Pregnant women are more likely to hear "It's a girl!" when giving birth
during famine conditions than when times are flush, according to a new
study of the 1959-1961 Great Leap Forward famine in China.
The study reveals a dip in the ratio of boys born per girl during the
famine years in the country, Shige Song, a demographer and sociologist
at Queens College of the City University of New York, reports today
(March 27) in the journal Proceedings of the Royal Society B. It's not
entirely clear what causes this dip, but evolutionary theory suggests
that baby boys may be a genetic gamble for parents, and thus not the
best bet when times are lean.
"Investment on male children is a high-risk, high-return game, so you
want to do it only if you are in very good situation," Song told
LiveScience.
Boys and girls
This theory has been around since the 1970s. Males can father lots of
offspring, Song explained, so a successful male child has a good chance
of passing on genes. But when males fail to mate, they tend to do so
spectacularly - a non-dominant lion in a pride ruled by alpha male is
pretty unlikely to get a chance to pass on his genes even once, Song
said.
"In the evolutionary sense, the parental investment on these male lions
would be wasted," he said...
Read more here
http://news.yahoo.com/hard-times-mean-fewer-baby-boys-study-suggests-004
607178.html
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