快猫短视频

THE hazards of childbirth rather than unequal food distribution dictate how
much smaller women are than men, says a team of scientists.

In all human populations, men tend to be taller, but the difference varies
between different parts of the world. The height gap is most pronounced in
European countries, while in Africa women and men are closer in height than
anywhere else.

Some researchers suggest that the most pronounced differences occur in
well-nourished populations because males are more vulnerable to nutritional
deficiencies than females during early development鈥攚hich might stunt the
growth of men in poor countries.

Others have suggested that women would be taller relative to men in societies
where women contribute more to food production鈥攁nd are therefore deemed
valuable enough to get their fair share at mealtimes.

But a team of French and Russian biologists say childbirth is the key.
Jean-Fran莽oise Gu茅gan of France鈥檚 National Centre for Scientific
Research (CNRS) in Montpellier and colleagues studied a range of factors that
may influence patterns of male and female height differences around the world.
Only birth rate and maternal deaths during delivery provided a consistently good
indicator of the gender height gap in a given population.

Gu茅gan and colleagues conclude that short mothers are more likely to
die in childbirth than their taller counterparts. In societies with high birth
rates and poor healthcare this would select in favour of large mothers, reducing
the height gap between men and women.

Gu茅gan told 快猫短视频: 鈥淧ut another way, the high sexual
dimorphism we observe in richer countries is in part due to the fact that
obstetric and sanitary conditions permit all pregnant women to have babies
whatever their pelvis size.鈥�