 아침밥을 건너뛰어라. cereals 오트밀의 아침식사, 곡물.
odd days 홀수 날자. genitals 생식기.
genetically 유전적으로. influence 영향을 끼치다. mechanism 기계과정, 심리과정.
evolutionary roots 진화론적 근거. favour 편애하다, 혜택을 베풀다.
reproductive success 生殖(생식)의 성공. scarce 부족하다. offspring 자손.
bet 내기, 도박. father ...을 낳다. persist in 존속하다, 고집하다.
conception 受胎(수태), 임신, 개념.